"Providing pregnant women with iodine supplements could boost children’s intelligence and save thousands of pounds in future health costs," The Daily Telegraph reports.
Iodine is a chemical element found in seawater, rocks and some types of soil. Good food sources include sea fish and shellfish.
Iodine is important for healthy brain development and there is some evidence that UK women might not be getting enough iodine.
This study modelled how the costs of giving women iodine pills during pregnancy – something that is not currently recommended in England – weighed up against the benefits.
It found that giving iodine to pregnant women could potentially boost the IQ of infants by 1.22 IQ points and save the NHS £199 per pregnant woman. Wider societal savings – such as better educational achievement, leading to higher incomes in later life – were even higher, at about £4,476 per woman.
These are all estimates that are only as reliable as the data used to inform them, which in this case may have some errors. For example, the effects of iodine on children’s IQ came from three observational studies, which cannot prove cause and effect.
There is no current recommendation in the UK to take iodine supplements during pregnancy, and you should be able to get all the iodine you need by eating a varied diet.
If you do choose to take iodine supplements, do not take more than 0.5mg (milligrams) a day, as this could be harmful.
Where did the story come from?
The study was carried out by researchers from the University of Birmingham and the National University of Singapore, and received no financial support.
The study was published in the peer-reviewed medical journal The Lancet – Diabetes & Endocrinology.
The Daily Telegraph, BBC News and The Independent headlines highlighted the potential benefits of iodine pills to babies and the NHS purse. By contrast, the Daily Mail’s headline focused purely on the potential brain boost to the baby. The study itself did not investigate whether iodine supplements in pregnancy boost a child’s IQ. This was assumed based on previous research – not reviewed here – before being fed into a model estimating the impact of giving iodine to iodine-deficient pregnant women.
There are no new official UK recommendations to take iodine supplements during pregnancy.
What kind of research was this?
This was a systematic review feeding into an economic evaluation aiming to look at how the costs of iodine supplementation for pregnant women weigh up against the benefits.
Previous research is said to have demonstrated that mild to moderate iodine deficiency is quite widespread during pregnancy and may be associated with reduced cognitive (thinking) ability in the child. As the study authors say, reduced intelligence may cost a person and wider society, as it potentially influences educational attainment, future income and wellbeing.
The UK does not currently recommend iodine supplements during pregnancy. Neither does the UK fortify any food substances or salt with iodine, as an increasing number of other countries are said to do. The researchers in this study aimed to look at the cost-effectiveness of iodine supplements compared with no supplements for pregnant women with mild to moderate iodine deficiency.
What did the research involve?
This study fed past research data on iodine deficiency in pregnant women and its effects on the child into a newly-built mathematical model. It used this to predict the likely effect of giving women iodine pills during pregnancy to address the deficiency. It predicted the effect on the child’s intelligence – measured by IQ score, the cost impact to the NHS, and the cost impact to wider society.
The model was based on a range of assumptions derived from previous research, namely that:
- lower IQ leads to lower income (systematic reviews and expert opinion)
- iron deficiency in pregnant women lowers child IQ (three cohort studies)
- iron deficiency is relatively common in UK women (one cohort study)
The model considered adverse effects linked to excess iodine, principally thyroid problems, such as overactive thyroid (hyperthyroidism) in the mother.
Costs of supplementation were from a UK perspective. In one analysis, they just looked at direct healthcare costs. In their second analysis, they considered the societal perspective – for example, looking at the cost of education and of increasing the IQ of the child.
What were the basic results?
Overall, the model predicted that giving iodine supplementation to address iodine deficiency in pregnant women would be beneficial, compared to not giving supplements.
Looking at overall healthcare costs, iodine supplementation was predicted to save £199 per pregnant woman and to increase the IQ of future infants by around 1.22 IQ points.
Looking at the wider societal perspective, iodine supplementation was predicted to save a lot more – around £4,476 per pregnant woman – for the same 1.22 point IQ boost in each infant.
The lifetime earnings gain from an additional IQ point was predicted to be about £3,297 based on eight studies, but estimates varied a lot between studies, from as low as £1,313 to as high as £11,967.
The researchers estimated that if iodine supplementation caused thyroid dysfunction in a pregnant woman, this would need to cost more than £91,000 to counter the overall benefits arising from supplementing iodine-deficient pregnant women who didn’t see any adverse effects on their thyroid function.
How did the researchers interpret the results?
The researchers conclude: "Iodine supplementation for pregnant women in the UK is potentially cost saving. This finding has implications for the 1.88 billion people in the 32 countries with iodine deficiency worldwide. Valuation of IQ points should consider non-earnings benefits, e.g. health benefits associated with a higher IQ not germane to earnings".
This economic modelling study predicted that giving iodine supplements to pregnant women would save the NHS money and benefit the infant and wider society by boosting their intelligence.
The study has based its analysis on the UK perspective, used systematic searches and expert input to inform the likely health and economic effects of iodine supplementation.
A strong point of the study, as the authors say, is that they used a conservative approach. This meant they limited the possible benefits of iodine supplementation while overestimating the potential harms as much as possible. This suggests that the cost benefits and IQ gains may even be greater.
However, it is important to realise that these predictions are only as reliable as the studies that contributed data – which will never be perfect. For example, information on how iodine deficiency in pregnancy affected IQ loss in the child came from only three observational studies. These could be affected by a range of bias and confounding factors limiting their reliability. This means that predictions about the exact number of IQ points that have been potentially lost by iodine deficiency in the mother could contain some error. Similarly, it is possible that the savings in terms of cost to health and society are not completely accurate. That said, it’s probably the best they could have done with the available data.
For an individual pregnant woman reading this research in the media, cost savings to society are likely to be of limited relevance. Her concern will be for the health of her child and herself. From that perspective, the main point of interest is the assertion that it may increase the child’s IQ by 1.22 IQ points – though this would probably only be if you were iodine-deficient in the first place. You then have to balance this against the potential risks – mainly in terms of iodine function.
You should be able to get all the iodine you need from a healthy, balanced diet. Rich sources include fish and shellfish (though pregnant women need to take care when eating certain types of fish). Eggs, dairy and certain grains are other sources.
There is no current recommendation in the UK to take iodine supplements in pregnancy. It is not known whether this will change in the future. This economic evaluation would need to be considered as a whole alongside other research related to the harms and benefits of supplements.
