November 21st, 2007 Milan
Every year, 1.2 million Americans have a heart attack.
Exercise affects the function of hearth muscle, but it also affects the blood vessels, from the large aortic artery to the large capillaries.
Exercise:
- can boost your HDL (“good”) cholesterol
- makes the lining of blood vessels more flexible
- has beneficial effects on risk factors for heart disease like lipids, blood pressure and insulin sensitivity
If partially blocked arteries are more elastic, they can relax better and send more blood to the heart muscles.
You don’t have to be an athlete to protect your heart.
In a study that tracked nearly 40 000 women for five years, those who walked briskly for at least an hour a week were half as likely to be diagnosed with hearth disease as those who did no regular walking. The risk was even lower for women who jogged or did other vigorous activity.
What’s more, researchers have tested the impact of exercise training on people who already have heart disease.
“If they are assigned to an exercise program, they have a lower risk of dying and dying from heart disease,” says I-Min Lee, associate professor of epidemiology at Harvard School of Public Health in Boston.
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November 5th, 2007 Milan
It’s bad enough that inactivity can turn your muscles to Jell-O. Can it do the same to your brain?
“The evidence is fairly solid that people who are more physically active are at lower risk for cognitive decline and dementia,” says Constantine Lyketsos, director of the division of geriatric psychiatry and neuropsychiatry at Johns Hopkins University School of Medicine in Baltimore.
For example, the brains of physically active mice have more nerves, more connections between nerves, fewer clogged arteries, more oxygen flow, and better ability to utilize glucose. All are probably factors in helping prevent cognitive decline and dementia.
Recent studies used mice that are prone to acquire the amyloid plaques that are found in the brains of Alzheimer’s patients.
At least one study suggest that if you take these mice out of their traditional cages, where there is little to do, and put them into stimulating cages with more colors, objects, brighter areas, and little mouse treadmills, you find fewer amyloid deposits in the brain.
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November 1st, 2007 Milan
“The evidence is fairly clear now that men and women who are physically active have a 30 to 40 percent lower risk of colon cancer compared to individuals who are not active,” says Harvard’s I-Min Lee, who examined dozens of studies.
Experts have several theories that might explain how physical activity protects the colon. ” It increases transit in the intestine, which makes food flow through fast,” says Lee. “So any carcinogens in the intestine have less contact with the cells that line the intestine.”
Another possibility is that regular exercise shores up the immune system. ” That would protect the body from any cancer, including colon,” she ads.
Than there’s the obvious: “Physical activity prevents weight gain, and the overweight have a higher risk of colon cancer,” says Lee.
How much movement is enough? “We don’t have precise data, but it looks like you need 30 to 60 minutes a day of moderate-intensity physical activity.” says Lee.
Regular exercise also appears to lower the risk of breast cancer by about 20 percent.
“We are not clear how much physical activity you need to reduce the risk of breast cancer,” says Lee. But it’s in the same ballpark as for colon cancer – between 30 and 60 minutes of moderate-intensity physical activity a day.”
As for some other cancers, she ads,”there’s some suggestive evidence, but it’s not as conclusive.”
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October 26th, 2007 Milan
“The one thing that seems to deteriorate quickest with inactivity is insulin sensitivity,” says Ben Hurley, a professor of kinesiology at the university of Maryland at College park.
Type 2 diabetes by far the most common kind occurs when the body becomes insensitive, or resistant, to insulin in the blood. When insulin stops working, blood sugar level rise and diabetes sets in.
Regular exercise reverses the damage.
“It increases insulin sensitivity and makes the cells better at taking in glucose and processing it,” explains I-Min Lee, an associate professor of epidemiology at the Harvard School of Public Health in Boston.
“The data are striking ,” says Hurley. And it’s not just and issue for adults. “Type 2 diabetes used to be a disease of middle age,” he adds. “But now we’re seeing it in young people. It’s a sedentary disease.”
Hurley sounds like researcher Steven Blair talking about the metabolic syndrome, which raises the risk of both diabetes and heart disease.
Doctors diagnose the syndrome when people have a large waist, low HDL (“good”) cholesterol, and elevated (though not necessarily high) blood pressure, blood sugar, and triglyceride.
“The metabolic syndrome is misnamed,” says Blair, who is president of the Cooper Institute in Dallas, Texas. “It ought to be called the inactivity syndrome.”
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