Beer is said to be the nectar of the gods, and as such, you’d think it would be life-giving. But can you actually live on just beer? Dr. Aaron White, senior scientific advisor at the National Institute of Alcohol Abuse and Alcoholism, says only a hopeless drunk would think that’s a good idea―and he has the science to prove it.
First up, water: If you kept to a strict beer diet, swearing off plain water altogether, you’d die of dehydration within a matter of days, possibly weeks. While beer itself contains plenty of water―the average beer is around 92 percent water by weight, according to White―the alcohol’s diuretic effect (that is, its ability to increase your production of urine) makes it a net negative in terms of hydration under most conditions. In simpler terms, beer makes you pee out more water than you’d retain from drinking it, so there’s no way of keeping yourself hydrated enough to stay alive.
If you were to include plain water as a part of your beer-only diet, you’d still fall victim to scurvy (a nasty disease resulting from a lack of vitamin C that can cause gum disease, bleeding from the skin and even a slow death from infection) within three months. “Alcohol in and of itself is energy dense, but that doesn’t necessarily make beer nutritious,” White explains. The problem, as with the hydration question above, is with how much of it ends up leaving your body as pee. A single serving of beer can contain up to 30 milligrams of vitamin C—meaning that if you chose the right beer, you could technically consume the recommended daily vitamin C intake for adults (65 to 90 milligrams)—but since alcohol causes the body to expel vitamin C faster than usual, it’s not going to do you any good.
This isn’t just theory, either: British researchers tested the effects of a beer-based diet during the 1920s by feeding two Rhesus macaque monkeys 200 millilitres of India pale ale each day, along with some other foods lacking in vitamin C. Within just 37 days, “well-defined symptoms” of scurvy appeared in one monkey—the other monkey fell victim to the very same symptoms just 20 days later.
If you were somehow able to skirt the effects of scurvy, beer is notably deficient in vitamins A, D, E and K, as well as thiamine (a vitamin that helps the body convert fuel into food), protein and fat. “The average beer contains 150 calories, approximately 1.6 grams of protein, 12.6 grams of carbohydrates and small amounts of various vitamins and minerals,” White adds. This means that a diet of just beer could induce the thiamine deficiency-driven disease known as beriberi, which if left untreated, can trigger heart failure.
Protein deficiency is also a major (and more immediately alarming) risk, with the potential to cause muscle wasting and anaemia. This loss of muscle mass would eventually lead to the characteristic “skin and bones” appearance that comes with starvation, which is more or less what your body is reduced to when it’s deprived of protein. To get the recommended daily intake of protein from beer (56 grams per day for the average sedentary man), you’d have to drink 3.5 gallons a day: That’s around 35 12-ounce beers every single day, which would almost certainly leave you passed out on someone’s front lawn with alcohol poisoning. But hey, at least you wouldn’t starve to death—you can die of scurvy, instead!
Next time you get to thinking all you need is beer, just remember these wise words from Dr. White: “Beer might be delicious, but it wouldn’t sustain life on its own forever.”