Friday, January 10, 2014

Need a New Year’s Resolution? Try Exercise!

By Ahmed Raza Khan, MD, MPH
Child and Adolescent Psychiatry Physician at Stanford University School of Medicine

Most people know that exercise is beneficial for cardiac health and is prescribed by physicians for the prevention and alleviation of various medical complications. But what if I told you exercise can also significantly benefit your mental health in more ways than one? Let’s take a look at some of the ways exercise can improve mental health and how to incorporate this into your new year’s resolution list!
Exercise and Depression Prevention:More than 350 million people in the world suffer from depression and it is the leading cause of disability worldwide.  Exercise has often been considered as a supplemental tool in treating depression, but recent evidence points to exercise playing a role in the prevention of future depressive episodes. These recent findings show that even low levels of physical activity (e.g., walking less than 150 minutes a week) can prevent future depression. There has been significant research in the last few years that links cardiovascular health’s role in the origin of depression. This would certainly be a plausible explanation for why exercise may prevent depression.

Alzheimer’s Disease Prevention:Alzheimer’s disease is a chronic, degenerative disease of the brain that affects over 25 million people in the world. This illness leads to a progressive mental decline, steering its victims to dependence on caregivers and, eventually, death. Amyloid plaques are abnormal clusters of protein fragments that are found in the brains of patients with Alzheimer’s disease and are thought to play a major role in its progression. Recent studies have found that people who exercised at or above the levels recommended by the American Heart Association had significantly lower numbers of amyloid plaques than those who exercised less. This was the case for even those who carried the APOE-e4 gene variant, which is an established risk factor for Alzheimer’s disease. When people with the APOE-e4 gene variant were compared, those with higher levels of exercise had lower levels of amyloid plaques.

Improving Cognitive Functioning:Exercise has been shown to increase cognitive functioning in rats. As rats get older, their memory tends to diminish and this appears to be due to a drop of nerve synapses in the hippocampus, the memory center of the brain. But after 12 weeks of voluntary running, both memory and hippocampus nerve synapses were restored in these rats.

Consistency in Exercise:Recent neuroscientific studies have shown that the cognitive benefit of exercise may have a window of time. In fact, rats that improved their cognitive functioning by exercise, had this improvement dissipate in 3-6 weeks of inactivity. This is similar to what is seen with muscle mass or heart rate when exercise is withdrawn. This evidence intimates that exercise is beneficial for the brain and should be performed consistently.

The American Heart Association is a great resource for planning the amount and type of exercise one needs. They recommend at least 30 minutes of moderate-intensity aerobic activity at least 5 days a week for a total of 150 minutes or at least 25 minutes of vigorous aerobic activity 3 days a week for a total of 75 minutes. An easy target to remember: 30 minutes a day, 5 days a week.