Could dietary decisions be the key to longer living?
Since the beginning of written history humans have made a connection between diet and longevity, although it was always more a matter of educated guesswork than strong science. One of the most widespread early health foods was garlic, which was used by ancient Greeks, Egyptians, and Chinese to treat a variety of ailments as well as to promote overall health and spirit (1). From these early remedies, to 15th century global explorations for the fountain of youth, humans have always been pursuing an end to aging.
Today, even with a vast scientific knowledge advantage over our ancient counterparts, we still are not much closer to determining what diet best promotes long life and high quality of life. Due to the complexity of the human body as well as the huge amount of uncontrollable external factors, running any sort of true clinical tests is beyond unfeasible. The best (and most easily obtainable) data is to study the diet and lifestyles of existing centenarians (people at least 100 years old) and try to find common patterns.
Author and National Geographic fellow Dan Buettner has put in a significant amount of research on how maximizing lifespan. In his 2012 book “Blue Zones”, he identified five areas on earth, the namesake “Blue Zones”, where life expectancy is about 8 years higher than global average and people are three times more likely to reach 100 years old (3). These areas are: Sardinia, Italy; Lomo Linda, California; Nicoa, Nicaragua; Ikaria, Greece; and Okinawa, Japan. While obviously there is significant variance in diet due to local crops and culinary traditions, there are some commonalities between them.
All blue zone diets are relatively light in meat, and get the bulk of their protein from beans and nuts, whether that be black beans in Greece, soybeans in Japan, or pinto beans in Nicaragua. They also eat a high number of vegetables and fruit, always local and fresh as most of these zones are themselves farming communities. In the Italian, Greek, and Japanese communities alcohol consumption also plays an important role. Wine and sake contain a high amount of antioxidants, and the alcohol portion of both drinks reduces cortisol production in the brain, a hormone associated with stress (2). Researchers also found that people in these areas have a high day to day level of physical exercise, usually because walking is the primary mode of transportation.
As important as the physical health benefits provided by the diet of Blue Zone citizens are, the real separation from mainstream American society seems to be the mental health benefits from the community and lifestyle in these Blue Zone societies. People in these societies are very social and involved in their communities - familial and religious. Moreover, they often live with or near younger generations of their family. They report very low levels of depression or loneliness,and have a very strong sense of purpose, whether it be from commitment to their religion or family. These factors heavily contribute to the mental fortitude of the elderly in these communities, contrasted to the 50% rate of Alzheimer's in Americans 85 and older (2).
In summary, mental sharpness and ability to maintain independence is what people really are looking for when they want to increase longevity (certainly not time spent bedridden) but rather “good years”. It follows that if Americans want to increase the quality and length of their lives, we need to look scrutinously at both our diet and our lifestyle.
1) Rivlin, R. Historical Perspective on the Use of Garlic, The Journal of Nutrition, Volume 131, Issue 3, 1 April 2001, Pages 951S–954S, https://doi.org/10.1093/jn/131.3.951S
2) Worrall, S. “Here Are the Secrets to a Long and Healthy Life.” National Geographic, 12 Apr. 2015, news.nationalgeographic.com/2015/04/150412-longevity-health-blue-zones-obesity-diet-ngbooktalk/.
3) Buettner, D. (2012). The Blue Zones: 9 lessons for living longer from the people who've lived the longest.