In the meantime, if you are going to take iodine supplements, it is advised to take no more than 0.5mg a day, as taking more could be harmful.
Links To The Headlines
Iodine supplements for pregnant women could boost IQ and save NHS thousands. The Daily Telegraph, August 10 2015
Pregnancy iodine pills 'good for babies and economy'. BBC News, August 10 2015
Iodine supplements during pregnancy could save the state money, says new research. The Independent, August 10 2015
Links To Science
Monahan M, Boelaert K, Jolly K, et al. Costs and benefits of iodine supplementation for pregnant women in a mildly to moderately iodine-deficient population: a modelling analysis. The Lancet – Diabetes & Endocrinology. Published online August 9 2015
"White bread and pasta 'may increase the risk of depression'," reports the Mail Online today.
It doesn’t take much to realise that feeling down from time to time is probably not caused by the last cheese sarnie or bowl of spag bol you ate. But in this case, the news outlet is reporting on a well-conducted study of post-menopausal women’s diets and their depressive symptoms over time.
While the research did find a significant link between symptoms of depression and high dietary glycaemic index (GI) and glycaemic load, it can’t prove an inevitable cause and effect. The study also found that depression symptoms were particularly high in women who were less physically active, had a higher BMI, consumed more fatty foods, and less fruit and vegetables.
The relationship between diet and lifestyle, and other physical and mental health symptoms and conditions is complex, and it is not easy to single out direct effects.
Basic advice on a healthy diet includes a significant amount of starchy food, so do not be put off your morning toast by this news. Find out about the five steps to mental wellbeing if you want to know which activities, such as learning and exercise, may improve how you feel.
Where did the story come from?
The study was carried out by researchers from Columbia University, Stony Brook University, University of California-Davis, New York University Langone Medical Center, Duke University Medical Center and the University of Minnesota, all in the US. It was funded by the US National Heart, Lung, and Blood Institute.
The study was published in the peer-reviewed medical journal The American Journal of Clinical Nutrition.
Overall, the UK media reported the story accurately, but the study's limitations were not fully explained.
The Mail Online reported a quote from one of the researchers, Dr James Gangwisch, of Columbia University: "This suggests that dietary interventions could serve as treatments and preventive measures for depression." He added that, "Further study is needed to examine the potential of this novel option for treatment and prevention, and to see if similar results are found in the broader population."
The lack of clarity over whether a high-GI diet directly causes depression, or whether there could be some reverse association, or the involvement of other factors, makes it difficult to say whether such interventions could show promise.
What kind of research was this?
This was an longitudinal cohort study looking at the association between dietary GI and glycaemic load, and the prevalence and incidence of depression in post-menopausal women.
Researchers say that previous studies have shown positive association between consumption of sweetened beverages, processed foods (such as sweetened desserts and processed meats), and processed pastries (muffins, doughnuts, croissants and other commercial baked goods) and the risk of developing depression.
This was a longitudinal cohort study, so data was collected from the same people repeatedly over time. These studies can have variable length of follow-up to look at both short- or long-term impacts of an exposure (such as diet). One of the main drawbacks of this type of study design is that they do not fully explain whether the exposure (e.g. diet) causes the effects seen. Randomised controlled trials (RCTs) are a better way to understand the causal link, but RCTs on dietary links with health conditions trials can be unfeasible and unethical.
What did the research involve?
This study included 69,954 socioeconomically and racially/ethnically diverse post-menopausal women aged 50-79 years from 40 medical centres across the US between September 1994 and December 1998, as part of the Women’s Health Initiative.
Women with symptoms of depression at the time of recruitment – as assessed by the eight-item questionnaire used in the study – were excluded. Data was collected on characteristics such as education level, presence of health conditions and smoking status.
The women completed a 145-item food frequency questionnaire at the start of the study. This questionnaire was designed to work out the women’s intake of carbohydrate and dietary fibre and specific foods (whole grains, vegetables, nuts, seeds and legumes). This was then used to calculate GI and glycaemic load. The researchers analysed women’s diets in five groups or "quintiles", based on the levels of GI in their diets.
Depression symptoms after three years of follow-up were measured using the same Burnam eight-item scale for depressive disorders that was given at the study’s start.
Researchers used statistical methods to examine the relationship between GI and glycaemic load and depression symptoms at follow-up.
What were the basic results?
At the start of the study, women with higher GI quintiles tended to:
- be younger
- have higher BMI
- do less physical activity
- eat more fatty foods
- eat less fruit, vegetables, legumes, nuts, seeds and dietary fibre
They were also more likely to be black, have lower education, lower income, high blood pressure, and have previously had a heart attack. They were less likely to be on hormone replacement therapy, but more likely to smoke and have had stressful life events, and they were less likely to have good social support.
After three years, women who consumed more dietary added sugars were significantly more likely to experience symptoms of depression (odds ratio (OR) for the highest GI compared with lowest intake, 1.23, 95% confidence interval (CI) 1.07 to 1.41). Those who consumed a higher GI were also significantly more likely to experience depression symptoms (OR for the highest compared with lowest intake, 1.22, 95% CI 1.09 to 1.37).
Eating more dietary fibre and fruits and vegetables was associated with decreased odds for depression symptoms.How did the researchers interpret the results?
Researchers concluded that, "The results from this study suggest that high-GI diets could be a risk factor for depression in post-menopausal women."
They added that, "Randomised trials should be undertaken to examine the question of whether diets rich in low-GI foods, such as legumes, cereals high in viscous sticky fibres, and temperate-climate fruit, could serve as treatments and primary preventive measures for depression in post-menopausal women."
This observational study has found that over three years of follow-up, post-menopausal women who consumed a high-GI diet and larger amounts of dietary sugar were more likely to have depression symptoms three years later.
They study has several strengths, including a large sample size, a socioeconomically and racially/ethnically mixed population, and a relatively long follow-up period of up to three years.
However, this observational study cannot prove that a high-GI diet directly causes depression. Other limitations include its observational nature, meaning that it couldn’t weed out all the factors that might have influenced the link. It is not easy to single out direct causative effects, or completely exclude the influence of all other factors without conducting an RCT.
It’s also worth pointing out that the women reported their own diets, which allows for potentially inaccurate reporting. Also, the study used a brief questionnaire to assess depression symptoms, but didn't examine diagnoses of depression. It is also possible that this short scale could not have fully assessed all mental health symptoms that a person may have had at the time of study enrolment.
