One thing is certain: Any potential health benefit of alcohol stops when drinking becomes heavy and chronic.

To drink or not to drink — the messages are mixed. Some studies show that moderate alcohol intake is good for our health, while others show that even an occasional alcoholic beverage is detrimental. How are you supposed to know what is best for your health?

One thing is certain: Any potential health benefit of alcohol stops when drinking becomes heavy and chronic. Moderate alcohol intake is defined by the 2015–2020 Dietary Guidelines for Americans as no more than one drink per day for women and no more than two drinks per day for men. It’s important that you know what constitutes “one drink.” In the United States, one drink is usually 12 ounces of beer, five ounces of wine, or one and a half ounces of hard liquor.

Possible health benefits of moderate alcohol intake include a decreased risk for heart disease and stroke. These cardiovascular benefits result from several effects of alcohol, including that it raises HDL, or “good,” cholesterol; it promotes relaxation, which in turn reduces blood pressure (although only temporarily); and it decreases the concentration of fibrinogen, a substance that contributes to blood clots. Another benefit is a reduced risk of diabetes, which is due to alcohol enhancing the cells’ uptake of blood sugar.

But before you start drinking, you need to know the hazards of alcohol consumption as well.

Alcohol is tough on the liver. It is the liver’s job to detoxify and remove the alcohol from the body. Unlike protein, carbs and fats, alcohol cannot be stored in the body, so the liver must break alcohol down into nutrients, such as fat and carbs, that the body can use or store. Drinking too much for the liver to process in a timely manner can lead to fatty liver disease. This disease develops to some extent in nearly everyone who drinks more than about two ounces of alcohol daily. Continued excess alcohol consumption can lead to cirrhosis, in which healthy tissue is replaced by scar tissue. Fatty liver can be reversible by abstaining from alcohol, but cirrhosis is irreversible and leads to liver failure.

Alcohol can cause harmful interactions with medications. Alcohol can change how your medications are metabolized. It might decrease their effectiveness, or it may make them toxic.

Alcohol causes sleep disturbances. While a nightcap might seem to make you fall asleep easily, the sedative effect wears off in the night resulting in more fragmented sleep. And because alcohol is a relaxant, sleep apnea is more pronounced. You are also more likely to have vivid dreams and nightmares.

Alcohol is the second-most energy-rich nutrient after fat, so the extra calories from alcohol often lead to weight gain, especially belly fat.

Alcohol is the leading cause of preventable birth defects.

Alcohol increases cancer risks, especially of the mouth, throat, esophagus, breast, colon and liver. If you smoke and drink, your risks are compounded.

Alcohol is addictive. Some people are predisposed to alcohol dependency; family history, social habits and mental health all play a role here. 

Alcohol can affect your immune system, making you more susceptible to infections.

Alcohol interferes with the brain’s communication pathways and can change mood and behavior, making it harder to think clearly. Studies also have shown links between heavy drinking and an increased risk of dementia. 

Whether you should drink alcohol depends on your age, sex, specific medical conditions, family history and risk factors. Pregnant women and those prone to dependency should not drink at all. If your risk for cancer is high, it’s probably not worth the risk to drink at all. If your risk for heart disease is high, you may benefit from an occasional alcoholic beverage. If you don’t currently drink, it’s not advisable to start because the benefits are likely small. 

The type of alcohol you drink is not as important as how much. Binge drinking, or saving up your daily drinks, is an unhealthy habit. Wine may have the nutritional edge on other alcoholic beverages because of its high concentration of antioxidants. Whatever you decide, stay within the recommended guidelines.

Anita Marlay, R.D., L.D., is a dietitian in the Cardiopulmonary Rehab department at Lake Regional Health System in Osage Beach, Mo.