Previous research on alcohol consumption and heart disease has suggested that light drinking may be beneficial to the heart. However, a new study published in JAMA Network Open has shown that all levels of alcohol consumption (even very light drinking) are associated with an increased risk of cardiovascular disease.
The study used data from over 370,000 people in a UK biomedical database (the UK Biobank) to examine the relationship between alcohol consumption and cardiovascular disease risk. Like previous observational studies, the researchers saw that light-to-moderate drinkers (about 1–7 drinks per week) had the lowest risk of heart disease, while those who did not drink had the second-lowest risk. However, the researchers also looked at the overall lifestyles of the groups and found that light-to-moderate drinkers had healthier lifestyles than those who abstained, including more exercise, more vegetable intake, and less smoking. When these lifestyle factors were considered, the benefits for the light-to-moderate drinking group were completely negated; when controlled for lifestyle, light-to-moderate drinking increased the risk of cardiovascular disease compared to not drinking.
Another important result from this study was that the relationship between alcohol consumption and cardiovascular disease risk was not linear. While the increase in risk from zero to seven drinks per week was relatively small, risk increased substantially from seven to 14 drinks and even more from 14 to 21 drinks. Rather than a linear relationship, alcohol intake and heart disease risk appear to have an exponential relationship. This result, which is supported by previous analyses, suggests that cutting back on drinking will have the greatest benefits for the heaviest drinkers.
Despite previous research suggesting that light drinking may benefit the heart, this and other recent studies have shown that any level of drinking is likely harmful to the heart. Abstaining from drinking, along with eating a healthy diet, getting enough exercise, and not smoking, will optimally lower heart disease risk.
Sources: JAMA, Science Daily, Labroots