A physician and his team of researchers at the National Institutes of Health (NIH) have discovered an enzyme they believe might one day be blocked by a pill. They have identified an enzyme called DNA-dependent protein kinase (DNA-PK) which becomes more active in mid-life, i.e., the 40s and 50s when most of us tend to get so-called "middle-aged spread."
DNA-PK acts to convert the nutrients we eat into fat rather than being used for immediate energy or a ready source of glucose, the basic "sugar" molecule our muscles and bodies use for the activities of daily living. And the enzyme also unfortunately reduces the numbers of mitochondria in our cells, the energy-producing parts that turn food into energy. Without adequate or higher numbers of these little powerhouses, everything in our bodies begins to flag--energy, maintaining weight, activity levels, sexual drive, cognitive ability, interests and a positive mental attitude. Because this is such a normal part of the aging process for most individuals, the old adage, "Aging is not for the faint of heart," is more true than most would like to admit.
However, a drug these researchers gave mice in their study gained 40 percent less weight than mice not given the drug as they advanced into "middle age." Whether or not this would apply to humans remains to be seen but it is the great question left unanswered and one well worth pursuing.
We have often attributed the weight gain and lack of regular exercise in middle age to poor lifestyle choices and lack of willpower. But this study indicates that there really is a genetic basis to the weight gain and loss of exercise capacity during midlife that just worsens with age. Being able to modify an overactive enzyme that reduces critical pathways of metabolism and energy production could provide an incredible opportunity for older Americans to regain some of their youthful stamina and energy, not to mention prevent further obesity in the United States.
This study shows that DNA-PK is one of the drivers of the metabolic and fitness decline that occurs steadily throughout middle and old age which makes staying leaner and more physically fit that much more difficult as we age. And at the same time, it increases susceptibility to metabolic diseases like diabetes and insulin resistance, both in epidemic proportions today.
Clearly, the challenge ahead of us is to learn how to modify these processes whether through a "pill" or other health-promoting forms of changing the way our bodies work. Until then, the best we can do is to eat sensibly, exercise in ways that help preclude injuries and keep our stress under better control with techniques like meditation or yoga.
Hopefully, there will be a "pill" one day that can make a real difference in our quality of life, without the side-effects that so many other drugs have. It seems like a future worth hoping for.