March 17, 2023
Exercise in a Pill
By Ram Rao, Ph.D., Principal Research Scientist for Apollo Health
A daily physical exercise regimen is the secret to remaining physically and mentally strong and active. Exercise strengthens and protects the body and the brain. In general, aerobics, weight-bearing endurance exercise, resistance exercise, exercises for stability, and exercises that improve balance are all needed in some form as they strengthen the bones, muscles, joints, and vertebrae. Exercise boosts total energy expenditure, decreases total body fat, optimizes blood sugar and insulin levels, improves heart health, stimulates systemic and cerebral blood flow, improves sleep, dampens inflammation, reduces mood swings, and stimulates neuronal branching. Furthermore, it stimulates the bone cells and restructures the bone fibers, resulting in increased bone mass and improved bone stability — a benefit for young and old alike.
Prolonged sitting and sedentary activities from lack of exercise are linked to numerous problems, including obesity, high blood pressure, osteoporosis, cardiovascular disease, and cancer, among others. Our ancestors naturally spent many hours outdoors walking, hunting, and foraging for food. Physical exercise to them was just a part of daily living. Compare this to our modern world, where physical activity is considered an intervention — something we do to prevent the negative consequences that result from a sedentary lifestyle. Scientists warn that even if you perform daily exercise but engage in prolonged sitting for eight to ten hours, it will offset any benefits that come from the exercise.
Now, for those that just do not love to exercise, there is favorable news in the form of an “exercise pill.” In a study to understand the mechanism by which exercise confers its benefits, researchers drew blood from young and elderly mice that were on an exercise regimen for six weeks. They then transfused the blood to two groups of elderly, sedentary mice. A third group of elderly, sedentary mice that received blood from ‘non-exercising’ mice served as controls. The researchers noted that the elderly, sedentary recipient mice that received blood from the ‘exercised mice’ performed better on cognitive tests irrespective of whether their transfusions came from young or old runners compared to the elderly controls. New neuronal branching appeared in mouse brain memory centers. The results suggested that irrespective of the animals’ age, the donors’ exercise regimen was more important as it impacted the memory centers.
Using various biochemical techniques, the researchers later identified a protein that gets elevated after exercise. The researchers then injected the ‘exercise factor’ in old, inactive mice. They showed that these old animals performed almost like young mice on learning and memory tests, and their brains were richly endowed with new neuronal cells. In short, the old mice gained the benefits of exercise in the brain without exercising. To check if the results of the study would hold true in humans, the scientists drew blood from elderly people that had a daily exercise practice and examined the levels of this protein. Indeed, the people who exercised showed higher levels of the same protein in their blood compared to those who did not exercise.
The combined upshot of these findings seems to be that exercise stimulates the release of a protein, which somehow improves brain health. If this protein were encapsulated in a pill, then this ‘exercise pill’ would be attractive for someone that cannot or does not enjoy exercise. I want to add a word of caution that while the results do hold a promise of an exercise pill that could be given to people who are too frail or disabled to engage in any physical activity, there are several shortcomings to the study. The researchers did not test the effects of the protein on other tissues or organs. The researchers failed to identify other exercise-inducing factors that were also present in the blood, so it may be that sustained benefits may require more than one factor in the exercise pill. It is also not clear if the same complex processes that occur in the brain with physical exercises would occur similarly with an exercise pill.
While we wait for more study results about this pill, I would suggest engaging in a variety of age-appropriate light physical activities. Aerobic, strength training, and mind-body exercises have been found to be beneficial for optimal brain health. While it would be ideal to combine all three, choose whatever exercise suits you best and engage in it daily. Research suggests that any kind of physical activity offers neuroprotection as long as you are healthy enough to engage in it without harm. For example, you could begin your day with stretching, followed by an endurance activity, or include some strength exercise. Or, you might choose to alternate activities throughout the week. When adopting a fitness mindset, you will not need an exercise pill as you will discover novel ways to incorporate physical activity throughout your day.