More and more scientific evidence shows that alcohol is bad for the heart. As Movendi International has reported, two recent studies illustrate that even low-dose alcohol use can increase the risk of atrial fibrillation (AF) episodes in AF patients and increase risk of a new diagnosis of AF among those who are not patients.
AF is a heart condition where patients suffer from irregular heartbeat. It is the most common heart arrhythmia seen clinically. AF causes loss of quality of life, significant health care costs, stroke and in the worst case death.
The study by Marcus and colleagues published in the Annals of Medicine found that among AF patients,
- One alcoholic beverage in the past four hours, increased the risk of an AF episode by two times, and
- Two or more alcoholic beverages in the past four hours, increased the risk of an AF episode by three times.
- AF episodes were also linked with higher blood alcohol concentration.
The study by Csengeri and colleagues published on the European Heart Journal analyzed alcohol’s health effects on 107,845 people aged 24 to 97 years from Sweden, Norway, Finland, Denmark and Italy followed through 14 years. They found that,
- the risk of developing the condition increased by 16% with 12g of alcohol a day compared to being alcohol-free. This is equivalent to 330ml of beer, 120ml of wine, or 40ml of spirits.
- The higher the alcohol intake the more the risk increased. With two alcohol beverages a day it increased to 28% and with four or more it increased to 47%.
Alcohol industry funding distorts science on alcohol and cardiovascular health
Given the new and growing scientific evidence proving alcohol’s negative effects on cardiovascular health, it is important to find out what kind of influence the alcohol industry has on research indicating cardio-protective effects of alcohol.
In a recent research analysis, Golder and McCambridge analyze the extent that alcohol industry funding affects reporting of cardio-protective effects of alcohol in systematic reviews on cardiovascular disease (CVD) and alcohol. The authors analyze systematic reviews since such reviews have a larger influence on subsequent policy changes than any individual study.
Key findings from the analysis are:
- Almost a quarter (23%, 14/60) of systematic reviews undertaken on the impact of alcohol on CVD were by authors with a known connection to alcohol industry funding including five reviews which were directly funded by the alcohol industry.
- All the reviews by authors with alcohol industry connections exclusively identified a health protective effect of alcohol. These formed distinct co-authorship subnetworks within the research literature.
- Those with no known history of alcohol industry support were approximately evenly divided regarding any health protective effect of alcohol.
- The reviews with industry funding were more likely to study broader outcomes such as ‘cardiovascular disease’ or ‘coronary heart disease’ as opposed to specific CVD issues such as hypertension or stroke.
- The reviews with industry connection included more studies, and were cited more by others.
- However, over time systematic reviews on CVD and alcohol undertaken by authors who had industry connections reduced while reviews by authors with no history of industry connection increased.
The findings of the study expose that alcohol industry funding or history of funding skewed the results of reviews in favor of the alcohol industry.
The authors state that this analysis could have missed research where alcohol industry connections were deliberately hidden such as in the case with the tobacco industry. It could also have missed conflicts of interest which were beyond the declaration period i.e. three years. Therefore, an even higher proportion of reviews which show health protective effects of alcohol may have been affected by the alcohol industry, but not discovered in this analysis.
Studying broader cardiovascular outcomes – as alcohol industry connected research reviews have done – could bias the reviews. Prof. Jürgen Rehm has suggested that selecting broad outcomes render reviews meaningless.
The authors of this analysis encourage further research regarding the issue of CVD and alcohol. Looking into the primary research evidence used in the studied reviews and their conflicts of interest can further illustrate the extent of alcohol industry influence in CVD and alcohol research.
Another recent study by Peake and colleagues published in the European Journal of Public Health found that alcohol industry funded health organizations mis-represent the evidence on cardiovascular effects of low dose (“moderate”) alcohol consumption.
This idea [that alcohol may be good for the heart] has been assiduously promoted by the alcohol industry for whom it looks clearly important to political strategies. This study demonstrates that there is a need not only to resolve the long running controversy, but also to pay attention to the actions of the alcohol industry in influencing the science,” conclude Su Golder and Jim McCambridge, the authors of the research analysis on alcohol, cardiovascular disease and industry funding, as per Science Direct.
Su Golder and Jim McCambridge, the authors of this research analysis