Finally, the results are only relevant to post-menopausal women (as they were the only people it looked at) and cannot be generalised to men nor to pre-menopausal women.
Overall, this study explores the possible links between eating habits and the risk of depression symptoms, but it can’t provide any firm answers.
We all recognise the link between what we eat and how we feel (for example, through so-called comfort eating). NHS Choices has a range of advice on getting a balanced diet, including information on starchy foods, as well as a series of audio guides to boost your mood.
Links To The Headlines
Links To Science
Gangwisch JE, et al. High glycemic index diet as a risk factor for depression: analyses from the Women’s Health Initiative. American Journal of Clinical Nutrition. Published June 24 2015
"The pill cuts womb cancer cases by 200,000," the Sky News website reports, in an uncommon example of a credible headline figure. However, it should be noted that it refers to the amount of cases prevented over 10 years.
The news follows a reliable review that found the longer women took the pill, the lower their risk of womb cancer. As demonstrated in the Sky News headline, the risk reductions were quite large – using the pill for about 10 to 15 years halved the risk of womb cancer (sometimes known as uterine or endometrial cancer). This effect lasted up to 30 years after oral contraception had stopped.
Researchers pooled the results of 36 studies including more than 140,000 women. It aimed to compare past use of combined oral contraceptives – aka the pill – in women with and without womb cancer. The results are not relevant to the progesterone-only "mini-pill".
The results showed that protection from womb cancer was the same for women taking the pill during the 1960s, 70s and 80s, even though earlier pills contained much higher oestrogen levels.
This finding isn’t new – the pill was already recognised to reduce risk of womb cancer, but this study has pooled the evidence to show just how big the link may be.
Cancer of the womb is relatively common and abnormal vaginal bleeding is the most common symptom.
There are a range of contraceptives on offer, not just hormonal pills. Each has its own pros and cons, and if you’re using contraception you should probably consider which might be the best contraceptive method for you.
Where did the story come from?
The study was carried out by a large group of researchers called the Collaborative Group on Epidemiological Studies on Endometrial Cancer and was funded by the Medical Research Council and Cancer Research UK.
The study was published in the peer-reviewed medical journal The Lancet Oncology.
The Guardian, Sky News and Mail Online all reported the study facts accurately. All reported that every five years of taking the pill reduced the chance of womb cancer by a quarter, and that this probably prevented about 200,000 cancer cases in the past decade.
The Guardian headline said: "Regularly taking the pill 'helps prevent two forms of cancer' decades after use". This refers to the current study on womb cancer as well as a study published in 2008 that found similar effects of the pill on the risk of ovarian cancer.
What kind of research was this?
Cancer of the womb (uterus) is a common cancer. Abnormal vaginal bleeding is the most common symptom of womb cancer. Read more about womb cancer.
The combined oral contraceptive pill – commonly called the pill – is already known to reduce the risk of endometrial cancer, but it is unclear how long this effect lasts after contraception is stopped, or whether it is modified by other factors like smoking or body weight.
A meta-analysis is a great way to investigate this issue. It pooled the results of many studies to find an overall result. By pooling lots of data, the reliability of the end result increases. This method relies on finding different studies investigating a similar issue in a similar way; otherwise, pooling the results isn’t a good idea.
What did the research involve?
The researchers pooled data from 36 studies that comprised a total of 27,276 women with endometrial cancer (cases) and 115,743 without (controls). They were looking for any statistically significant links between oral contraceptive use and cancer cases up to 30 years later.
The research team searched medical databases to identify studies measuring oral contraception use and endometrial cancer. This included contacting study authors for unpublished data.
Cases were defined as women with invasive cancer of any part of the uterus who were without previous cancer. The controls were women without previous cancer who had an intact uterus.
Most studies reported whether or not women had ever used hormonal contraceptives and most also provided information about the total duration of use and age or calendar year at first and last use.
Only 13 studies collected information on the type of hormonal contraceptives. Women from the remaining 23 studies were assumed to be using combined oral contraceptives, containing both oestrogen and progestogen, because more than 95% of hormonal contraceptive users included in studies with such information reported using combined preparations.
The analysis took into account any of the women’s factors known to affect cancer risk in an attempt to isolate the effect of oral contraceptives. These included their:
- number of births
- body mass index
- smoking habits
- use of hormone replacement therapy (HRT)
The researchers weren’t able to analyse women with endometrial cancer who had used exclusively progestogen-only oral contraceptives (sometimes called the "mini pill"), or sequential oral contraceptives (where separate pills contain oestrogen only or combined with progestogen 41 cases). This is because there were too few of these cases to do thorough analyses.
What were the basic results?
The average age of women with endometrial cancer (cases) in the study was 63. The researchers found 35% of cases reported using oral contraception in the past (for an average of three years), and 39% of controls had taken the pill (average 4.4 years’ use).
The longer the women used oral contraception, the more it reduced the risk of endometrial cancer. For example, for every five years women used contraception, the risk of endometrial cancer reduced by 24% (risk ratio (RR) 0.76, 95% confidence interval (CI) 0.73 to 0.78). This means that about 10 to 15 years of using the pill should halved the risk of endometrial cancer.
This reduction in risk persisted for more than 30 years after oral contraceptive use had stopped, with no apparent difference in risk between pills taken during the 1960s, 1970s, and 1980s, despite higher oestrogen doses in pills used in the early years.
There were some interesting subtleties in the results; particularly, the reduction in risk associated with ever having used oral contraceptives differed according to the type of cancer. There was a reduced risk for carcinomas – cancers of the lining of the uterus or womb (RR 0·69, 95% CI 0·66 to 0·71), but no significant effect on risk of sarcomas – cancers affecting the muscle or supporting tissue around the womb (RR 0·83, 95% CI 0·67 to 1·04).
In high-income countries such as the UK, 10 years use of oral contraceptives was estimated to reduce the absolute risk of endometrial cancer arising before age 75 years from 2.3 per 1,000 women to 1.3 per 100 women.
How did the researchers interpret the results?
The researchers said: "Use of oral contraceptives confers long-term protection against endometrial cancer. These results suggest that, in developed countries, about 400,000 cases of endometrial cancer before the age of 75 years have been prevented over the past 50 years (1965-2014) by oral contraceptives, including 200,000 in the past decade (2005-14)."
