Most people know the feeling of waking up feeling sick after drinking a bit too much. While that feeling will go away within a day or two, regular drinking can impair your immune system, leading to more frequent infections and illnesses. In addition to being hungover, you are more likely to get the flu as well. There are several reasons this happens.
Alcohol suppresses your immune system. White blood cells are your body’s main way of fighting infection. Alcohol actually reduces your white blood cell count, making you more vulnerable to infection. Whether it’s a virus or an untreated cut, pathogens will meet less resistance and therefore be more dangerous.
White blood cells also protect against cancer. Cancer starts out as a few aberrant cells. Normally, these cells are destroyed by white blood cells and never become a problem. But if your white blood cell count is low because of heavy drinking, the problem cells have a better chance of becoming cancer. An increased risk of cancer is a lesser known danger of excessive drinking.
Excessive drinking leads to malnutrition. Any sort of addiction can lead to bad eating habits. Opioids or stimulants can make you eat too little, marijuana can make you eat too much, and whatever your drug of choice, you will likely end up going for food that’s cheap and convenient rather than healthy. Poor eating habits can lead to malnutrition, but alcohol poses an additional problem. Even if you eat reasonably healthy food, excessive drinking prevents nutrients from being absorbed efficiently through your digestive tract. In particular, alcohol impedes the absorption of B vitamins and zinc, both of which are important for healthy immune function.
Alcohol dehydrates you. The mucous membrane is your first line of defence against pathogens. You breathe in a virus, for example, and it gets stuck in the mucus. The virus gets flushed away and special immune cells identify it to prepare the body to fight the infection. If you are dehydrated, the mucous membrane does not function as effectively, leading to greater risk of infection.
Alcohol impairs sleep. It’s true that alcohol makes you sleepy and you may sleep longer after drinking but you won’t sleep as deeply. You have probably had the experience of falling dead asleep after drinking only to wake up feeling terrible a few hours later, then sleeping fitfully the rest of the night and into the next day. That’s not the kind of restorative sleep that helps your body fight infection and repair damage. The nights of bad sleep accumulate and make you more prone to illness.