When you hear about a study that finds life-bestowing benefits from consuming something, you should have a foundation of information/thinking within which to fit it, you should consider who conducted the research, you should consider where it was published. And there is generally no more reliable, esteemed source for medical findings than the New England Journal of Medicine (NEJM).
Two new studies are now being publicized indicating, respectively, that nuts and caffeinated coffee make you live longer. These studies are consistent with previous research. The study of nuts and longevity was published in NEJM, and considered a quite large population (about 100,000 men and women). Although the television account I saw on MSNBC minimized this result because it was funded by the International Tree Nut Council, this critique is misguided. The research was co-funded by the National Institutes of Health and conducted by the Harvard Health Professionals research group. Someone has to pay for research, and the confidence of this Council that its product bestowed a long life is the most noteworthy aspect of their funding the research. The nut study results were impressive, indicating a 10-20 percent reduction in mortality in a straight-line linear function (increasing with the daily frequency of eating nuts). Although I already eat nuts (and certainly drink coffee and alcohol, see below), this research will actually cause me to change my behavior.
The caffeine study being publicized is interesting, but far less impressive. It was a small experimental study that found even small amounts of caffeinated coffee enhanced blood flow to the small blood vessels. This indicates a mechanism for reducing heart disease. What is most indicative about the current caffeine study is not the study, but the willingness of the American Heart Association to release a statement from the Japanese investigator supporting the heart benefits of caffeine: “This gives us a clue about how coffee may help improve cardiovascular health." But more important are prospective studies showing that caffeine drinkers prolong their lives. One large (400,000 men and women) prospective study conducted jointly by the National Institutes of Health and AARP and published in NEJM found a small but reliable (around 10%) reduction in mortality among older Americans (ages 50-71 at baseline). Coffee's life-bestowing benefit was actually slightly greater for those drinking 4-5 cups daily! However, the reduction in mortality was essentially the same from one (but not less) through six cups daily.
All of this pales, of course, compared with the massive body of research showing that alcohol has a large (twice that for coffee) beneficial impact on heart disease and overall mortality. There is an almost exactly parallel study to the caffeine study that appeared in the NEJM a decade-and-a-half ago with alcohol among the middle aged and elderly, sponsored by the American Cancer Society, including a half-million subjects. Drinking led to an overall 20 percent reduction in mortality. But if you want to see a finding that you are not allowed to know about in America, where fear-mongering for elderly drinking is a constant, consider this one from the NEJM study, the largest ever conducted of the elderly and drinking: "In the subgroup at highest risk for cardiovascular disease (60 to 79 years old with preexisting risk factors), the rates of death from all causes among drinkers remained significantly below those among nondrinkers, even for subjects reporting four or more drinks daily (L-shaped pattern)." It is a greater risk factor for the elderly not to drink at all than it is for them to drink too much.
This refusal to tell people about the best research on alcohol and mortality reminds us that an early finding in the legendary Framingham Heart Study that drinkers reduced heart disease was suppressed by the National Institutes of Health. In 2007 when PBS produced a show "The Hidden Epidemic: Heart Disease in America," the show's producer, its goofy moderator (Larry King), and all of the experts consulted never discussed moderate drinking. They couldn't say anything bad about it, like they did smoking, so they simply ignored the topic.
Go on and die, they were saying -- you'll never hear anything good about alcohol from our lips!
My new book (with Ilse Thompson) -- "Recover! Stop Thinking Like an Addict and Reclaim Your Life with The PERFECT Program" -- is available for pre-order.