This review found that the longer women had taken the combined oral contraceptive pill (the pill) the greater their reduction in risk of endometrial cancer. The risk reductions were quite large – use for about 10 to 15 years halved the risk – and lasted up to 30 years after oral contraption had stopped.
The protection did not seem to depend much on the dose of oestrogen in the contraceptive formulations or on personal characteristics of the women, such as how many children they had given birth to, their body mass index or whether they were menopausal.
The study was large and is likely to have included most of the studies on the topic. The analysis was also reliable, creating precise risk estimates over long periods of time. These points all increase our confidence in the findings.
No research is without limitations, and in this case the analysis was only as reliable as the studies included. For example, not all studies had complete and detailed information on oral contraceptive use for all women. However, if this had an effect on the result, it probably wasn’t large.
The researchers say that the pill used by women in the 1960s would generally have contained much higher doses of oestrogen than those of the 1980s. Despite this, they didn’t find any differences in the risk reductions between the years. They interpreted this to mean that: "the amount of oestrogen in the lower-dose pills is still sufficient to reduce the incidence of endometrial cancer, which is consistent with findings from two studies that have assessed individual dosages of the hormonal constituents".
The pill is not without risks and is not suitable for all women. There is well-known risk of blood clots and some women may be at higher risk, such as smokers, those who are overweight or obese, and those with migraine or existing heart or vascular conditions. They have also been linked to increased risk of breast and cervical cancer.
Prof Valerie Beral, lead author of the study, explained the implications of the research to The Guardian: "There is an increase in cancer of the breast and cervix, but it is really quite small and they don’t persist." The Guardian itself added: "Once a woman stops taking the pill, her increased chances of breast or cervical cancer quickly disappear."
There are a range of hormonal and non-hormonal contraceptive methods on offer, not just oral pills, each with their own pros and cons. Find out which is best for you by following our contraception guide.
Links To The Headlines
Regularly taking the pill 'helps prevent two forms of cancer' decades after use. The Guardian. August 5 2015
The Pill Cuts Womb Cancer Cases By 200,000. Sky News. August 5 2015
The Pill could protect against womb cancer for five decades: Women who use drug for five years in their twenties can reduce chance of disease in their sixties and seventies by a quarter. Mail Online. August 5 2015
Links To Science
Collaborative Group on Epidemiological Studies on Endometrial Cancer. Endometrial cancer and oral contraceptives: an individual participant meta-analysis of 27 276 women with endometrial cancer from 36 epidemiological studies. The Lancet Oncology. Published August 4 2015
"Eating food rich in vitamins and minerals keeps the brain younger," reports the Daily Express. The headline was prompted by a US study of a new diet called MIND, which appeared to slow down ageing of the brain.
The MIND diet was developed specifically to help improve brain function and reduce dementia, and is a combination of the Mediterranean diet and the blood pressure-lowering DASH diet.
Both of these diets have previously shown positive effects on cognitive decline. The researchers wanted to see if they could narrow down which elements were the most important.
An earlier study of the MIND diet found participants who stuck rigorously to the diet were 52% less likely to be diagnosed with Alzheimer's disease.
The MIND diet involves eating "brain-healthy" foods, with particular emphasis on eating berries, such as blueberries, and green leafy vegetables, like spinach.
Unlike DASH and Mediterranean diets, MIND does not require eating lots of fruit, dairy or potatoes, or eating more than one fish meal a week.
Among the MIND diet components are 10 "brain-healthy" foods:
- green leafy vegetables, such as spinach and kale
- other vegetables, such as red peppers, squash, carrots and broccoli
- berries, including blueberries and strawberries
- beans, lentils and soybeans
- olive oil
- wine (in moderation)
And five unhealthy foods:
- red meats
- butter and stick margarine
- pastries and sweets
- fried or fast food
Some 960 participants, with an average age of over 80, without dementia completed food questionnaires and brain function tests each year for an average of five years.
The study found those who stuck closely to the MIND diet had brains about eight years younger than those in the study who didn't.
While these results are encouraging, this type of study can only show an association between diet and improved brain function – it cannot prove causation. Even so, the study does lend weight to the potential benefits of eating this type of diet.
Dr Clare Walton, of the Alzheimer's Society, told the Mail Online: "Previous research suggests that the MIND diet can reduce the risk of developing dementia, and now we see it could also slow down the cognitive decline normally seen with age."
"It's important that people realise there are several steps you can take to reduce your risk of dementia, in addition to a healthy balanced diet, including being physically and mentally active and not smoking."Where did the story come from?
The study was carried out by researchers from Rush University Medical Center in Chicago, and Harvard School of Public Health in Boston. It was funded by the National Institute on Aging.
The study was published in the peer-reviewed medical journal Alzheimer's and Dementia.
In general, the media reported the story accurately, but the study's limitations were not fully explained.What kind of research was this?
This was an observational study that aimed to investigate the relationship between a diet called MIND and its protective properties for cognitive decline seen with ageing.
The MIND diet is a combination of the Mediterranean and DASH (designed to lower blood pressure) diets. Researchers say both diets have shown positive effects in delaying the decline in brain function in previously conducted randomised control trials.
A number of other studies have also observed slower decline in mental abilities with high consumption of vegetables and green leafy vegetables.What did the research involve?
Older adults from Chicago were assessed annually between February 2004 and 2013 in terms of their diet and cognitive abilities. This comprised 960 residents of more than 40 retirement communities and senior public housing units. Their average age was 81.4 years, and 75% were female. Though the study spanned nine years, the average follow-up was 4.7 years.
The study participants did not have dementia at the time of enrolment into the trial and individuals with known dementia were excluded from the study.
Each participant underwent annual structured clinical evaluations and completed food frequency questionnaires, including total energy intake. The diets were scored according to how closely they followed the MIND diet.
Brain function testing was performed using 21 tests, 19 of which summarised ability in five areas:
- episodic memory – a type of long-term memory of specific events, situations and experiences
- working memory – short-term memory associated with reasoning, comprehension and learning
- semantic memory – long-term memory that processes ideas and concepts not drawn from personal experience
- visuospatial ability – ability to understand and process shapes and distances when performing specific tasks
- perceptual speed – ability to quickly and accurately compare letters, numbers, objects, pictures or patterns
Researchers also collected information on age, smoking history, weekly physical activity, mood, BMI, hypertension history and diabetes.
