How Healthy Living Helps Longevity
Diet, Exercise May Boost Longevity by Keeping the Body Sensitive to Insulin
WebMD News Archive
July 19, 2007 -- Healthy living may extend longevity, and scientists have
new information about how that happens.
You probably already know that healthy habits like exercising and eating a
nutritious diet are good for you. Reams of research point to the head-to-toe
benefits of a healthy lifestyle.
A new study, published in the July 20th edition of the journal
Science, shows that a healthy lifestyle may extend longevity -- even
when the body isn't in tip-top shape.
"It has less to do with how we look, and more to do with a healthy
brain, especially in old age," says researcher Morris White, PhD, in a news
release from Children's Hospital Boston.
White works at Children's Hospital Boston and Harvard Medical School. He and
his colleagues studied longevity in mice, not people. But their study may have
implications for people.
"Our findings put a mechanism behind what your mother told you when you
were growing up -- eat a good diet and exercise," White says in a Howard
Hughes Medical Institute news release.
The researchers focused on the Irs2 gene, which makes a protein that helps
cells absorb insulin, a hormone that controls blood sugar.
The scientists completely or partially inactivated the Irs2 gene in the
brains of some mice. For comparison, they didn't tweak the Irs2 gene in other
The researchers monitored the mice's life span. With age, the mice gained
weight, spent less time scampering around their cages, and became less
sensitive to insulin.
Those changes happened for all of the mice, but the changes were
particularly pronounced in the genetically engineered mice.
Even so, the genetically engineered mice lived up to 18% longer and were
more active than the normal mice.
That may be because tweaking the Irs2 gene helped protect the brain from the
ravages of insensitivity to insulin, the researchers suggest.
Longevity in People
The study's take-home message isn't about tinkering with your genes.
Instead, the researchers suggest three simple health habits -- moderate
daily exercise, calorie restriction, and weight loss -- to help maintain
insulin sensitivity and perhaps help longevity.
Of course, people with impeccable health habits aren't exempt from illness,
and nothing guarantees a long life. White's study doesn't delve into all
the genetic and environmental factors that make for a long, healthy life.
But there's no reason not to go for your healthiest lifestyle. Need
pointers? Your doctor can help you set and reach goals for healthy living. Be
sure to check in with your doctor before starting a new exercise program.
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