Much of human health hinges on how well the body manufactures and uses energy. For reasons that remain unclear, cells’ ability to produce energy declines with age.
This prompts scientists to suspect that the steady loss of efficiency in the body’s energy supply chain is a key driver of the aging process.
Now, scientists at Washington University have shown that supplementing healthy mice with a natural compound called NMN can compensate for this loss of energy production.
NMN can reduce typical signs of aging such as gradual weight gain, loss of insulin sensitivity and declines in physical activity.
The study is published Oct. 27 in the journal Cell Metabolism.
NMN can be given safely to mice and is found naturally in a number of foods, including broccoli, cabbage, cucumber, edamame and avocado.
The new study shows that when NMN is dissolved in drinking water and given to mice, it appears in the bloodstream in less than three minutes.
Importantly, the researchers also found that NMN in the blood is quickly converted to NAD in multiple tissues.
To determine the long-term effects of giving NMN, the researchers studied three groups of healthy male mice fed regular mouse chow diets.
Starting at 5 months of age, one group received a high dose of NMN-supplemented drinking water, another group received a low dose of the NMN drinking water, and a third group served as a control, receiving no NMN.
The researchers compared multiple aspects of physiology between the groups, first at 5 months of age and then every three months, until the mice reached 17 months of age. Typical laboratory mice live about 2 years.
The researchers found a variety of beneficial effects of NMN supplementation, including in skeletal muscle, liver function, bone density, eye function, insulin sensitivity, immune function, body weight and physical activity levels.
But these benefits were seen exclusively in older mice.
NMN supplementation has no effect in the young mice because they are still making plenty of their own NMN.
Since human cells rely on this same energy production process, the researchers are hopeful this will translate into a method to help people remain healthier as they age.
The researchers are now conducting a clinical study to test the safety of NMN in healthy people.
Citation: Mills KF, et al. (2016). Long-term administration of nicotinamide mononucleotide mitigates age-associated physiological decline in mice. Cell Metabolism, published online, DOI: http://dx.doi.org/10.1016/j.cmet.2016.09.013.
Figure legend: This Knowridge.com image is credited to Michael Worful.