"Seven alcoholic drinks a week can help to prevent heart disease," the Daily Mirror reports. A US study suggests alcohol consumption up to this level may have a protective effect against heart failure.
This large US study followed more than 14,000 adults aged 45 and older for 24 years. It found those who drank up to 12 UK units (7 standard US "drinks") per week at the start of the study had a lower risk of developing heart failure than those who never drank alcohol.
The average alcohol consumption in this lower risk group was about 5 UK units a week (around 2.5 low-strength ABV 3.6% pints of lager a week).
At this level of consumption, men were 20% less likely to develop heart failure compared with people who never drank, while for women it was 16%.
The study benefits from its large size and the fact data was collected over a long period of time.
But studying the impact of alcohol on outcomes is fraught with difficulty. These difficulties include people not all having the same idea of what a "drink" or "unit" is.
People may also intentionally misreport their alcohol intake. We also cannot be certain alcohol intake alone is giving rise to the reduction in risk seen.
Steps you can take to help reduce your risk of heart failure – and other types of heart disease – include eating a healthy diet, achieving and maintaining a healthy weight, and quitting smoking (if you smoke).
Where did the story come from?
The study was carried out by researchers from Brigham and Women's Hospital in Boston, and other research centres in the US, the UK and Portugal.
It was published in the peer-reviewed European Heart Journal.
The UK media generally did not translate the measure of "drinks" used in this study into UK units, which people might have found easier to understand.
The standard US "drink" in this study contained 14g of alcohol, and a UK unit is 8g of alcohol. So the group with the reduced risk actually drank up to 12 units a week.
The reporting also makes it seem as though 12 units – what is referred to in the papers as "a glass a day" – is the optimal level, but the study cannot not tell us this.
While consumption in this lower risk group was "up to" 12 units per week, the average consumption was about 5 units per week. This is about 3.5 small glasses (125ml of 12% alcohol by volume) of wine a week, not a "glass a day".
And the poor old Daily Express got itself into a right muddle. At the time of writing, its website is actually running two versions of the story.
One story claims moderate alcohol consumption was linked to reduced heart failure risk, which is accurate.
What kind of research was this?
This was a large prospective cohort study looking at the relationship between alcohol consumption and the risk of heart failure.
Heavy alcohol consumption is known to increase the risk of heart failure, but the researchers say the effects of moderate alcohol consumption are not clear.
This type of study is the best way to look at the link between alcohol consumption and health outcomes, as it would not be feasible (or arguably ethical) to randomise people to consume different amounts of alcohol over a long period of time.
As with all observational studies, other factors (confounders) may be having an effect on the outcome, and it is difficult to be certain their impact has been entirely removed.
Studying the effects of alcohol intake is notoriously difficult for a range of reasons. Not least is what can be termed the "Del Boy effect": in one episode of the comedy Only Fools and Horses, the lead character tells his GP he is a teetotal fitness fanatic when in fact the opposite is true – people often misrepresent how healthy they are when talking to their doctor.
What did the research involve?
The researchers recruited adults (average age 54 years) who did not have heart failure in 1987 to 1989, and followed them up over about 24 years.
Researchers assessed the participants' alcohol consumption at the start of and during the study, and identified any participants who developed heart failure.
They then compared the likelihood of developing heart failure among people with different levels of alcohol intake.
Participants came from four communities in the US, and were aged 45 to 64 years old at the start of the study. The current analyses only included black or white participants. People with evidence of heart failure at the start of the study were excluded.
The participants had annual telephone calls with researchers, and in-person visits every three years.
At each interview, participants were asked if they currently drank alcohol and, if not, whether they had done so in the past. Those who drank were asked how often they usually drank wine, beer, or spirits (hard liquor).
It was not clear exactly how participants were asked to quantify their drinking, but the researchers used the information collected to determine how many standard drinks each person consumed a week.
A drink in this study was considered to be 14g of alcohol. In the UK, 1 unit is 8g of pure alcohol, so this drink would be 1.75 units in UK terms.
People developing heart failure were identified by looking at hospital records and national death records. This identified those recorded as being hospitalised for, or dying from, heart failure.
For their analyses, the researchers grouped people according to their alcohol consumption at the start of the study, and looked at whether their risk of heart failure differed across the groups.
They repeated their analyses using people's average alcohol consumption over the first nine years of the study.
