August 09, 2015

Food for Thought

The global anti-aging industry is valued at over $195 billion and will grow to $275 billion by 2020. But the assessment of the effectiveness of its products made by three leading scientists in 2002 has not changed. And what they said is that “no currently marketed intervention—none—has yet been proved to slow, stop, or reverse human aging, and some can be downright dangerous.” They then go on to say that "the public is bombarded by hype and lies." Or, as one of the triumvirate put it in a recent NY Times article, "as soon as the scientists publish any glimmer of hope, the hucksters jump in and start selling."  
In light of this reality, my internal alarms started going off when I saw the headline in last week’s NY Times, “My Dinner with Longevity Expert Dan Buettner (No Kale Required).Granted, the article was in the “Fashion and Style” section of the Times, not the health section and not the science section. Now don't get me wrong: diet and exercise do matter: eating well and remaining active decrease the chance of developing disease and disability. Not only that, but modifying what you eat in the hope that it will promote longevity is far more benign than purchasing expensive supplements or herbal remedies that have no proven efficacy and are quite possibly harmful. But still—is Dan Buettner really a “guru of the golden years” who has spent “the last 10 year unlocking the mysteries of longevity?” He traveled to five of the places on the globe with the longest lived people: Icaria, Sardinia, Okinawa, the Nicoya Seaside of Costa Rica, and Loma Linda, California and wrote up his interviews. He was not funded by the NIH as the report would have us believe: he was funded by National Geographic to report on peoples who were being studied by teams of scientists funded by NIH. He did write a cover story for National Geographic in 2005 about the people he met on his travels and how they lived, particularly how they ate. And he converted his article into a book, The Blue Zone Solution, published by National Geographic Press this past spring.
            National Geographic ran a cover story about diet and longevity once before. The magazine reported in 1973 on Dr. Alexander Leaf’s travels to the Caucasus where he studied people who ostensibly were 120 years old. It would turn out that these human marvels were actually only in their nineties, at best. In fact, according to Dr. Tom Perls, head of the New England Centenarian Study, 98% of claims of age over 115 are false, as are 65% of claims to be 110. 
            I’m not sure why the NY Times ran this story. But I was sufficiently intrigued to look into what we do know about diet and longevity.

         For starters, it’s important to distinguish between people who live a long time and people who live a very long time. What is pretty clear is that the variability in life span for people in the first category can be explained by a mixture of environmental and genetic factors. We can’t control who our parents were, but we can control, to some extent, our environment. So what we eat is one of the things that does matter, at least as far as increasing our chances of making it into our eighties is concerned. Exceptional longevity—centenarians and “super-centenarians” (people over age 110) are a different story. For this group, it’s all about genetics. 
            But can we say much more than what was concluded from the Whitehall study, a longitudinal study of aging in Canada that found the 4 behaviors that increased the chances of being in good health after age 60 are regular physical activity, eating fruits and vegetables daily, drinking alcohol in moderation, and not smoking? What do we learn by looking at  the dietary habits of people in Buettner’s “blue zones” of above average longevity?  
          For several decades, geriatrician Bradley Willcox and his twin brother, anthropologist Craig Willcox, have been leaders of the Okinawan Centenarian Study. They have identified a variety of factors which, together, seem to account for the long lives of Okinawans. It’s not just about diet. It’s also about living in a culture that values group activities and fosters a strong sense of community. It’s about living in a slower paced, low pressure world where people get around by bicycle. But yes, it’s also about diet. And while each of the longevity hot spots of the world has its own culinary specialties, they all have much in common. They all feature a high intake of unrefined carbohydrates and a moderate intake of protein, mainly from fish and legumes. Their foods have a low glycemic load, include a goodly number of anti-oxidants, and are low in saturated fats.
         How much of a role diet plays in the 30-50% of longevity that is due to environmental factors is unclear. Also unclear is whether diet interacts with social factors to make a difference. It’s conceivable that what you eat matters, but it matters a good deal more if you also live in an all-embracing community. At least as interesting as the Sardinians and the Costa Ricans are the Seventh Day Adventists of Loma Linda (whom, to be fair, Buettner visited as well). The people of Loma Linda are physically active and tend to be vegetarians. They are also very involved in their community and deeply committed to their religious faith. So maybe, just maybe, it’s not only what we eat that determines how long we live. Just some food for thought.

No comments: