Don't Lose Your Mind - Exercise

With the New Year come resolutions and one of the most popular choices is exercise. Americans have heard about the benefits from the news to the doctor's office - it's good for your heart, it increases the good cholesterol, and so on. But you may not know what it can do for your brain during all stages of your life. Exercise and Depression Millions of retirees might find their brains in better shape if they keep their bodies in better shape. And pregnant moms might find their babies' brains developed a wee bit better if they would increase their physical activity. And the plusses don't stop there. "We also know other benefits of physical activity can reduce your body fat percentages and improve your ability to metabolize glucose in your bloodstream, possibly if you were a diabetic. But other than that, there hasn't been a lot of research looking into how physical activity might change your brain function or your mental health," Dr. Jacquie Van Hoomissen said. Van Hoomissen says all of the attention on exercise and heart disease caused the brain to be overlooked. That's part of why she went into this field -- and because there's depression going back in her family several generations. "I started to wonder if those people in our family who did not suffer from depression -- what could be one of the reasons. I noticed with myself that I didn't actually suffer from depression, but I was also very physically active and have been my entire life," Van Hoomissen said. Types of depression affect more than 20 million American adults a year - that's almost 10 percent of those aged 18 and older. Now there is growing evidence that exercise could put a dent in depression. Even a small dent would save millions in money and misery. Van Hoomissen said, "If their depression is severe enough you still will need those medications, but the exercise could be an additive treatment to help you manage those symptoms and bring that back under control." Keeping Your Mind Sharp Other positive aspects of this research deal with keeping our minds sharp as we age. Again exercise appears to be a significant factor. One way this benefit may kick in is that exercise helps produce more of a special substance called brain-derived neurotrophic factor, or BDNF. BDNF acts on the nerve cells of the brain. That action helps nerve cells survive longer. And BDNF also helps new nerve cells form from flexible units we know as stem cells. "This was somewhat of a surprise to the field of neuroscience -- so for many years people thought the brain was created in utero and we never could get more brain cells after you were born -- you just had the number you were born with," Van Hoomissen said. The net effect is a brain that can withstand more wear and tear, and a brain that's more protected. Excess stress reduces the release of BDNF in lab animals. That leads to damage by shrinking a key part of the brain, the hippocampus. In humans, the hippocampus is important to memory, and damage there causes many of the problems from Alzheimer's disease. Again exercise could help counter all of that by upping the amount of BDNF produced. At the other end of life, scientists are studying what happens to babies of active pregnant moms: "Now we do have a little bit of evidence to show that even physical activity during pregnancy could potentially be beneficial for our children as they're growing," Van Hoomissen said. And there are the moms themselves. Van Hoomissen has applied for grants to study those women who have to be on bed rest during pregnancy -- and thus miss out on exercise: "We're interested to find out: 'Are these women who have had this stressful experience recovering the same?' And maybe we should have a program in place after they give birth to help them get back on that exercise track," she said. So whether it's depression, stress, memory, or pregnant moms and their babies -- scientists want to know how much and what kind of exercise will be best. "The recommendations for physical activity will be different for each of those different types of clinical situations," Van Hoomissen said. "And we'll have to figure out what works best for each of those patient populations." Research on the benefits of exercise for the brain is progressing. And enough is known to suggest that people should be doing a little brisk walking to keep their minds charged up.