The researchers took into account potential confounders at the start of the study, including:
- health conditions, including high blood pressure, diabetes, coronary artery disease, stroke and heart attack
- cholesterol levels
- body mass index (BMI)
- physical activity level
- educational level (as an indication of socioeconomic status)
What were the basic results?
Among the participants:
- 42% never drank alcohol
- 19% were former alcohol drinkers who had stopped
- 25% reported drinking up to 7 drinks (up to 12.25 UK units) per week (average consumption in this group was about 3 drinks per week, or 5.25 UK units)
- 8% reported drinking 7 to 14 drinks (12.25 to 24.5 UK units) per week
- 3% reported drinking 14 to 21 drinks (24.5 to 36.75 UK units) per week
- 3% reported drinking 21 drinks or more (36.75 UK units or more) per week
People in the various alcohol consumption categories differed from each other in a variety of ways. For example, heavier drinkers tended to be younger and have lower BMIs, but be more likely to smoke.
Overall, about 17% of participants were hospitalised for, or died from, heart failure during the 24 years of the study.
Men who drank up to 7 drinks per week at the start of the study were 20% less likely to develop heart failure than those who never drank alcohol (hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.68 to 0.94).
Women who drank up to 7 drinks per week at the start of the study were 16% less likely to develop heart failure than those who never drank alcohol (HR 0.84, 95% CI 0.71 to 1.00).
But at the upper level of the confidence interval (1.00), there would be no actual difference in risk reduction.
People who drank 7 drinks a week or more did not differ significantly in their risk of heart failure compared with those who never drank alcohol.
Those who drank the most (21 drinks per week or more for men, and those drinking 14 drinks per week or more for women) were more likely to die from any cause during the study.
How did the researchers interpret the results?
The researchers concluded that, "Alcohol consumption of up to 7 drinks [about 12 UK units] per week at early middle age is associated with lower risk for future HF [heart failure], with a similar but less definite association in women than in men."
This study suggests drinking up to about 12 UK units a week is associated with a lower risk of heart failure in men compared with never drinking alcohol.
There was a similar result for women, but the results were not as robust and did not rule out the possibility of there being no difference.
The study benefits from its large size (more than 14,000 people) and the fact it collected its data prospectively over a long period of time.
However, studying the impact of alcohol on outcomes is fraught with difficulty. These difficulties include people not being entirely sure what a "drink" or a "unit" is, and reporting their intakes incorrectly as a result.
In addition, people may intentionally misreport their alcohol intake – for example, if they are concerned about what the researchers will think about their intake.
Also, people who do not drink may do so for reasons linked to their health, so may have a greater risk of being unhealthy.
Other limitations are that while the researchers did try to take a number of confounders into account, unmeasured factors could still be having an effect, such as diet.
For example, these confounders were only assessed at the start of the study, and people may have changed over the study period (such as taking up smoking).
The study only identified people who were hospitalised for, or died from, heart failure. This misses people who had not yet been hospitalised or died from the condition.
The results also may not apply to younger people, and the researchers could not look at specific patterns of drinking, such as binge drinking.
Although no level of alcohol intake was associated with an increased risk of heart failure in this study, the authors note few people drank very heavily in their sample. Excessive alcohol consumption is known to lead to heart damage.
The study also did not look at the incidence of other alcohol-related illnesses, such as liver disease. Deaths from liver disease in the UK have increased 400% since 1970, due in part to increased alcohol consumption, as we discussed in November 2014.
The NHS recommends that:
- men should not regularly drink more than 3-4 units of alcohol a day
- women should not regularly drink more than 2-3 units a day
- if you've had a heavy drinking session, avoid alcohol for 48 hours
Here, "regularly" means drinking this amount every day or most days of the week.
The amount of alcohol consumed in the study group with the reduced risk was within the UK's recommended maximum consumption limits.
But it is generally not recommended that people take up drinking alcohol just for any potential heart benefits. If you do drink alcohol, you should stick within the recommended limits.
