Throughout life, the human body is constantly struggling: errors arise and are then corrected. As we get older, the balance appears to change, with an increasing risk that errors are not corrected. Now a Danish-German research collaboration has found evidence that the people who live longer have slower metabolism.
For humans to survive as a species simply requires that people survive long enough to have children. In pure evolutionary terms, life after 50 is really a waste. Why some humans live more than twice as long naturally interests both researchers and people in general. How do we live a long and healthy life?
A Danish-German research collaboration with researchers from Kiel University and University of Southern Denmark has therefore investigated 244 Danes and Germans to discover the characteristics of people who live to a ripe old age. Half the group was very old people, but was it their genes or how they lived that determined their long life?
To find the answer, the researchers examined which genes are expressed in very old people and compared the results with the genes expressed by people of average age – represented by the profile of the other half of the group. The difference here indicated that almost 20% can be attributed to inheritance, whereas 80% probably results from other factors that are important for regulating our genes.
Live slow die old
When the researchers examined the genetic data more closely, they discovered that the primary differences in gene expression between very old people and people of average age were especially linked to genes associated with metabolism and, to a lesser extent, to the regeneration of cells and tissue, and the immune system.
The researchers especially noticed the downregulation of the genes associated with metabolism and interpreted this as a sign that humans with slower metabolism may live longer. Although the results are far from conclusive, they support the results of previous studies on large and small animals showing that restricting calorie intake can extend life by up to 40%.
Nevertheless, the researchers emphasize that they cannot be certain that the very old people they studied had a similar metabolism and gene expression throughout their life. But the results underpin the wisdom of the old saying: live hard, die young. And that people can live to a very old age if they live life a little slower.
“Genetic interplay between human longevity and metabolic pathways – a large eQTL study” has been published in Aging Cell. The research project was headed by Almut Nebel and Robert Häsler from the Institute of Clinical Molecular Biology at Kiel University. In 2013, the Novo Nordisk Foundation awarded a grant to Kaare Christensen, co-author, Professor and Head of the Danish Aging Research Center, University of Southern Denmark for the project Progress in Health and Functioning among Exceptionally Long-lived Individuals? A study of Centenarians Born in 1895, 1905 and 1915.