Replacing bar meetups with virtual happy hours might offer a much-needed salve during the novel coronavirus pandemic, but downing too much alcohol could also reduce your immune system’s ability to fight off infectious diseases, according to numerous studies.

The bottom line: A glass of wine seems fine, but repeated rounds—especially of hard liquor—or increased alcohol use over days or weeks might suppress immune responses or lead to a greater susceptibility to pneumonia. (Pneumonia has developed in cases of moderate-to-severe COVID-19, the illness caused by the novel coronavirus.)

And while COVID-19 mortality rates are highest among the elderly, younger people are at risk of complications, too: Nearly 40% of those hospitalized with COVID-19 in the US were ages 20 to 54, and more than half in that range fell between ages 20 and 44, preliminary CDC data show (echoing similar earlier findings in China).

As social distancing sets in, loneliness and depression might also increase, raising the specter of wider alcohol use—especially if variations of shelter-in-place last for weeks or months. Chronic drinkers should pay extra attention, and so should their loved ones, especially during layoffs or lost jobs, said Paul Sasha Nestadt, MD, codirector of the Johns Hopkins Anxiety Disorders Clinic. “There are risk factors with isolation, the lack of a schedule, and if alcohol is just there in the house with you,” noted Nestadt. “People with depression, anxiety, and substance abuse are also at higher risk when stressed.”

Partiers who order booze for home delivery or gather in groups, especially longtime drinkers, should be wary and consider experts’ precautions. “Clinicians have long observed an association between excessive alcohol consumption and adverse immune-related effects such as susceptibility to pneumonia,” noted a 2015 article, Alcohol and The Immune System, published in Alcohol Research: Current Reviews. “Alcohol disrupts immune pathways in complex and seemingly paradoxical ways.”

Various studies indicate that alcohol use can deliver a body blow: It messes with humans' gastrointestinal system, altering the function of healthy gut microbes linked to immunity. Alcohol can also impair key immune cells in the lungs and damage epithelial cells that line the lungs' surface (where COVID-19 can also attack). ”Often, the alcohol-provoked lung damage goes undetected until a second insult, such as a respiratory infection, leads to more severe lung diseases,” the article noted. “Alcohol consumption does not have to be chronic to have negative health consequences. In fact, research shows that acute binge drinking also affects the immune system.”

A night of bingeing might dampen immunity, lasting into the next day or possibly longer, studies suggest. “In general, alcohol in the system at the time of exposure to a pathogen impairs [a person’s] innate immunity,” said Kathy Jung, PhD, a coauthor of the study and director of the National Institute on Alcohol Abuse and Alcoholism’s division of Metabolism and Health Effects. “So, it is easier to catch a cold during binge drinking episodes.”

Majid Afshar, MD, an assistant professor at Loyola University Health Systems in Illinois, has studied binge drinking’s effects on the immune system.

Such drinking can disrupt the body’s “ability to mount an adequate immune response to a stressful situation, such as impeding a healthy response to the coronavirus,” Afshar said. 4 or 5 drinks or more can impair signaling proteins known as cytokines, “important fighters” in the immune system’s cellular arsenal.

What about all the images of coronapocalypse parties and crowded beach scenes?

“Younger people need to remember alcohol is a toxin and try to minimize that toxin,” Afshar added. Drinking may be an “integral part of social culture, but let’s try to do it in moderation.”

The good news: Most people don’t need to avoid drinking altogether. Other studies suggest that imbibing “light to moderate amounts of polyphenol-rich alcoholic beverages like wine or beer” might not negatively impede immunity and could offer cardiovascular or other health benefits. One caveat, as noted in a 2007 article in the British Journal of Nutrition: “drinking patterns, beverage type, amount of alcohol, or gender differences [women metabolize alcohol differently] will affect the influence that alcohol consumption may have on the immune system.”

The NIAAA advises those who do drink to drink moderately: No more than 2 drinks per day for men and 1 drink for women.

As overall uncertainty spreads along with the novel coronavirus, curbside recycling bins in your neighborhood may overflow with empty bottles and beer cans. Any wider health impacts for populations might depend on how long the pandemic and related stress continues. “We know that stressors of all kinds can increase the likelihood of relapse for those with an alcohol use disorder and an escalation in drinking for those without one,” Jung added. “At a population level, alcohol use increases in times of turmoil, whether from 9/11, Hurricane Katrina, earthquakes, or other unexpected stressful events. We are living in a world that might remain socially fractured for much longer than in previous disasters. This has people in the addiction field concerned.”

Keeping tabs on each other by old-school phone calls or online or social media support groups (see the NIAAA Treatment Navigator for a short list of programs) might help mitigate alcohol or substance overuse and related health concerns, as private struggles could be masked by stay-at-home advisories.

Adds Nestadt, also an assistant professor of Psychiatry and Behavioral Sciences at Johns Hopkins: “One way to identify depression in loved ones is knowing whether they are isolating themselves and coming out less. And here we are all isolating, as we should be, but this means we must be extra vigilant.”

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