Links To The Headlines
Seven alcoholic drinks a week can help to prevent heart disease, new research reveals. Daily Mirror, January 20 2015
A drink a day 'cuts heart disease risk by a fifth' researchers claim...so don't worry about having a dry January. Mail Online, January 19 2015
A drink a night 'is better for your heart than none at all'. The Independent, January 19 2015
Glass of wine a day could protect the heart. The Daily Telegraph, January 20 2015
Daily drink 'cuts risk' of middle-age heart failure. The Times, January 20 2015
Drinking half a pint of beer a day could fight heart failure. Daily Express, January 20 2015
Links To Science
Gonçalves A, Claggett B, Jhund PS, et al. Alcohol consumption and risk of heart failure: the Atherosclerosis Risk in Communities Study. European Heart Journal. Published online January 20 2015
"Very fit men in their late 40s are less likely to get lung cancer and colorectal cancer than unfit men," says BBC News as it reports on a new US study.
The study involved a comprehensive fitness test of 13,949 US men. They were split into three fitness groups: lowest 20%, middle 40% and top 40%, and followed for an average of 6.5 years to see if fitness affected their chance of developing certain cancers.
Perhaps surprisingly, men in the top group actually had a 22% higher risk of prostate cancer.
One obvious point is that men who exercise to stay fit are usually healthy in other ways too, such as eating a healthy diet and abstaining from alcohol. This could have influenced the results.
Still, there is evidence that exercise alone can reduce your cancer risk. Information provided by Cancer Research UK explains how exercise can reduce inflammation and prevent bowel damage, which may reduce cancer risk.
With its proven effect of preventing heart disease, regular exercise is always a good idea, whatever your age or sex. Read more about the benefits of exercise.Where did the story come from?
The study was carried out by researchers from the University of Vermont, the University of Texas Southwestern Medical Center, Duke University Medical Center in Dallas, and the Memorial Sloan Kettering Cancer Center in New York.
It was funded by the US National Institute of General Medical Sciences, the National Institutes of Health, and the National Cancer Institute.
Generally, the UK media reported the story accurately, but none mentioned the possibility that diet could be accounting for some of the improvements seen, not just fitness.What kind of research was this?
This was a longitudinal study looking at whether cardiorespiratory fitness (having both a healthy heart and lungs) prevents or improves outcomes in cancer.
It used data already collected as part of the long-running Cooper Center Longitudinal study.
There are many risk factors for cancer, including age, diet and physical activity. This study focused on fitness and whether this helped men develop fewer cancers, and survive better if they did develop cancer.What did the research involve?
The research analysed fitness data on 13,949 US men collected as part of the Cooper Center Longitudinal study between 1971 and 2009.
The men were split into three fitness groups: lowest 20%, middle 40% and top 40%, and followed for an average of 6.5 years to see if fitness levels affected their chance of developing lung, colorectal or prostate cancer.
Fitness was assessed using an incremental treadmill test, which tests a person's ability to run to exhaustion.
The outcomes researchers were most interested in studying were:
- new cases of prostate, lung and colorectal cancer
- death from any cause for men developing cancer over the age of 65
- cause-specific death, such as cardiovascular disease, for men developing cancer over the age of 65
Cancer diagnosis and notification of death came from Medicare claims data, which is the US government health insurance system covering people over 65.
The statistical analysis took account of many common cancer risk factors, but not diet or the stage of cancer at diagnosis.
The confounding factors adjusted for included:
- examination year
- body mass index (BMI)
- total cholesterol level
- systolic blood pressure
- diabetes mellitus
- fasting glucose level
Over the study period, 181 men were diagnosed with colon cancers, 200 with lung cancers, and 1,310 with prostate cancers.
The main message from the results is that exercise is very good at reducing the risk of developing lung and colorectal cancer, as well as helping reduce the risk of dying from cancer or cardiovascular disease. The pattern of risk for prostate cancer was less clear.
Men in the fittest group were 55% less likely to develop lung cancer (hazard ratio [HR] 0.45; 95% confidence interval [CI], 0.29 to 0.68), and 46% less likely to develop colorectal cancer (HR, 0.56; 95%; CI, 0.36 to 0.87), compared with men in the lowest fitness group. The risk of prostate cancer was actually 22% higher (HR 1.22; 95%; CI, 1.02 to 1.46).
Similar benefits were seen comparing the middle exercise group with the lowest exercise group, but the risk differences were slightly smaller.
For example, risks were 43% lower for lung cancer and 33% lower for colon cancer compared with the lowest fitness group. This time there was no difference for prostate cancer. This analysis covered cancers diagnosed at any age.