Lastly, they used statistical methods to assess the relationship between the MIND diet and brain function score.What were the basic results?
Higher MIND diet scores were associated with slower mental decline. This was true for all five mental tests, particularly for episodic memory, semantic memory and perceptual speed.
People with MIND diet scores in the top third had a slower decline than those in the bottom third, which was equivalent to being 7.5 years younger.
The results remained significant when potential outside factors (known as confounding factors) were taken into account, including hypertension, heart attack, stroke and diabetes.How did the researchers interpret the results?
The researchers concluded that, "Higher MIND diet score was associated with slower decline in cognitive abilities". They said that, "The MIND diet was based on the dietary components of the Mediterranean and DASH diets, including emphasis on natural plant-based foods, and limited intake of animal and high saturated fat foods.
"However, the MIND diet uniquely specifies consumption of berries and green leafy vegetables, and does not specify high fruit consumption (both DASH and Mediterranean), high dairy (DASH), high potato consumption, or more than one fish meal per week (Mediterranean)."Conclusion
This observational study aimed to investigate the relationship between the MIND diet and its protective properties for mental decline in an older population.
The study has several strengths, including the large sample size, long observational period of up to nine years, regular annual assessment of cognitive functions, and comprehensive assessment of diet.
However, one of the main limitations is that this type of study cannot show cause and effect – it can only show an association between the diet and slower mental decline. There may be other unmeasured factors that account for the results, such as genetics, other medical conditions or medication.
It also relies on self-reported estimates of dietary intake, so there is a chance for recall and reporting bias. Also, the study population at the time of enrolment was free of dementia, so we do not know how this diet would work in people with, or at increased risk of, dementia.
Overall, the study does lend weight to following the principles of this type of diet. Find out more about reducing the risk of dementia.
Links To The Headlines
Diet to beat dementia: Eating food rich in vitamins and minerals keeps the brain younger. Daily Express, August 6 2015
Diet high in leafy green vegetables may slow cognitive decline in elderly – study. The Guardian, August 5 2015
Links To Science
Morris MC, Tangney CC, Wang Y et al. MIND diet slows cognitive decline with aging. Alzheimer's & Dementia. Published online June 15 2015
"Curry really could be the spice of life," says The Daily Telegraph, reporting on a study looking at the link between regularly eating foods that contain capsaicin – found in chilli peppers – and the risk of dying early.
The study of nearly 500,000 people in China found those who ate spicy food once a week or more were about 10% less likely to die during the seven-year follow-up period than people who ate spicy food less than once a week.
However, the researchers say their work cannot prove that spicy food was behind the lower chance of death, and their work in China should not be taken to mean the same would be true elsewhere in the world.Where did the story come from?
The study was done by researchers from China (Peking University, the Chinese Academy of Medical Sciences, and five regional Centers for Disease Control and Prevention), the US (Harvard School of Public Health and Harvard Medical School), and the UK (the University of Oxford). It is part of the China Kadoorie Biobank study, an ongoing study of half a million adults from areas around China.
It was funded by grants from organisations including the National Natural Science Foundation of China, the Chinese Ministry of Science and Technology, the Wellcome Trust in the UK and the Kadoorie Charitable Foundation in Hong Kong.
The study was published in the peer-reviewed BMJ, and the research can be read for free on the BMJ website.
The story has been widely reported in the media, with newspapers such as the Mirror claiming that the research shows "curry helps you live longer" – but the study was carried out in China, so people were unlikely to have been eating curry.
The Mirror claims that, "people who ate spicy meals like curry favourites tikka masala, jalfrezi and vindaloo once or twice a week were less likely to die than those who had them less". The study did not look at consumption of Indian-style dishes such as vindaloo, but at how often Chinese people included chilli pepper or other spices in their diet.What kind of research was this?
This prospective observational study aimed to find a link between regularly eating chilli or other spices and how long people lived.
Observational studies are good at finding possible links between factors such as diet and health. However, they cannot prove that one factor causes another.What did the research involve?
Volunteers took a variety of tests and questionnaires relating to their health, family health, diet, exercise, income, tobacco and alcohol use, occupation and many other factors. They also answered a food frequency questionnaire, which asked how often they ate hot, spicy foods and what types of spices they used.
The researchers followed up the volunteers for an average of 7.2 years. They looked at whether people who eat chilli or other spices were more or less likely to have died during that time.
They adjusted their figures to take account of many factors we know affect length of life, such as smoking. They then calculated how likely people who ate spicy food regularly were to die, compared with people who ate spicy food less than once a week.What were the basic results?
The researchers looked at data from 199,293 men and 288,082 women. During the study period, 11,820 men and 8,404 women died. Compared with people who ate spicy food less than once a week, people who ate spicy food on one or two days were 10% less likely to have died during the study (hazard ratio [HR] 0.9, 95% confidence interval [CI] 0.84 to 0.96).
People who ate spicy food more than two days a week were about 14% less likely to have died during the study (HR 0.86, 95% CI 0.8 to 0.92) but the difference between eating spicy food once or twice a week and more often was small enough that it might be down to chance.
People who ate food containing fresh chilli pepper more than six times a week were less likely to die than those who ate dried chillies this frequently.
The researchers looked at the causes of death and found people who ate spicy food more often were less likely to die from cancer, heart disease or respiratory (lung) diseases. However, the amount of spicy food made little difference to the chances of dying from stroke, diabetes or infections.How did the researchers interpret the results?
The researchers said their results showed "significant inverse associations" between eating spicy food and dying of any cause or of some specific causes, meaning that people who ate spicy food were less likely to die of these causes.
They said the active ingredient in chilli pepper, capsaicin, has been shown to have a range of health-promoting effects, including antioxidant, anti-inflammatory and anti-cancer effects.
However, the researchers were cautious about their results. They said they could not conclude that spicy food protected against death, and that it is "essential" to carry out research in other groups of people outside China to be sure the results apply elsewhere.
They say further research could lead to evidence that will allow for updated guidelines on what people should eat for a healthy diet.Conclusion
This large, well-designed observational study adds to the evidence that certain spices such as chilli pepper may have a beneficial effect on health. But this study does have limitations that need to be taken into account.
The study found that people in China who ate a diet that included spicy food (mainly from chilli peppers) at least once a week were less likely to die during the study period than those who ate spicy food less often. These results applied to men and women, even after taking account of factors that affect the risk of death, such as age.
