Tuesday, July 19, 2011

It's a Fact: Exercise Reduces Stress

Did you know that scientists have located a part of the brain that controls our reaction to stress? Researchers at the National Institute of Mental Health (NIMH)  have found a specific circuit in the brain that reacts to stress and determined that physical exercise improves that specific part of the brain's ability to be resilient. Basically, the research confirms what a lot of us have believed for a while - that physical activity lowers stress levels. But more than that, consistent physical exercise wards off depression and mood disorders.

Scientists at the NIMH located this circuit in the brain by using lab tests on mice. Groups of mice who have lived a basically sedentary life are put in close quarters with mice who have had plenty of opportunity to exercise. (Mice, especially males, tend to get intensely aggressive when they are housed together in confined spaces.) In this environment, the mice who had lived a basically sedentary life exhibited greater signs of depression (especially after losing a confrontation with another mouse - what the researchers termed a "social defeat" - like losing a big argument at the office) and retreated into the more isolated and dark parts of the testing space. Meanwhile, the mice who had gotten plenty of exercise handled social defeats better, staying active, and stayed close to the rest of the mice in lighted areas.

A central target of this research is understanding how stress contributes to mood disorders and why some animals and people seem resilient to the same stresses that can make others ill. The NIMH and others are trying to determine if there are ways to fix abnormalities in how the brain deals with fear memories or other stressors.

It's an interesting concept that makes sense. If you exercise, on a consistent basis, not only will your body be more resilient to fighting disease, but your mind will be more resilient as well.

What do you think of this research? Does it make sense? How does your activity level affect your mood and ability to handle the stress in your life? Post a comment here, on Facebook or on Twitter.

Friday, July 1, 2011

Sunscreen: New Labeling Will Help You Know Which is Right for You

After a few weeks of early summer heat, I thought it would be a good time to talk about sunscreen, especially after the Food and Drug Administration's recent rule changes that should really help you make better sun protection choices starting next summer. The FDA's new guidelines are designed to "reduce consumer confusion," said Dr. Janet Woodcock, the director of the FDA's Center for Drug Evaluation and Research. 
Starting in 2012, sunscreen products may be labeled "broad spectrum" if they block UVB radiation and a percentage of UVA radiation. UVB is the major cause of sunburn, but both can cause premature skin aging and skin cancer. Broad spectrum sunscreens with an SPF over 15 can now claim to reduce the risk of skin cancer and premature aging - because the FDA has determined that they do. Also, you will no longer see sunscreens with an SPF listed above 50. Instead, the bottle will be labeled 50+. According to Dr. Woodcock, "We don't have sufficient data to show that those [sunscreens] with an SPF higher than 50 provide greater protection." 
Products will also no longer be able to called "sunblock," because there is no evidence that they can actually block all of the radiation in sunlight. One last claim that will be eliminated starting in 2012 is that sunscreens are "waterproof" or "sweatproof." Sunscreens can only now be called "water resistant" and must clearly state how long that protection lasts - generally 40 or 80 minutes.

Unfortunately, you probably won't see any of these label changes this summer (although some at the FDA are hopeful that sunscreen companies will adopt the rule changes before next summer), but this definitive information from the FDA should be a good guideline for you during the high sun exposure months this summer.

Sunscreen is integral to protecting your skin from burns, skin damage, premature skin aging, and skin cancer. Any sunscreen with an SPF less than 15 is basically just lotion. Remember to try to stay out of the sun during peak times, usually 10am-2pm, if possible and use a "broad spectrum" lotion liberally and reapply regulary.
Do you have a family member who is lax about sun protection? How do you try to keep your family safe from excessive sun exposure? Leave a comment or drop a question about how your family can stay safe this summer.