Looking only at cancers diagnosed after the age of 65, the fittest group were 32% less likely to die from cancer compared with men in the lowest fitness group (HR, 0.68; 95%; CI, 0.47 to 0.98) – this included prostate cancer.
They were also 68% less likely to die from cardiovascular disease after a cancer diagnosis (HR, 0.32; 95%; CI, 0.16 to 0.64) compared with the least fit men.How did the researchers interpret the results?
The authors concluded that, "There is an inverse association between midlife CRF [cardiorespiratory fitness] and incident lung and colorectal cancer, but not prostate cancer. High midlife CRF is associated with lower risk of cause-specific mortality in those diagnosed as having cancer at Medicare age [over 65]."Conclusion
This study shows that cardiovascular fitness is likely to reduce men's chances of developing lung and colorectal cancer, and appears to boost survival from cancer or cardiovascular disease in those diagnosed after the age of 65. This was based on comparing the top 40% of fittest men with the 20% least fit.
The study focused on fitness and took account of major risk factors for cancer, such as smoking and blood pressure. However, it left out one important risk factor: diet. What people eat and drink is known to affect cancer risk.
The fittest group may also have been the healthiest in terms of eating well and drinking alcohol within safe limits. This probably accounted for some of the risk reductions seen in this study. What proportion? We don't know.
This, in effect, makes this a study of healthiness incorporating fitness and diet. The evidence that eating well and being active reduces the risk of cancer, heart disease, stroke and diabetes is already well established. Studies have also shown regular physical activity also benefits our mental health.
Read more about reducing your cancer risk.
Although fitter men over the age of 65 diagnosed with cancer had better survival rates, there are other unmeasured factors that could have contributed. It is not known whether the fitter people were diagnosed with cancer at an earlier stage, which would have increased their chance of survival.
There was also a counterintuitive finding worth noting. The fittest group were more likely to be diagnosed with prostate cancer than the least fit. This is important, as prostate cancer risk was much higher than lung or colon cancer in the sample.
The study authors thought this might be because fitter men go for more cancer tests in the US than unfit men, so therefore the cancer is discovered and diagnosed more often in that group.
It could also be the case that men in the fittest group would probably live longer, and prostate cancer is an age-related disease.
But we don't know this for sure, and there could be other explanations worth investigating.
Would you know if you had prostate cancer? Read more about prostate cancer symptoms.
Links To The Headlines
Fit middle-aged men 'at lower risk for some cancers'. BBC News, March 27 2015
Keep fit to beat cancer: Looking after yourself in middle age boosts men's chances. Daily Mirror, March 27 2015
Keeping fit helps men with cancer to boost survival chances by a third. The Times, March 27 2015
Links To Science
Lakoski SG, Willis BL, Barlow CE, et al. Midlife Cardiorespiratory Fitness, Incident Cancer, and Survival After Cancer in Men - The Cooper Center Longitudinal Study. JAMA Oncology. Published March 26 2015
"Crossing your fingers might reduce pain," says The Guardian. The study behind the news found crossing your fingers may confuse the way your brain processes feelings of hot and cold – and, in some cases, reduce painful sensations.
Rather than subjecting the participants to "normal" pain, the authors used a trick known as the thermal grill illusion. The thermal grill illusion is not the latest in BBQ technology, but an unusual – and well validated – phantom pain effect.
When the skin is subjected to an alternating pattern of harmless coldness followed by heat, it creates a sensation of "burning coldness", but does no damage to the skin. It is something akin to the burning sensation felt by anyone placing cold hands under warm water after a snowball fight.
The researchers applied hot and cold sensations to the ring, middle and index fingers to create phantom pain sensations in volunteers. The phantom pain reduced in some people when they crossed their fingers.
This artificial phantom set-up means the findings probably don't apply to most real-life experiences of pain. Would a woman crossing her fingers during childbirth feel some benefit, or would someone who has just hit their thumb with a hammer? Probably not.
We shouldn't get too hung up on the crossed finger idea, though. The concept behind it is more interesting. The study tentatively showed that pain might be influenced by how our bodies are organised in space and relative inputs from different parts of your body.
If it is found to be a regular and real occurrence through more research, this may have potential for use in pain management in healthcare.Where did the story come from?
