"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
“Cystic fibrosis hope as new gene therapy improves condition,” The Daily Telegraph reports. Researchers have, for the first time, managed to successfully "smuggle" healthy copies of genes into the lungs of people with cystic fibrosis.
Cystic fibrosis is a genetic condition caused by a mutated gene called CFTR. The mutation causes the lungs and digestive system to become clogged up with sticky mucus.
The goal of gene therapy for cystic fibrosis is to replace the faulty CFTR gene with a working one.
Previous attempts of using a virus to deliver the working gene proved unsuccessful, as the lungs’ defence system against infection stopped the virus from entering.
In this new study, the researchers tried a different approach – the gene was encased in a bubble of fat, which was then delivered to the lungs via a nebuliser.
When compared to placebo, the nebuliser-delivered approach showed a modest, but significant, improvement in lung function (3.7%).
A 3.7% improvement may not sound that impressive, but the exciting news is that the technique actually worked in a few of the study’s participants in the first place. It may be possible to enhance the technique in the future to boost lung function dramatically.
It is likely that larger and longer trials are now being planned.
Where did the story come from?
The study was carried out by researchers from University of Oxford and Imperial College London, and was jointly funded by the Cystic Fibrosis Trust, National Institute for Health Research (NIHR) Clinical Research Network, and Just Gene Therapy.
A number of the researchers have patents related to the gene therapy reported in the study and also declared links to pharmaceutical companies. The team state that the: “funder of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.”
This story was widely covered by UK media. Overall, the media reported the story accurately, but the limitations of the study were not fully explained.
BBC News published an important quote from one of the researchers involved in this study, Prof Eric Alton, of Imperial College London, who said: "The effect is modest and it is variable. It is not ready to go straight into the clinic yet."
What kind of research was this?
This was a randomised controlled trial (RCT) that aimed to assess the effectiveness of non-viral gene therapy compared with inactive placebo in people with cystic fibrosis. It was a phase 2b trial, meaning it was gathering information on effectiveness and safety, which will hopefully pave the way to larger phase 3 trials comparing the technique with existing treatments.
Cystic fibrosis is a genetic condition in which the lungs and digestive system become clogged with thick, sticky mucus. Symptoms of cystic fibrosis usually start in early childhood and include:
- a persistent cough
- recurring chest and lung infections
- poor weight gain
An early sign is that an affected child’s sweat is unusually salty, which can be noticeable when you kiss your child. However, most cases of cystic fibrosis in the UK are now identified through screening tests carried out early in life, before symptoms appear.
There is currently no cure for cystic fibrosis. Treatment options for cystic fibrosis include those that aim to control symptoms, such as physiotherapy (a range of exercises can clear mucus from the lungs) and bronchodilators (a type of medication that expands the airways, making it easier to breathe), and antibiotics to treat lung infections. In some cases, a lung transplant may eventually be required, if the lungs become extensively damaged.
Previous studies have tried to use viruses to deliver a functioning CFTR gene into the lungs, with limited success. This study used a non-virus based method to deliver the CFTR gene – encasing it in a bubble of fat – in the expectation this would be more successful.
RCTs are one of the best types of study design to determine whether a treatment is effective. Potential biases are reduced through randomisation. This study was also double blind, meaning that both patients and those assessing them were unaware of whether the person had received treatment or placebo.
What did the research involve?
A group of 140 people with cystic fibrosis were randomly assigned to either the gene treatment, which was given the name pGM169/GL67A (78 patients), or placebo (62 patients).
Patients received either 5ml of pGM169/GL67A (containing 13.3mg of plasmid DNA and 75mg of the GL67A lipid mixture), or 5ml of inactive saline (salt solution) through a nebuliser (a machine that converts the medicine to a mist, so it can be inhaled into the lungs).
Patients received either treatment or placebo at 28-day intervals (plus or minus 5 days) for 12 months. Patients in both groups also received an average of three courses of oral or intravenous antibiotics during the trial.
Patients recruited for this study were from 18 sites in the UK and were aged 12 years or older. Their lung function was measured using a standard test called forced expiratory volume in 1 second (FEV1). This measures the amount of air that can be forcibly exhaled in the first second after a maximal inspiration. To be included in the study, participants had to have an FEV1 of 50-90% of the normal level.
The main outcome of interest was the change in the percentage of predicted FEV1. Other outcomes examined were CT scans of the lungs, self-reported symptoms ratings and quality of life scores.
