Is There Any Amount of Alcohol That Is Good for You?
What the research really tells us about the dangers of drinking.
Posted Mar 05, 2021 | Reviewed by Devon Frye
- Drinking excessive amounts of alcohol is a well-established danger to physical health.
- The evidence on moderate levels of drinking, however, is mixed.
- Some research has concluded that moderate drinking confers benefits to heart health; on the other hand, some metabolites of alcohol are known carcinogens and alcohol consumption increases cancer risk.
- Increased alcohol consumption triggered by the coronavirus pandemic could have long-term consequences on physical health if left unchecked.
Many reports and studies tell us that Americans have been drinking more alcohol since the start of the coronavirus pandemic. As restrictions have been placed on bars and restaurants, online sales of alcoholic beverages have soared. Presumably, people are drinking more to blunt the stress and strain of the pandemic and its attendant social isolation and economic woes. Is this increase in drinking alcohol harmful?
Of course, no one disputes that excessive drinking to the point of meeting criteria for an alcohol use disorder is harmful. There are differences of opinion, however, about the health effects of more moderate alcohol consumption. Some studies have shown that moderate drinking, usually defined as one to two drinks a day for men and one drink a day for women, has beneficial effects on heart health. One potential reason for this is that alcohol raises the level of so-called “good” or HDL cholesterol. It also has an anticoagulant effect, which decreases blood clotting and therefore potentially reduces clot formation in the coronary arteries.
It is important to remember, however, that although studies do suggest fewer cardiovascular deaths in people who drink moderate amounts of alcohol, no study has ever shown for sure that this is a cause-and-effect relationship. It could be that people who drink a bit of red wine every day have other lifestyle advantages over those who do not, like better access to healthcare or more exercise. Furthermore, there are other ways to achieve similar benefits on cholesterol levels, including exercise and possibly consuming foods that contain the same antioxidant as red wine—resveratrol. Such foods include grapes and blueberries.
At the other end of the spectrum, more than moderate levels of alcohol consumption are likely to harm the heart. One study, for example, showed that several biomarkers in the blood of heavy drinkers were elevated compared to non-drinkers, indicating a pathological effect on the cardiovascular system. Somewhere in the transition from moderate to heavy drinking, alcohol loses its potential cardioprotective effect and becomes a cardiovascular toxin, capable of increasing the risk for high blood pressure, heart attack, and stroke.
The Connection Between Alcohol and Cancer Risk
So far, this seems to make the decision to drink fairly straightforward—one drink a day is OK, more than that may not be. But that is only considering alcohol’s effects on the cardiovascular system. Less well-known perhaps is the fact that some metabolites of alcohol are carcinogens, including acetaldehyde. Last year, the American Cancer Society, in its "Guideline for Diet and Physical Activity for Cancer Prevention," said “it is best not to drink alcohol.”
That statement doesn't suggest that it is OK to drink moderately, but rather you should not drink at all (the guidelines do say that if you are going to drink, drink moderately). The message here is that alcohol consumption is associated with increased risk for a number of different kinds of cancer, including head and neck cancer, esophageal cancer, liver cancer, breast cancer, and colorectal cancer. A recent epidemiological survey looked at the number of cancer cases and cancer deaths attributable to alcohol consumption. The numbers varied widely by state, but senior author Farhad Islami concluded from the work that “In the United States, on average, alcohol consumption accounts for 4.8 percent of cancer cases and 3.2 percent of cancer deaths." In some instances, the influence of alcohol was even greater, accounting for 12.1 percent of cases of breast cancer in women and more than a quarter of cases of throat cancer.
When dealing with carcinogens, it can be hard to put upper and lower limits on how much is safe and how much is likely to cause cancer. Smoking one cigarette a month is not as great a risk for lung cancer as smoking two packs a day. How much alcohol over a lifetime increases the risk for any of the alcohol-associated cancers is still unclear, which is likely why the American Cancer Society makes its blanket recommendation that “it is best not to drink alcohol” rather than telling us how much alcohol is likely to be unsafe.
Why Drinking More Now Could Hurt Us Later
All of this makes the increases in alcohol sales and consumption during this last year of the pandemic especially alarming. Perhaps if the pandemic ends soon we will see a drop in drinking, but there is no guarantee that that will happen; many of the people who started drinking or increased their drinking since March 2020 are likely to continue doing so even when the pandemic finally ends. If they drink at moderate levels—one to two drinks a day for men and one drink a day for women—they may actually reduce their risk for heart disease but at the same time increase their risk for cancer. If they drink heavily, then both heart disease and cancer risks go up.
Increased alcohol consumption could turn out to be one of the biggest long-term health risks of the pandemic. Public prevention efforts are urgently needed. At the same time, healthcare providers should make a special effort to inquire about patients’ drinking habits and warn them of the risks.