The study was carried out by researchers from University College London (UCL) and the University of Verona (Italy).
It was funded by the CooperInt Program from the University of Verona, the European Union Seventh Framework Programme, the Economic and Social Research Council, and the European Research Council.
The study was published in the peer-reviewed science journal Current Biology.
The Guardian reported the story accurately, making it clear it was not real-world pain, but phantom pain from the thermal grill illusion.
The paper interviewed Elisa Ferrè of UCL and a co-author, who said: "There might be applications for treating people with chronic pain … the position of your limbs or digits is something that would be very easy to manipulate."
Adding a welcome note of caution, The Guardian wrote: "The findings did not establish whether crossing your fingers would be as soothing with a real painful stimulus, rather than an illusory one, but Ferrè said her hunch is that it would help."What kind of research was this?
This was a study of human volunteers investigating whether pain perception is influenced by the position of their fingers.
Rather than subjecting the participants to conventional pain, the team used a trick known as the thermal grill illusion to create a phantom pain sensation.
Controlled experiments such as these are useful for developing new ideas and testing them in the early stages. But testing pain in an indirect manner like this isn't ideal. It would be more useful to devise a test using actual pain, but this has ethical dimensions to consider.What did the research involve?
The researchers used three heat pads under the index, middle and ring fingers of participants to test different combinations of the thermal grill illusion, and whether crossing fingers reduced the phantom pain.
Participants also adjusted a temperature delivered to the other hand until it matched their perception of the cold target finger (index or middle).
The thermal grill illusion works by applying a warm sensation to the index and ring fingers, and a cold sensation to the middle finger. The grill-like pattern of warm-cold-warm creates a burning sensation in the middle finger, even though it is in fact exposed to cold.
About half of people go as far as describing the feeling as painful. The sensation is much more intense than the hot or cold on their own.
According to the researchers, the illusion might work because the hot sensation in the outer two fingers blocks the activity in a certain cooling receptor under the skin. With this pathway blocked, the hot signals from the nearby hot areas are felt more intensely.What were the basic results?
The study found significant temperature overestimation when the target finger was in the middle (warm-cold-warm) compared with on the end (cold-warm-warm).
The effect depended on the target finger being in the middle of thermal inputs, but it didn't matter whether this was the index or middle target fingers.
The thermal grill effect for the middle finger was abolished when it was crossed over the index. The same effect was generated for the index finger when it was crossed with the middle.How did the researchers interpret the results?
The team concluded that, "Our results suggest that the locations of multiple stimuli are remapped into external space as a group; nociceptively mediated sensations [pain perception] depended not on the body posture, but rather on the external spatial configuration formed by the pattern of thermal stimuli in each posture."Conclusion
This study investigated pain using a thermal grill trick, which applies hot and cold in different combinations to the index, middle and ring fingers to induce a phantom burning sensation.
This showed that crossing your fingers may confuse the way your brain processes feelings of hot and cold, and in some cases stopped the phantom pain.
The biggest limitation of this study is that it looked at phantom pain using the thermal grill trick, rather than actual pain. Phantom pain may be different from "normal" pain, so the results may not relate to a regular pain situation.
We shouldn't get too hung up on the crossed finger idea, though. The concept behind it is more interesting. The study tentatively showed that pain might be influenced by how our bodies are organised in space, and relative inputs from different parts of your body.
If found to be a regular and real occurrence through more research, this may have potential for use in pain management in healthcare.
For example, The Guardian says: "Scientists believe the phenomenon could ultimately be harnessed to help treat chronic pain patients, who suffer from painful sensations, often long after a physical injury has healed."
At present, this is largely speculative. The study only showed reduction in phantom pain, and only under a very specific and artificial set of circumstances. Research that is more relevant and applicable to real life would be the logical next step for this research field.
Still, how we think about pain can sometimes alter how it much it affects us. Many people find cognitive behavioural therapy (CBT) techniques can be useful in helping people cope better with chronic pain.
Read more about coping with pain.
Links To The Headlines
Crossing your fingers might reduce pain, says study. The Guardian, March 26 2015
Crossing your fingers actually DOES help – just not the way you expect. Metro, March 26 2015
Links To Science
Marotta A, Ferrè ER, Haggard P. Transforming the Thermal Grill Effect by Crossing the Fingers. Current Biology. Published online March 26 2015