The benefits and risks of alcohol consumption have been controversial for decades. Some studies have suggested that “moderate” amounts of alcohol have health benefits. In other words, people who drink a little alcohol for longer life might be doing themselves some good. Other experts maintain that even moderate alcohol consumption will shorten your life. Confusing? You bet! And it has only become more confounding recently. Headlines proclaim that no amount of alcohol consumption is good for you–or that drinking won’t kill you. One new meta-analysis of data suggests that even modest alcohol consumption can raise blood pressure a little bit, but its results are still a bit confusing.
Does Drinking Alcohol Raise Your Blood Pressure?
The investigators reviewed the results of seven studies involving over 19,000 participants (Hypertension, August 2023). The volunteers were from Japan, Korea and the United States, and the median follow-up was over 5 years. Those who consumed roughly one drink a day had higher systolic blood pressure at the end of the study. The increase was small, just a little more than one point (mm Hg). Those who consumed nearly 4 drinks daily had almost 5 points higher blood pressure at the end of the study, compared to tee totalers.
There were anomalies, however. Women and North Americans who consumed four drinks daily actually had slightly lower diastolic blood pressure at follow-up. (Diastolic blood pressure is the second, lower number. For example, in 120/80, 120 is systolic and 80 is diastolic.) We do not know how important a drop in diastolic blood pressure might be.
The authors could not explain this unexpected outcome. They call for further research to assess the impact of specific types of alcoholic beverages as well as the effect on women. In general, however, they suggest that the linear relationship between alcohol consumption and systolic blood pressure should discourage people from drinking any amount on a regular basis.
Will a Little Alcohol Reduce Stress Levels and Improve Longevity?
There is evidence that suggest drinking small amounts of alcohol might have benefits, though. A study published in the Journal of the American College of Cardiology (June 20, 2023) proposes that light to moderate alcohol consumption reduces the risk of major adverse cardiovascular events (MACE) by lowering stress levels. The investigators analyzed data from the Mass General Brigham Biobank.
There were over 53,000 participants. About 24,000 did not consume alcohol. 27,000 people were light to moderate alcohol consumers. These drinkers had fewer cardiovascular problems such as heart attacks and strokes.
Brain imaging studies suggested that one possible mechanism is reduced stress related activity in the brain because of alcohol consumption.
The authors conclude that:
“This study’s results suggest that the benefit of light/ moderate (vs none/minimal) alcohol consumption on CVD risk in part stems from its ability to attenuate stress-related neural network activity.”
As encouraging as this new research seems to be, there are contradictory data that challenge any suggestions that alcohol reduces the risks of cardiovascular disease.
Why We Can’t Count on Alcohol for Longer Life:
A systematic review of 107 trials triggered the latest rash of headlines on whether alcohol affects mortality (JAMA Network Open, March 31, 2023). This ambitious study covered 4.8 million people who had told scientists whether and how much they drank. To determine whether people who drink just a little on a regular basis have any health advantage, the researchers compared them to individuals defined as occasional drinkers, less than one drink a week.
As expected, this study confirmed previous research showing that habitual heavy drinkers are more likely to die prematurely. (This kicks in at lower levels of drinking for women than for men.) But what about the light-to-moderate drinkers? The analysis shows no reduction in premature mortality for people taking two drinks or less a day. On the other hand, at that level of alcohol consumption, people were also no more likely to die ahead of their time.
The scientists concluded:
“In this updated systematic review and meta-analysis, daily low or moderate alcohol intake was not significantly associated with all-cause mortality risk, while increased risk was evident at higher consumption levels, starting at lower levels for women than men.”
Needless to say, these investigators and most commentators warn people against drinking alcohol for the purpose of improving their health.
Previous Studies on Alcohol and Mortality:
To really understand the controversy, we should review an earlier study showing that drinking a little helped people with heart disease (BMC Medicine, July 27, 2021). Moreover, previous research spelled out how much alcohol is enough to be beneficial and how much is harmful (PLoS Medicine, June 19, 2018). The results might surprise you. First, though, the opposing perspectives.