The main analysis was per-protocol. Per-protocol means that only people who took the medicine as planned were analysed. This excludes those who had dropped out for any reason. Intention to treat analysis is the more realistic scenario, as people might stop treatment in the real world. Per protocol analysis gives a good idea of whether the medicine works in those who took it as intended.
In this study, the per-protocol analysis included 116 people, 83% of those were randomised.
What were the basic results?
Researchers found that, overall, the treatment (pGM169/GL67A) significantly improved FEV1 by 3.7% compared with placebo at 12 months follow-up. This was described as a “modest” benefit to lung function and a statistically significant one.
The changes within each of the individual groups were an average reduction of 4.0% in the placebo group, compared with a 0.4% reduction in the pGM169/GL67A group. This means that lung function got a little worse in both groups over the year, but those in the placebo group deteriorated more. This led some headlines to report that the new drug was able to “stabilise” symptoms; that is, stopping them getting any worse, which was accurate.
There was no statistically significant difference between groups in adverse effects like fatigue and increased respiratory symptoms and flu-like symptoms. Overall, authors say that some patients responded to the new treatment better than the others.
Six serious adverse events, all in the pGM169/GL67A group, were recorded. But neither the Data Monitoring and Ethics Committee, nor the Trial Steering Committee involved in the research, regarded any serious adverse event as related to the study drug. One event was considered to be possibly related to a trial procedure (bronchoscopy).
How did the researchers interpret the results?
The researchers concluded that: “Although we are encouraged by the first demonstration of a significant beneficial effect in lung function compared with placebo associated with gene therapy in patients with cystic fibrosis, the mean difference was modest, only recorded in some individuals, and at the lower end of the range of results seen in clinical trials which result in changes in patient-related care.”
They added: “Further improvements in efficacy and consistency of response to the current formulation, or its combination with CFTR potentiators, are needed before gene therapy is suitable for clinical practice.”
This RCT showed that a new non-viral-based gene therapy for cystic fibrosis was able to produce “modest” benefits in lung function compared to a placebo. The treatments were given once a month for a year.
The study had many strengths, including its double-blind randomised design, recruiting adequate numbers to demonstrate real differences between groups, and using pre-specified outcomes and sub-analysis. This means we can be confident in the reliability of the findings presented.
Although the findings of this study are encouraging, there are always limitations.
- This study was relatively small, recruiting just 140 patients. This is normal for a phase II trial, but large clinical trials are needed to fully assess the effects and safety of this treatment in development.
- Patients recruited in this trial had to be clinically stable to be included. This means they might be at their optimum respiratory health at this stage. Therefore, we don’t know how the treatment would work in clinically unstable or very severe patient groups.
It is important to realise that both groups’ lung function got worse over the year, so the treatment as it stands is quite limited. The new gene therapy was able to lessen some of the deterioration, but not in all. Nonetheless, this gives the researchers hope and scope to work out how to improve it.
Optimising the dose, working out why it worked in some people and not others, and trialling the therapy in more people are the natural next steps in this treatment development.
This is very much a proof-of-concept study rather than a study that provides a viable treatment in itself. It is a breakthrough in the development of gene therapy treatment for cystic fibrosis, but there is a lot of refinement and experimentation needed before this could be a routinely available treatment.
Links To The Headlines
Cystic fibrosis hope as new gene therapy improves condition. The Daily Telegraph, July 3 2015
Gene therapy stabilises lungs of cystic fibrosis patients. BBC News, July 3 2015
Cystic fibrosis: Gene therapy offers hope to patients after successful trials. The Independent, July 3 2015
Cystic fibrosis: Gene therapy treatment for cystic fibrosis may be possible by 2020, scientists say. The Guardian, July 3 2015
Links To Science
Alton EWF, Armstrong DK, Ashby D, et al. Repeated nebulisation of non-viral CFTR gene therapy in patients with cystic fibrosis: a randomised, double-blind, placebo-controlled, phase 2b trial (PDF, 1.07Mb). The Lancet. Published online July 3 2015
Ok says Paddy Power ‘the left wing PC brigade gets their knickers in a twist but we can live with that’ as controversial ad is released
Paddy Power insisted their latest ad – which features a March firm’s lorry-, might “mean the left wing PC brigade gets their knickers in a twist but we can live with that”.
A collection will take place on Waterbeach village green next Saturday for Ely food bank.
East Cambridgeshire’s top young musicians were crowned at a special competition held at Soham Village College.
An Ely care home has issued some tips to help keep its residents safe in the heatwave.
The Independence Day celebrations at RAF Feltwell have been cancelled at the last minute due to security reasons.