The study is part of an ongoing investigation into the effect many factors have on human health, including diet.
The amount of data collected on individuals, including detailed information about their regular diet, activity levels, occupation, family health history and other factors, means the researchers have a better chance of finding an effect from specific factors in the diet.
Also, the size of the study means the researchers have enough data to show clear trends, with less likelihood the results are down to chance alone.
However, even with the amount of detail collected about people in the study, we cannot be sure other factors did not have an effect. For example, we don't know how people cooked the chilli peppers, so we don't know whether they may have used more or less cooking oil, or other spices, or ate more rice or other carbohydrates to "dampen down" the effect of the hot chilli.
Additionally, the diet frequency questionnaire was only completed once, at the beginning of the study, and people's diets can change over time.
The lifestyles of people in rural China are likely to be very different from the urban populations of the UK or US. Eating some of the same foods may not have the same results if lots of other things about your life are different. The type of spicy food eaten by people in China, with different cooking techniques, may be very different from the sort of spicy foods eaten in the UK.
The study also found that drinking alcohol may reduce any positive effects of eating chilli peppers. The link between reduced chances of death and eating spicy food was weaker in people who also drank alcohol. The habit of drinking beer with curry in the UK may undermine any good news on chilli pepper.
Overall, this study adds to emerging evidence that capsaicin in chilli pepper may have a positive effect. We now need to see studies in populations outside China to be sure the findings apply to the rest of the world.
Links To The Headlines
Curries are good for you: Spicy foods can protect against premature death, study claims. Daily Express, August 4 2015
Why three curries a week could lower risk of death. The Daily Telegraph, August 4 2015
Spicy food 'can lower the risk of early death'. The Independent, August 5 2015
Links To Science
Jun Lv, Lu Qi, Canqing Yu et al. Consumption of spicy foods and total and cause specific mortality: population based cohort study. British Medical Journal. Published online August 4 2015
Going for a 15-minute walk every day will "make you live longer", reports the Mail Online. It is one of several news outlets to report that small amounts of daily exercise may be enough to increase your chances of living longer.
A study found people aged 60 and over who did just 15 minutes of exercise a day reduced their risk of dying early by 22%, compared with those of a similar age who did no exercise at all.
To stay healthy or improve health, UK guidelines advise all adults do at least 150 minutes of moderate physical activity a week. But many older people fail to meet this target.
The authors of the study found 75 minutes of activity a week appeared to be beneficial. They concluded that lowering the activity target could encourage more adults to take up physical activity.
However, they acknowledge that the more exercise people do, the lower their risk of ill health and early death.
Their findings were based on the results of nine studies involving more than 120,000 people, who were followed up for an average of 10 years.
They found regular exercise reduced the risk of an early death, even if people did less than the recommended amount of 150 minutes. The overall results suggest any physical activity is a good thing, even if recommended targets cannot be met.
But it is premature to say "exercise targets should be cut", as in The Daily Telegraph. The evidence has limitations, especially the fact it was provided by pooling the results of observational studies.
This makes it difficult to know how much the reduced risk of dying is directly the result of how much physical activity we do. Further research is needed to explore the ideal amount of exercise for those aged over 60.
Older people are advised to do 150 minutes a week of moderate aerobic activity. This can be in 10 to 15-minute chunks of activities such as brisk walking, gardening, dancing or swimming. Doing some activity every day is better than doing nothing, and this is true at any age.Where did the story come from?
The study was carried out by researchers from the University Hospital of Saint-Etienne, the University of Lyon, the University Hospital of Dijon, the University of Burgundy, the Regional Centre for Cancer Prevention, and Jean Monnet University in France, and Geneva University Hospitals in Switzerland.
Funding sources were not described.
The study was published in the peer-reviewed British Journal of Sports Medicine.
This story has been reported widely in the media, providing recommendations and guidelines for better health and improved life expectancy.What kind of research was this?
This was a systematic review and meta-analysis that aimed to determine whether lower amounts of moderate to vigorous physical activity in those aged 60 and over reduced the risk of dying early. Adults over 60 are currently advised to do 150 minutes of physical activity a week, but it is recognised this may not always be met.
A systematic review is useful for identifying all relevant studies that have examined this question, and combines the results to draw overall conclusions on the direction of the effect. However, the strength of the findings depends on the quality of the trials included.What did the research involve?
Two literature databases (PubMed and Embase) were searched up to February 2015 for English language prospective cohort studies.
Eligible studies were required to have included people over the age of 60 and examined how the amount of physical activity was related to deaths from any cause during at least three years of follow-up.What were the basic results?
Nine studies were used, which included a total of 122,417 participants aged 60 years and above (73,745 women and 48,672 men). The average age of participants (from seven studies only) was 72.9 years, and they were followed up for an average of 9.8 years. Six of the studies came from the US, two were from the Pacific region, and one included an Asian population.
Researchers found doing small amounts of physical activity of less than 150 minutes a week reduced the risk of dying early by 22% compared with doing no activity at all (relative Risk [RR] = 0.78, 95% confidence interval [CI] 0.71 to 0.87). A significant difference was found with gender – reduction in mortality was 14% for men and 32% for women.
Following the recommended 150 minutes a week reduced mortality by 28% compared with inactive individuals (RR 0.72, 95% CI 0.65 to 0.80).
It appears the benefit of increased physical activity on reducing mortality grows with increased duration, as participants who exceeded the 150-minute recommendation had 35% reduced risk compared with inactive participants (RR 0.65, 95% CI 0.61 to 0.70).How did the researchers interpret the results?
The researchers concluded that physical activity "reduces all-cause mortality in older adults". They found the first few minutes of any exercise session were the most beneficial for health.
The researchers acknowledged that the more activity people do, the greater the health benefits. However, they observed health benefits even in those who did only 15 minutes a day.Conclusion
This systematic review and meta-analysis aimed to investigate whether doing less exercise than the recommended activity levels was still effective in reducing the risk of dying early among adults aged 60 or over.
The study found physical activity even below the recommended amount reduced mortality in this group. However, higher levels of physical activity were associated with an even lower risk of dying early.
This study has strengths in its systematic review methods, the fact it searched the literature for studies published over 20 years that assessed the effects of physical activity, and that it only included studies with good methodological quality.
