People like to get healthy, burn body fat, increase their aerobic capacity, and improve their cognitive function. The ketogenic diet is an excellent way to obtain those outcomes, which partially explains its meteoric rise in popularity. But people also like to drink alcohol. You might say it’s a toxin—I wouldn’t disagree. You might say we’d be better off without it—perhaps. The fact remains that people have been drinking for tens of thousands of years, and they’re not going to stop anytime soon.
Can keto and alcohol coexist? Is there anything we need to take into consideration?
A 2002 study out of Poland examined the bodies of 16 recently deceased people who had died from hypothermia, mostly alcohol-induced. Most were alcoholics. They found that ketone levels and blood-alcohol levels were inversely proportional. The higher the blood alcohol, the lower the ketones. The higher the ketones, the lower the blood alcohol. In the discussion section, the authors explain:
Liver cells ‘‘engaged’’ in ethanol utilization do not accumulate larger amounts of Ac-CoA (which is a substrate for ketogenesis) because an increase in the NADH/NAD ratio during ethanol oxidation inhibits b-oxidation of fatty acids, and the acetate created from ethanol is activated to AcCoA mainly in the non-liver tissues which cannot produce ketone bodies.
In other words, at a high enough intake, alcohol metabolism supersedes and inhibits ketogenesis because both processes occur in the liver along similar pathways. The Polish study is an extreme example—alcoholics, hypothermia, death—but the basic mechanism is sound.
In real world situations, however, where people are having a drink or two, low-sugar alcohol (red wine, spirits) is unlikely to derail ketosis. Sugary drinks will inhibit ketosis because of the sugar. Alcohol-induced junk food bingeing will inhibit ketosis because of the junk you’re eating. But it appears to take some serious doses of ethanol to make a noticeable dent in your ketone production. Even then, a degree or two less ketosis isn’t the end of the world (unless you have a serious health condition warranting constant ketosis, in which case are you sure you should be drinking?).
A friend of mine, Mark Moschel, is the health evangelist for Dry Farm Wines and an avid keto dieter and self-experimenter. He recently ran an interesting experiment to determine the effects of his low-sugar dry-farmed wines on ketosis. (If you’re a numbers junkie and love charts, you’ll appreciate seeing how he put it together.)
He fasted for three days to get deep into ketosis. Two days in, he opened a bottle of wine and started drinking.
After the first glass, there was no change. Ketones and blood sugar held steady.
After the second glass, ketones dropped a bit. Sugar rose a bit.
After the third, ketones dropped some more. Sugar went down this time.
Yet, at no point was he “out of ketosis.” Even after the third glass, he was still showing 1.4 mmol. And upon waking the next morning, he had bounced back to 2.3 mmol. By the afternoon, ketones were back above 4 mmol.
Something tells me the “3-day wine fast” is going to catch on in some circles….
Maybe. A commonly reported side effect that hasn’t been shown in studies (because the studies haven’t been done) is reduced alcohol tolerance on keto. People report getting drunk quicker and having worse hangovers. Let’s assume for the sake of this post that it’s true, that the anecdotes are conveying something that’s actually happening to a large portion of the keto-eating world. What could be causing reduced alcohol tolerance?
Alcohol detoxification occurs along two enzymatic pathways, one of which—the CYP2E1 pathway—is also activated by ketone bodies. The CYP2E1 pathway is ultimately a detox pathway, but some of the metabolites it produces in response to the various toxins it processes, like alcohol, acetaminophen (Tylenol), and tobacco, can increase liver inflammation and peroxidative damage. If the ketones you’re making are triggering CYP2E1, drinking alcohol may put you over the top and push you toward greater oxidative stress.
This could explain part of the reason why drinking on an empty stomach (fasting, hence elevated ketones) tends to heighten the toxicity and enhance the hangover.
A high-fat diet can very quickly become a high-omega-6 fat diet if you aren’t careful about the foods you’re eating. You’re eating out for lunch every day at Chipotle; it’s low carb, but everything is cooked in rice bran oil. You’re snacking on almonds and sunflower seeds. Your favorite meat is whole chicken with the skin on, and you use the chicken drippings to cook up a bunch of greens. The more fat, the better, right?
All those foods are moderately-to-very high in omega-6. If that’s a daily diet, you’re getting upwards of 30+ grams of omega-6 fats, mostly linoleic acid. Why is this a problem specifically in the context of alcohol?
Omega-6 fatty acids, especially linoleic acid, are particularly harmful when you drink alcohol:
Polyunsaturated fats combined with alcohol also raise CYp2E1 more than alcohol alone, an indication of the combination’s toxicity.
High-fat diets are liver-intensive. The more fat you eat, the more choline you need to help metabolize it. High-fat diets with inadequate choline can lead to fatty liver, even if you’re eating the most Primal-friendly balanced source of fats.
Alcohol is also liver-intensive. The more alcohol you drink, the more choline you need to help metabolize it. High-alcohol diets with inadequate choline almost always lead to fatty liver, even if you’re drinking the healthiest, purest sources of ethanol.
Combining alcohol and a high-fat ketogenic diet requires even more choline than either alone. The best sources of choline are egg yolks and liver. Make sure you’re eating enough of one or the other to support your liver.
Whether it’s coffee, chocolate, ginger, turmeric, green tea, the phytonutrients within the wine itself, or even non-psychoactive cannabidiol in cannabis, most plants make alcohol less toxic. Keto dieters who drink should definitely eat some or all of these foods.
Alcohol consumption presents a few notable challenges to people following a ketogenic diet, but they aren’t by any means insurmountable. Provided you eat a good ketogenic diet—not too much omega-6, adequate choline, plenty of phytonutrients— and make good beverage choices, moderate amounts of alcohol shouldn’t throw you out of ketosis or pose any special threat to your health.
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