The shorter a person was, the longer they lived, according to research that was recently published in the journal PloS One. The newly analyzed data reveals a link between short height and long life in Japanese men, which researchers believe all depends on a special longevity gene.
"We split people into two groups — those that were 5-foot-2 and shorter, and [5-foot-4] and taller," said Dr. Bradley Willcox, one of the investigators for the study and a Professor at the University of Hawai`i's John A. Burns School of Medicine's Department of Geriatric Medicine, in a press release.
The collaborative efforts by researchers at the Kuakini Medical Center, the UH John A. Burns School of Medicine, and the U.S. Veterans affair, found a protective form of the gene, FOXO3, stunted growth early-on in development and created a smaller body size. The longevity gene provided a longer lifespan, and those who were shorter were also less likely to have high blood insulin levels or develop cancer.
The FOXO3 gene was discovered in 2010 by German researchers at the Christian Albrechts University, who found that many of those who had the gene lived past their 100th birthday. Everyone has the gene, however it is the variant of that gene that matters when it comes to age, which can be tested for through whole-genome sequencing. Researchers concluded that the gene either plays a decisive role in the maintenance of stem cells or the immune system.
"The folks that were [5-foot-2] and shorter lived the longest. The range was seen all the way across from being 5-foot tall to 6-foot tall. The taller you got, the shorter you lived,” said Dr. Willcox.
Researchers looked at a longitudinal study from the Kuakini Honolulu Heart Program (HHP) and the Kuakini Honolulu-Asia Aging Study (HAA) of 8,006 American men of Japanese descent who were born between the years 1900 and 1919. The men were closely followed for 50 years, which makes it the only research program that has such a large and detailed collection of each man’s demographics, lifestyles, medical information and biological specimens.
"This study shows for the first time, that body size is linked to this gene," said Dr. Willcox. "We knew that in animal models of aging. We did not know that in humans. We have the same or a slightly different version in mice, roundworms, flies, even yeast has a version of this gene, and it's important in longevity across all these species."
Of those 8,006 men, approximately 1,200 of them lived into their 90s and 100s, and of those, nearly 250 are still alive today. However, Dr. Willcox notes in the study that height does not necessarily guarantee a shorter lifestyle and much of it hinges on the individual’s health and lifestyle.
"One of the reasons why Honolulu is perfect for this kind of study is that we have the longest-lived state in the country, combined with a population that has remained, for the most part, in Hawaii. This has helped us maintain one of the longest-running, largest studies of aging men in the world, in the Kuakini Honolulu Heart Program," Dr. Willcox said.
Source: He Q, Morris B, Willcox B, et al. Shorter Men Live Longer: Association of Height with Longevity and FOXO3 Genotype in American Men of Japanese Ancestry. PLoS One. 2014.