Staying active later in life helps your lifespan and your health span
Forget the image of grandparents slowing down and retiring to their rocking chairs. A new study from researchers at Harvard explored the “active grandparent hypothesis” to show why and how exercise later in life prolongs health span and helps fight chronic diseases.
Cape Cod family medicine physician Arash Tadbiri, MD says just thinking about the difference between health span (years spent in good health) and life span (getting older, but not necessarily remaining healthy as we age) could be enough to motivate many people, not just grandparents, to stay physically active.
“Exercise is so important I wish I could write a prescription and have patients follow that,” said Dr. Tadbiri, who also has advanced training in and a strong interest in geriatric medicine. “Exercise isn’t just a recommendation, it’s a medicine. Even in wintertime, don’t quit. Find the type of exercise that you enjoy so that you’ll want to exercise.”
“The news that we should exercise is not new,” Dr. Tadbiri added, “but it is exciting to understand why and how humans are made for exercise in the middle and later years of life. This study does away with the concern you shouldn’t exercise when you are older because you might get hurt.”
The study lays out evolutionary and biomedical evidence showing that humans, who evolved to live many decades after they stopped reproducing, also evolved to be relatively active in their later years, according to a Harvard press release introducing the study. The research team believes their paper is the first detailed evolutionary explanation for why lack of physical activity as humans age increases disease risk and reduces longevity. They conclude: “Physical activity is physiologically stressful, causing damage to the body at the molecular, cellular, and tissue levels, but the body’s response to this damage, however, is essentially to build back stronger.”
The notion of the body’s ability to “build back stronger” is one of the most important takeaways of this study, according to Dr. Tadbiri. This research explains how physical activity later in life shifts energy away from processes like storing fats and sugars, which add to inflammation and are bad for us, he said.
According to The Harvard Gazette, the active grandparent hypothesis says that humans evolved to remain physically active as they age and in doing so to allocate energy to physiological processes that slow the body’s gradual deterioration over the years. This guards against chronic illnesses such as cardiovascular disease, Type 2 diabetes, and even some cancers.
“We know exercise reduces inflammation, which causes pain and diseases. Exercise increases the number of white blood cells in the blood stream. White blood cells are soldiers—the first responders and first detectors to fight any agent such as cancer and other diseases,” said Dr. Tadbiri.
He said people often think that if they are active when they are older, they might injure themselves. But, this study found that some stress (injury) to the body is helpful.
“Interestingly, this study shows small injuries—such as microfractures of the ligaments as you run—are healthy. Microfractures shift the body’s energy to repairing the tiny fractures, and this repair and maintenance process produces some anti-inflammatory agents and antioxidant agents that keep older people healthier. In the absence of physical activity, the body’s energy goes toward storing fat and hormones that increase the opportunity for cancer and other diseases,” he said.
Exercise is important, he concluded. “Any type of activity that you enjoy and that keeps you moving is helpful. We don’t want everyone to walk a marathon. I usually tell patients to walk at least a half hour a day. If walking isn’t for you, I encourage you to find some other exercises, because exercise is healthy for so many reasons.”
