About 9,000 years ago, people in Northern China concocted the world’s first alcoholic beverage: a grape and hawthorn fruit-based wine.[*] Humans have been drinking ever since.
Today we’ll review the health consequences of that practice, including how alcohol affects weight loss, sleep, gut health, brain health, and other aspects of wellness. We’ll also tackle FAQs like “Does alcohol slow metabolism?”
As a health-savvy reader like you knows, heavy alcohol consumption has devastating health effects.[*] And while moderate alcohol intake (up to 1 daily drink for women and 2 for men) may have isolated health benefits, it’s hard to know if those benefits outweigh the costs.
But you can decide for yourself after reviewing the facts.
How Alcohol Affects Weight Loss
The question, “Does alcohol cause weight gain?” seems like an easy one. Alcohol contains seven empty calories per gram, so why wouldn’t it derail weight loss efforts?
And yes, some data suggest that alcohol abstention is better for weight management than light, moderate, or heavy drinking.[*] But it also shows that folks can drink and lose weight simultaneously if they’re dialing in other lifestyle interventions.
Also, limiting alcohol isn’t an automatic ticket to losing weight. In one study on 283 overweight and obese adults, decreasing alcohol intake didn’t lead to weight loss over a 26-session behavior change program.[*]
Yet there’s a wrinkle to this data. The most impulsive folks (who also reduced alcohol intake) did lose weight.
“Alcohol consumption,” state the authors, “may lead to overeating episodes, and highly impulsive individuals may be at risk for increased energy intake during or after episodes of drinking.” In other words, drinking puts impulsivity (the munchies) on overdrive.
Health Effects of Alcohol
We’ll move quickly through these effects. Click the references to go deeper.
Countless people use alcohol as a sleep aid.[*] (It decreases the time to fall asleep.) But beyond that quasi-benefit, it’s bad news.
Drinking alcohol disrupts sleep architecture, suppressing valuable REM and deep sleep in the second half of the night. It’s linked to breathing problems, like snoring and sleep apnea. It decreases sleep duration. It leads to daytime sleepiness.[*]
Alcohol makes good sleep hard to come by. If you’re going to drink, keep it light and stop as early as possible so you can metabolize it before hitting the sack.
On Gut and Liver Health
Digesting alcohol does damage. For instance, drinking causes dysbiosis of the gut microbiome and perpetuates “leaky gut,” leading to nutrient deficiencies and chronic inflammation.[*]
From the gut, alcohol travels (via the portal vein) to the liver to be metabolized into a potent toxin called acetaldehyde. The liver can handle small amounts of acetaldehyde, but higher levels promote liver cell death, fatty liver, and cirrhosis.[*]
On the Immune System
When the gut takes a hit, immunity suffers too. (About 70% of our immune cells reside in the gut.) Suppressed immune systems mean chronic drinkers are at higher risk of infections.[*]
On Heart Health
Heavy drinking is uncontroversially bad for the heart, but moderate drinking may not be. Some researchers believe that small amounts of alcohol may reduce heart disease risk by decreasing clotting and increasing HDL cholesterol.[*]
But we don’t know for sure. Moderate drinkers have lower cardiovascular mortality than abstainers, but this could be explained by socioeconomic factors (access to better care) or by the fact that many abstainers used to be alcoholics.[*] Also, a 2023 study found that even one drink per day significantly raises blood pressure, a well-documented heart disease risk factor.[*]
On Brain Health
We drink alcohol for its effects on the brain. The pleasant buzz, the carefree vibe, the courage to approach an attractive stranger without frantically Googling pickup lines first.
But other effects are not so pleasant.[*] Drinking alcohol can:
- Reduce grey and white matter volume (even light drinking)
- Increase the risk of falls, fights, or accidents
- Damage brain cells directly
- Lead to neurotoxic withdrawal symptoms later
The general theme is that you get a short-term benefit in exchange for long-term detriment.
Alcohol and Health FAQ
You probably have lingering questions about alcohol and your health. Let’s see if we can answer them below.
Are there any benefits of alcohol?
Sure. Benefits of moderate drinking include:
- The pleasure of intoxication
- Social lubrication
- Temporary stress reduction
- The joy of wearing a shirt that says “You Had Me at Merlot”
- Possible cardiometabolic improvements
- Finding “great complexity, cacao overtones, and traces of shoe leather” in your cabernet as strangers look on in bewilderment
Are some kinds of alcohol healthier than others?
Red wine is probably the “healthiest” libation due to its high concentration of polyphenols. But despite rumors to the contrary, alcohol (ethanol) itself doesn’t vary (chemically speaking) from beverage to beverage.
What’s the best alcohol for weight loss?
Look to dry wines, spirits, and light beers with no added sugar to minimize empty calories. But if you want to optimize for weight loss, abstention is best.
What about research correlating moderate drinking with longevity?
That data typically doesn’t control for abstainers (often former alcoholics) and socioeconomic class.[*] When scientists control for these factors, the link between moderate drinking and longer life disappears.[*]
How does alcohol affect metabolism?
There’s no evidence that alcohol “slows” metabolism, though consuming ethanol can hinder fat burning—similar to carbohydrate consumption.[*] Other data suggest that light to moderate drinking may improve blood sugar and insulin metrics.[*]
Does alcohol metabolize into sugar?
No. Here’s what happens when alcohol reaches the liver:
- Alcohol dehydrogenase turns alcohol into acetaldehyde
- Aldehyde dehydrogenase turns acetaldehyde into acetate
- Acetate is converted to water and carbon
So the end products are water and carbon (not sugar), but damage can accrue along the way.
Does alcohol impair muscle building?
Probably. A review of 12 studies found that consuming alcohol decreases testosterone and muscle protein synthesis in the post-exercise recovery period.[*] Drinking also increases cortisol, a hormone that promotes muscle breakdown.
Will alcohol sabotage a healthy lifestyle?
It depends on the dose. Many people can tolerate 1–2 drinks daily without significant negative health impacts.
But that doesn’t mean moderate drinking is good for everyone. Abstention seems to be the healthiest route for many organ systems, sleep, and weight loss.
Your plan with alcohol should be tailored to you. Are you the kind of person who can occasionally have 1–2 drinks and cut yourself off? Great—you probably don’t need to make changes.
But if you notice yourself going beyond that dose and frequency, you might want to reassess your drinking habits. Avoid alcohol for 2–4 weeks and see how your sleep, energy levels, and body weight respond.
The results might surprise you. And don’t worry—if you want to re-enter the world of libation, a glass of aged boysenberry, vanilla beans, and fresh pencil shavings will be waiting for you.