Medical Compass: Does light to moderate drinking protect women’s health?
By David Dunaief, M.D.
What is one of the most widely consumed over-the-counter drugs? Would it surprise you to hear that it’s alcohol?
There are many myths surrounding alcohol consumption. For example, you may have heard that Europeans who drink wine regularly live longer because of this. Or that only heavy drinkers need to be concerned about the resulting long-term health impacts. Both have been studied extensively.
Let’s look at what the research shows.
What’s the relationship between alcohol and cancer risk?
Alcohol is listed as a known carcinogen by the National Toxicology Program of the US Department of Health and Human Services (1). Among the research it details, it lists head and neck, esophageal, breast, liver and colorectal cancers as key cancer risks that are increased by alcohol consumption. Of these, esophageal and breast cancer risks are increased with even light drinking.
The World Health Organization reports that the International Agency for Research on Cancer classified alcohol at the highest level of carcinogen, along with asbestos, radiation, and tobacco (2).
In a January 2023 New York Times interview with Marissa Esser from the Centers for Disease Control and Prevention, she explained: “When you drink alcohol, your body metabolizes it into acetaldehyde, a chemical that is toxic to cells. Acetaldehyde both ‘damages your DNA and prevents your body from repairing the damage.’” Damaged DNA allows cells to develop into cancer tumors (3).
A meta-analysis of European studies on the effects of light to moderate alcohol use, defined as no more than two standard drinks per day, found that this level of intake caused 23,000 new cancers in the European Union in 2017 (4). Female breast cancer accounted for almost half of these.
These results support an earlier meta-analysis of 113 studies, which found there was a four percent increased risk of breast cancer with daily alcohol consumption of one drink or fewer a day (5). The authors warned that women who are at high risk of breast cancer should not drink alcohol or should drink it only occasionally.
It was also shown in the Nurses’ Health Study that drinking three to six glasses a week increased the risk of breast cancer modestly over a 28-year period (6). This study involved over 100,000 women. Even a half-glass of alcohol was associated with a 15 percent elevated risk of invasive breast cancer. The risk was dose-dependent, meaning the more participants drank in a day, the greater their risk increase. In this study, there was no difference in risk by type of alcohol consumed, whether wine, beer or liquor.
Based on what we think we know, if you are going to drink, a drink a few times a week may have the least impact on breast cancer. According to an accompanying editorial, alcohol may work by increasing the levels of sex hormones, including estrogen, and we don’t know if stopping diminishes this effect (7).
Does alcohol affect stroke risk?
On the positive side, an analysis of over 83,000 women in the Nurses’ Health Study demonstrated a decrease in the risk of both ischemic (caused by clots) and hemorrhagic (caused by bleeding) strokes with low to moderate amounts of alcohol (8). Those who drank less than a half-glass of alcohol daily were 17 percent less likely than nondrinkers to experience a stroke. Those who consumed one-half to one-and-a-half glasses a day had a 23 percent decreased risk of stroke, compared to nondrinkers.
However, women who consumed more experienced a decline in benefits, and drinking three or more glasses daily resulted in a non-significant increased risk of stroke. The reasons for alcohol’s benefits in stroke have been postulated to involve an anti-platelet effect (preventing clots) and increasing HDL (“good”) cholesterol. Patients should not drink alcohol solely to get stroke protection benefits.
If you’re looking for another option to achieve the same benefits, an analysis of the Nurses’ Health Study recently showed that those who consumed more citrus fruits had approximately a 19 percent reduction in stroke risk (9). The citrus fruits used most often in this study were oranges and grapefruits. Note that grapefruit may interfere with medications such as Plavix (clopidogrel), a commonly used antiplatelet medication used to prevent strokes (10).
Where does this leave us?
Moderation is the key. It is important to remember that alcohol is a drug, and it does have side effects. The American Heart Association recommends that women drink no more than one glass of alcohol a day. Less is better.
For those at high risk of breast cancer, consider forgoing alcohol.
The stroke benefit is tiny, and in some studies, non-existent. Therefore, it’s better to err on the side of caution and minimize your intake.
If you choose to forgo alcohol, the good news is that there are many more appealing, non-alcoholic beverages on the market than there have been in the past.
References:
(1) cancer.gov. (2) who.int (3) nytimes.com (4) Eur J Public Health. Jun 2021;31(3):591-596. (5) Alc and Alcoholism. 2012;47(3)3:204–212. (6) JAMA. 2011;306:1884-1890. (7) JAMA. 2011;306(17):1920-1921. (8) Stroke. 2012;43:939–945. (9) Stroke. 2012;43:946–951. (10) Medscape.com.
Dr. David Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician.