Alcohol for Longer Life Proponents:
The Mayo Clinic reports on its website that moderate alcohol consumption can:
- “Reduce your risk of developing and dying from heart disease
- “Possibly reduce your risk of ischemic stroke (when the arteries to your brain become narrowed or blocked, causing severely reduced blood flow)
- “Possibly reduce your risk of diabetes”
The experts for the Mayo Clinic define “moderate” alcohol consumption as:
- One drink a day for women.
- Two drinks a day for men under 65 and one drink for older men
- A drink equals a 5-ounce glass of wine or a 12-ounce glass of beer. A drink of liquor equals 1.5 ounces.
Alcohol for Longer Life Opponents:
A systematic review and meta-analysis published in the Journal of Studies on Alcohol and Drugs (online, March 22, 2016) reports:
“Estimates of mortality risk from alcohol are significantly altered by study design and characteristics. Meta-analyses adjusting for these factors find that low-volume alcohol consumption has no net mortality benefit compared with lifetime abstention or occasional drinking. These findings have implications for public policy, the formulation of low-risk drinking guidelines, and future research on alcohol and health.”
Alcohol and Dementia?
The data regarding alcohol consumption and Alzheimer’s disease are, unfortunately, even more confusing. Some research suggests that alcohol consumption is bad for the brain.
Norwegian investigators reported (European Journal of Epidemiology, online, May 13, 2015):
“The present study finds that frequent alcohol consumption is associated with a higher dementia risk compared to infrequent alcohol consumption. The same pattern of associations is indicated for Alzheimer’s disease and for vascular dementia, but the latter results were not statistically significant.”
Other research suggests that moderate alcohol consumption may reduce the risk for dementia: (Neuropsychiatric Disease and Treatment, online, Aug. 11, 2011)
“We reviewed 143 papers that described the relationship between moderate drinking of alcohol and some aspect of cognition…Overall, light to moderate drinking does not appear to impair cognition in younger subjects and actually seems to reduce the risk of dementia and cognitive decline in older subjects.”
Bewildered? We don’t blame you. People who drink a lot clearly suffer from serious heart problems, strokes and cancer. They may also develop cognitive decline and possibly Alzheimer’s disease. On the other hand, light alcohol consumption may help the brain.
Research on Alcohol for Longer Life:
A meta-analysis of nearly 50,000 men and women from the UK suggested that light-to-moderate drinking could reduce the risk of heart attacks, strokes and death in people with diagnosed cardiovascular disease (BMC Medicine, July 27, 2021). Graphing survival against alcohol consumption gave a J-shaped curve, with the lowest risk at 7 g/day of alcohol. A standard drink–a 12-ounce beer or a glass of wine–contains 14 g. Consequently, people who took about half a drink a day achieved the benefits of alcohol for longer life. These data were obtained from the UK Biobank and health surveys from England and Scotland. However, a meta-analysis of a dozen other studies corroborated these conclusions.
Comparing Light and Heavy Alcohol Consumption:
The definition of light alcohol consumption vs. heavy alcohol consumption is critical to the understanding of the seeming confusion. A study published in PLOS Medicine (June 19, 2018) tracked roughly 100,000 people for nearly nine years. Light alcohol drinkers (defined as just one to three drinks a week) were less likely to develop cancer or die prematurely compared to abstainers or “heavy” drinkers. The scientists defined heavy drinkers as those who consumed two to three alcoholic beverages a day. Very heavy drinkers (more than three alcoholic beverages a day) were much more likely to get cancer or die during the study.
The authors concluded:
“The study supports a J-shaped association between alcohol and mortality in older adults, which remains after adjustment for cancer risk. The results indicate that intakes below 1 drink per day were associated with the lowest risk of death.”
The Bottom Line on Alcohol for Longer Life:
A idea of a J-shaped curve is fascinating. In practical terms, it means that people who never drink alcohol have a slightly higher risk of cancer and death than those who indulge occasionally. People who usually consume more than three drinks a day run a much bigger risk. Consequently, the sweet spot seems to be lower alcohol consumption than previously described, namely one to three drinks a week. The data from the UK Biobank study fall within that range, too.
