Decades ago, the New England Journal of Medicine published an article that implicated coffee as a cause of pancreatic cancer. The study was terribly flawed and was soon debunked. For a while, researchers looked into coffee as a cause of heart disease. In a reversal of fortunes for the coffee industry (and for millions who need a launching pad to start the day), recent studies have shown that coffee, in moderation, helps to prevent heart disease. Eggs have been on a roller coaster ride too. Currently, eggs are in the nutritionists’ “good for you” category. Seven eggs per week is OK.
In the 1980s, the “French Paradox” surfaced. Investigators noted a low prevalence of heart disease among the French, despite eating a diet rich in fatty foods. The French also enjoy quantities of red wine in excess of almost all other countries, and studies began to appear that it was not only protective from heart disease, but was also a factor in warding off dementia. Some studies said that the positive effect, if there is a positive effect, was from alcohol itself, not necessarily the wine.
Research over the years on this matter of alcohol ingestion has been all over the place. Recently, alcohol’s reputation has hit a bad patch. Some experts are now claiming that the best level of imbibing is no imbibing.
Good News for the Liquor Industry
Now along comes a study from South Korea that must find the Budweiser execs toasting that peninsula. Investigators there looked at the drinking habits of four million people over the course of two years, and followed them up on average about seven years later with tests to detect dementia. They categorized all of the subjects into five groups (“cohorts” in the medical lexicon): sustained non-drinkers; quitters; those who reduced alcohol ingestion but did not stop; those who maintained the same of level of drinking throughout the two years; and those who increased the intake of alcohol, including those who started the study as non-drinkers. Questionnaires that subjects filled out determined the category they fell into.
Compared to teetotalers, mild and moderate drinkers had a 21% and 17% reduced risk for dementia, respectively. Heavy drinkers (those who drank three or more alcoholic beverages per day) had an eight percent increase in the risk for dementia. Most remarkably, non-drinkers who became mild drinkers during the two year period had an eight percent reduction in risk for dementia, compared to sustained mild drinkers.
The Study Is Far from Definitive
The study has its weaknesses. As with all cohort studies, one group might have undetected characteristics independent of what is being studied that affects the outcomes. Also, self reporting in nutritional and dietary studies is notoriously unreliable. It must be noted that this study did not look at cardiovascular risk, and that no one is recommending the institution of drinking as a preventive intervention for general health.
Nevertheless, the liquor industry will probably jump on this study and begin to highlight the supposed beneficial effects of mild drinking. Executives in the alcohol industry should probably send a present to the South Korean investigators at Christmas… maybe a case or two of scotch.
Thanks for another thoughtful and well-informed essay, Jim. Either way we interpret the data, it appears we can continue our 4-to-6-drinks-a-week habit unimpaired by guilt.
Time for our dinner glass of wine, or two!
Another problem with the generalizability of the results is that the Korean peninsula is relatively isolated from a genetic point of view and thus the results may be skewed. These are the kind of results which are “hypothesis-generating” rather than a study on the epidemiology of dementia.
Slainte Mhath..Gaelic for Good Health