However, the results are only as reliable as the studies included. Some limitations include the following:
- These were all observational studies. The researchers have used risk figures that have been adjusted for confounders. However, the confounders the nine individual studies have accounted for are not reported and are likely to have varied. Other health and lifestyle factors may influence both the amount of exercise a person takes and their mortality risk. For example, a person with health problems that increase their mortality risk may also be taking less exercise. Similarly, a person taking more exercise may also be following other healthy lifestyle habits, such as not smoking, drinking little alcohol, and eating a healthy, balanced diet. Overall, this makes it difficult to single out the direct effect the amount of physical activity has had on mortality risk.
- The overall sample size was large, but a large proportion of study participants came from two of the nine studies.
- Definitions of bouts of physical activity or "doses" may have differed.
- None of the studies were conducted in the UK, which may limit their usefulness for this population as ethnic, cultural and environmental influences may have an effect.
Many people in the UK are failing to meet the recommended levels of physical activity. This study suggests that even if you can't meet the recommended amount, some exercise is better than none at all.
However, because of the limitations of the review, more research would be needed to look into the ideal exercise level before recommending reducing amounts for older adults.
We know that taking regular exercise has many health benefits, so being as active as possible is always beneficial. Regular exercise can reduce the risk of numerous major illnesses, such as heart disease, stroke, diabetes and cancer.
Exercise may also have beneficial effects on general wellbeing and may have some effect on mental health, such as reducing stress levels and depression.
Links To The Headlines
Exercising for just 15 minutes a week can boost life expectancy, say scientists. Daily Express, August 3 2015
Over 60s exercise targets should be cut to 15 minutes a day, say health experts. The Daily Telegraph, August 3 2015
Fifteen minutes of exercise a day will help you live longer says study. Daily Mirror, August 4 2015
Links To Science
Even a low-dose of moderate-to-vigorous physical activity reduces mortality by 22% in adults aged ≥60 years: a systematic review and meta-analysis. British Journal of Sports Medicine. Published online August 3 2015
"Ebola vaccine is 'potential game-changer'," says BBC News, while the Daily Mail cites a "100% effective jab" for the disease. These headlines stem from early results of a trial investigating the effects of an Ebola vaccine during the most recent outbreak of the virus in west Africa.
Researchers gave the Ebola virus vaccine to thousands of people in Guinea who'd had close contact with an infected individual – a process called "ring vaccination". Half the sample were given the vaccine immediately, while the other half were given the vaccine after a delay of three weeks.
The early results, published in The Lancet and publicised by the World Health Organization (WHO), showed the vaccine had 100% effectiveness when given immediately. Nobody developed Ebola symptoms up to 10 days after being given the vaccine immediately after exposure. However, 16 cases in the delayed vaccination group developed symptoms (0.5%). Further analysis of the results is ongoing.
The vaccine is not currently licensed for use. The data on its effectiveness and safety will need to be reported and scrutinised before we know whether it could be licensed and widely adopted.
Researchers are now trying the vaccine in Ebola-affected Sierra Leone. Liberia is the only other country affected by the Ebola virus at the moment, according to government information on Ebola.What is Ebola?
Ebola is a serious viral infection that can often be fatal. It is spread by close contact with an infected person, particularly through blood and other bodily secretions. For example, someone caring for a person with the Ebola virus could get infected after changing wound dressings or bed pans.
The first symptoms of Ebola virus disease can start anywhere up to three weeks after being infected. Symptoms include fever, headache, sore throat, general fatigue and weakness, muscle pains, vomiting and diarrhoea.
Ebola can also cause internal bleeding, which may present as bruising, a rash, bleeding from the mouth or gums, or blood in the stool. Because of this, the infection is sometimes called Ebola haemorrhagic fever.
There is no specific treatment for Ebola and care is usually supportive – for example, providing intravenous fluids. The average death rate from Ebola is reported to be 50%, though this varies depending on the health and immunity of the person who has been affected. Prevention of Ebola has always been better than cure.
In 2014, the largest known Ebola outbreak in history began in west Africa, centring on Guinea, Liberia and Sierra Leone. There were also individual cases of healthcare workers infected in west Africa who then imported the virus into western countries. No licensed Ebola vaccines were available, but they have been under investigation.Why is the Ebola vaccine in the news?
Early results of a phase III trial of the VSV-EBOV vaccine have been published by the WHO, and have also been reported in The Lancet. Phase III means this trial is in one of the final stages of testing the effectiveness and safety of the vaccine in a large sample of people.
The vaccination trial began in Guinea in March 2015 and has involved giving the vaccine to 7,651 volunteers. These are the contacts of people who have been infected with the virus (family members, neighbours, colleagues and so on).
This technique of identifying an infected person, their contacts, and their contacts' contacts is called "ring vaccination". It is said to be based on the strategy used to eradicate smallpox.
Study co-author, John-Arne Røttingen, who is director of the Division of Infectious Disease Control at the Norwegian Institute of Public Health, says: "The premise is that by vaccinating all people who have come into contact with an infected person you create a protective 'ring' and stop the virus from spreading further."
An editorial in The Lancet accompanying the research says the ring vaccination process isn't easy, as it can be hard to identify the network of contacts of a particular person, particularly when family and friends can be in dispersed communities across the country.
Rather than comparing the vaccine with an inactive placebo, roughly half of the contacts in the trial (4,123) were given the vaccine immediately; the remainder (3,528) after a three-week delay.
The ring vaccination trial stopped recruiting in July 2015. Another trial is said to be being conducted in parallel with the trial of ring vaccination, involving vaccinating frontline workers caring for sick people.What are the early trial results?
The trial showed 100% effectiveness when given immediately, with no vaccinated cases having Ebola symptoms up to 10 days after the vaccine.
In the delayed vaccination group, there were 16 people who developed Ebola symptoms up to 10 days after infection, affecting 0.5% of those exposed who received delayed vaccination.
All of these cases developed symptoms within one week of exposure to the infected person. The overall vaccine effectiveness in all people who received it is estimated to be around 75%.
As the WHO statement says, better evidence is also needed on the vaccine's capacity to protect the whole population through what is called "herd immunity".
What this means is that if enough people in a population are vaccinated or immune against an infection, this confers protection on unvaccinated people, as there aren't enough people around to catch and spread the virus in the first place.
