Is It Smart to Drink?

A surprising chart was posted by Razib Khan. In the General Social Survey, the higher Americans score on a vocabulary test, the more likely they are to drink alcohol:


Of course we know that correlation is not causality, so one should not immediately infer that reading drives one to drink, or that drinking improves memory (perhaps because, as the old joke argues, alcohol kills weaker brain cells, increasing the average quality of the brain).

It does, however, raise a serious question:  Is it smart to drink?

Epidemiology Recommends Moderate Drinking

Most people have read of the studies that show that moderate drinkers – who drink, say, a glass of wine or two with dinner – tend to have the best health, while teetotalers and alcoholics have the worst.

A recent prospective cohort study confirms this pattern and shows it to be surprisingly strong.

The study followed 1,824 adults, initially between ages 55 and 65, for 20 years.  Their conclusion: “even after adjusting for all covariates, abstainers and heavy drinkers continued to show increased mortality risks of 51 and 45%, respectively, compared to moderate drinkers.” [1]

This is a pretty large effect. Without their adjustments, heavy drinkers had a 70% higher mortality rate, abstainers 23% higher. Still large, although not so bad for abstainers. If the choice is alcoholism or abstention, go with abstention.

What About the Biology?

Epidemiological studies often mislead due to confounding factors.  It would be nice to learn from biology that alcohol is safe.

A primary safety concern with alcohol is its effect on the liver. Alcohol consumption can produce fatty liver disease and, eventually, a scarred and damaged liver (cirrhosis).

Interestingly, in animal studies the harmful effects of alcohol on the liver occur only when it is combined with polyunsaturated fats:

  • Researchers induced liver disease by feeding mice a combination of alcohol and omega-3-rich fish oil.  They then stopped the alcohol and split the mice into two groups, one fed fish oil plus glucose, the other palm oil plus glucose. (Palm oil consists predominantly of saturated fat, and is less than 10% polyunsaturated.) Livers of the fish oil group failed to recover, but the palm oil group “showed near normalization.” The researchers hailed saturated fat as “a novel treatment for liver disease.” [2]
  • Mice fed 27.5% of calories as alcohol developed severe liver disease and metabolic syndrome when given a corn oil diet, but no disease at all when given a cocoa butter diet. (Corn oil is 55% polyunsaturated, cocoa butter is predominantly saturated fat and is less than 3% polyunsaturated.) The first line of this paper begins, “The protective effect of dietary saturated fatty acids against the development of alcoholic liver disease has long been known.” [3]
  • Scientists induced liver disease in mice by feeding alcohol plus corn oil.  They then substituted a saturated-fat rich mix based on beef tallow and coconut oil for 20%, 45%, and 67% of the corn oil. The more saturated fat, the healthier the liver. [4]

This makes biological sense. Alcohol is metabolized in the liver just like fructose, a toxic sugar. Polyunsaturated fats are chemically fragile and quick to react with sugars; saturated fat, which lacks fragile carbon double bonds, does not.

It seems that if you keep your liver clear of polyunsaturated fats, the alcohol will be disposed of safely.

What Does This Mean on the Perfect Health Diet?

Our diet is very low in polyunsaturated fats:  We eat as few omega-6 fats as possible, and purposely include only 1 lb of oily marine fish per week in order to get long omega-3 fats.

Thus, two dinners per week may have omega-3 fats, other meals will be largely polyunsaturated fat free.

Mice on a saturated fat (cocoa butter) diet can get 27.5% of calories as alcohol with no liver damage. In humans, that would correspond to a daily 350 ml (12 fluid ounce) bottle of 80-proof gin, rum, or vodka, or a liter (36 fluid ounces, 1.3 bottles) of red wine.

We don’t recommend such alcohol intakes! That said, it does seem to confirm that there is little risk in moderate alcohol consumption, if the rest of the diet is sound.

For Perfect Health Dieters, perhaps on salmon days alcohol should be limited to a single glass of wine. In general, however, moderate drinking should hold no concern.

Oh, and for you alcoholics, a little friendly advice: If you value your liver, remove polyunsaturated fats from your diet. The safest foods? Red meats and seafood; starches (rice, sweet potatoes, potatoes); vegetables; butter/cream and coconut oil.

References

[1] Holahan CJ et al. Late-Life Alcohol Consumption and 20-Year Mortality. Alcohol Clin Exp Res. 2010 Aug 24. [Epub ahead of print] http://pmid.us/20735372. Full text: http://onlinelibrary.wiley.com/doi/10.1111/j.1530-0277.2010.01286.x/pdf. (Hat tip:  Robin Hanson, http://www.overcomingbias.com/2010/09/alcohol-is-healthy.html)

[2] Nanji AA et al. Dietary saturated fatty acids: a novel treatment for alcoholic liver disease. Gastroenterology. 1995 Aug;109(2):547-54. http://pmid.us/7615205.

[3] You M et al. Role of adiponectin in the protective action of dietary saturated fat against alcoholic fatty liver in mice. Hepatology. 2005 Sep;42(3):568-77. http://pmid.us/16108051.

[4] Ronis MJ et al. Dietary saturated fat reduces alcoholic hepatotoxicity in rats by altering fatty acid metabolism and membrane composition. J Nutr. 2004 Apr;134(4):904-12. http://pmid.us/15051845.

Leave a comment ?

66 Comments.

  1. Further to my query above, apart from salmon and Omega-3-rich fish with wine, how about nuts (which are rich in Omega-6) such as roasted, salted pistacchios which are often served with pre-prandial drinks (aperitivi) in most Italian bars and cafés?
    Would you suggest passing over the nuts and focusing on the cheese and salami (which are also similarly served)?
    This wine-cum-Omega3 issue has got some of my Italian friends really intrigued.
    Thanks in advance for your advice (again, without any rush!)
    Cheers
    Kevin

  2. Pedro Guimarães

    Hi, i found it really interesting but it’s also safe to drink beer? They have gluten. There is a type of beer that’s is safer than others? I know that the beers whith clear color has less gluten, but i read that the darker ones have more fermentation. Can you help me with these questions? Here in Brazil we love beers.

    Thanks

    Pedro.

  3. Drink Smart and in Moderation « Terre Pruitt's Blog - pingback on February 20, 2014 at 2:45 pm
  4. Hi Paul,

    I tend to get my DHA/EPA in throughout the week at work by adding tinned fatty fish with my first meal at lunch. Adding 3oz or so Monday through Friday.

    I’d like to no I’m not shooting myself in the foot by coming home to some cheese and crackers with a small glass of wine while I prep dinner, and then possibly a second small glass of wine with dinner consisting of low PUFA seafood or ruminants (don’t usually enjoy wine with pork or chicken).

    Would it be more healthful to get my pound of omega-3s in via 2 or 3 meals throughout the week and avoid alcohol on those nights? Or do you think such a low dose earlier in the day (6-7 hours before dinner) is unlikely to affect my liver?

  5. Hi Paul,

    I drink 1-2 glasses of red wine each night and I’m currently taking a break (along with giving up sugar) and switching more toward your diet (though I was almost there, naturally, as a gluten free person, who doesn’t use vegetable oils). I’m taking a break from wine hoping it helps a sinus infection/ allergies. (I hope I’m not allergic to wine!).

    I came across this interesting article, which describes a study that shows benefits to the liver when moderate drinkers abstein for one month. Your thoughts?

    http://www.newscientist.com/article/mg22129502.600-our-liver-vacation-is-a-dry-january-really-worth-it.html?page=1#.VLFk2P2d_8F

Leave a Comment


NOTE - You can use these HTML tags and attributes:
<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>