Side effects were examined up to 12 weeks after vaccination. There were 43 serious side effects reported, one of which was a serious fever attributed to the vaccine. This resolved spontaneously. Assessment of side effects is ongoing.What do the results mean at the moment?
The vaccine is not currently licensed for use. More data on its safety and effectiveness is needed before it can be licensed for widespread use, and it will only pass if the evidence is good enough.
However, The Lancet reports background preparation may already be under way for its introduction: "If the evidence proves sufficient for licensing, a Global Ebola Vaccine Implementation Team, also under WHO's leadership, has been preparing the ground for its introduction – creating guidelines for the vaccine's use, strategies for community engagement, and mechanisms to expand country capacity for the vaccine's distribution and delivery."
It is also not possible to say who would be eligible for the vaccine – for example, whether it would just be healthcare workers in affected areas, or those who are known to have come into contact with an infected person.
The news of the successful Ebola vaccine trials has received widespread welcome from scientists. You can read the experts' views on the Ebola vaccine on the Science Media Centre website.
Links To The Headlines
Ebola vaccine success offers hope after trial shows 100 per cent success rate. The Independent, July 31 2015
Ebola vaccine is 'potential game-changer'. BBC News, July 31 2015
Links To Science
Henao-Restrepo AM, et al. Efficacy and effectiveness of an rVSV-vectored vaccine expressing Ebola surface glycoprotein: interim results from the Guinea ring vaccination cluster-randomised trial. The Lancet. Published August 3 2015
An Ebola vaccine: first results and promising opportunities. The Lancet. Published August 3 2015
"HIV flushed out by cancer drug", BBC News reports. This headline was prompted by laboratory research showing the promising results of a cancer drug being used to treat HIV.
In the early stages of HIV infection, some of the virus effectively goes into hiding in so-called HIV "reservoirs". These viruses are not "active", so standard anti-HIV drug treatments do not kill them.
In this study, researchers found viruses in blood samples from people with HIV infection could be reactivated using a cancer drug. They believe this would mean the viruses could then be identified by standard drug treatments, and killed. The drug did not appear to be toxic to other blood cells, although it wasn't tested on living humans.
While these are promising results, the experiments are at an early stage and it is not known if it would be safe to use the drug in this way for people infected with HIV.
The drug is currently used on the skin to treat a condition called actinic keratoses, which makes it unclear what effects the drug would have if used internally.Where did the story come from?
The study was carried out by researchers from the University of California, the San Francisco Veterans Affairs Medical Center, and Williams College, all in the US.
It was jointly funded by the National Institute of Health, UC Davis Research Investments in Science and Engineering (RISE), the Brazilian Federal Agency, and the Swiss National Science Foundation. Researchers say the funding organisations had no role in the study design, data collection and analysis.
The study was published in the peer-reviewed medical journal PLoS Pathogens.
In general, the media reported the story accurately, but the study's limitations were not fully explained.
The BBC reported an interesting quote from one of the researchers, Dr Satya Dandekar, who said: "We are excited to have identified an outstanding candidate for HIV reactivation and eradication that is already approved and is being used in patients. This molecule has great potential to advance into translational and clinical studies."
But although the drug is being used on patients, it is currently just applied to the skin. The effects may be very different if the whole body is exposed to the drug, as would be required to locate hidden reservoirs of HIV.What kind of research was this?
This laboratory study aimed to assess whether a drug currently used to treat a skin condition could be used to reactivate the HIV virus.
Currently available forms of anti-retroviral therapy (ART) are effective in stopping HIV replication, but they do not eliminate "latent" reservoirs of the virus in people infected with HIV. Other studies suggest starting ART early may not prevent latent virus reservoirs forming, or eliminate them.
More recent studies have looked at how some compounds may disrupt the cell signalling pathways that allow HIV to become latent in someone infected with the virus.
Researchers say some of these compounds effectively induce latent HIV reactivation in laboratory settings. One of these compounds is ingenol-3-angelate (PEP005), which is currently approved for clinical use and is used to treat a skin condition called actinic keratoses. This can develop into skin cancer if left untreated.
In this type of study, using cells in a lab, treatments sometimes show positive results, but don't always prove effective in living humans.What did the research involve?
The research included a cell culture of latent HIV with "defective" genes. Researchers say this clone is widely used for HIV latency studies.
The researchers collected blood samples from 13 people who were infected with HIV and receiving ART – 12 of these had been on ART for more than three years.
All the individuals had had "suppressed" viral activity for more than six months. The researchers also collected cells from uninfected individuals to act as a control.
All the human and cultured cells were incubated, with compounds being tested for 24 or 72 hours to see whether the cells were dead or alive after the tests.
To determine the potential of PEP005, cells were treated with increasing concentrations of PEP005.What were the basic results?
PEP005 increased the reactivation of the cell culture of latent HIV. The effect was even greater when PEP005 was combined with other compounds that also activate latent HIV.
When PEP005 was tested on blood samples from people with HIV infection, it activated latent HIV-infected cells in most of the samples. Again, the effects were higher when PEP005 was used in combination with other compounds.
Researchers also assessed potential side effects of PEP005 and found no significant toxicity or side effects on other blood cells from these samples.How did the researchers interpret the results?
Researchers concluded that PEP005 "effectively reactivated HIV from latency in primary CD4+ T cells from HIV-infected individuals receiving ART", and a combination of this and another compound increased this reactivation. They say these results "represent a new group of lead compounds for combating HIV latency".Conclusion
This laboratory study found the cancer drug PEP005 may be able to activate latent HIV. This could mean conventional anti-HIV treatments should then be able to eradicate it.
The drug has so far only shown positive results in the laboratory setting and has not been tested on humans in this way. As such, it's too early to tell if this really will help people infected with HIV to be free of the virus for good.
While these are some positive results, the side effects of this drug in humans has not been fully explored.
There is currently no cure for HIV, but there are treatments that can delay the start of symptoms. The World Health Organization (WHO) reports there are 35 million people currently living with HIV globally. Even if effective treatments were available, it's wise to practice safer sex using barrier contraception.
Links To The Headlines
HIV flushed out by cancer drug. BBC News, July 31 2015
Links To Science
Jiang G, et al. Synergistic Reactivation of Latent HIV Expression by Ingenol-3-Angelate, PEP005, Targeted NF-kB Signaling in Combination with JQ1 Induced p-TEFb Activation. PLoS Pathogens. Published July 30 2015