Along comes more evidence that suggests you will live longer and more productively if you get up off your sofa and exercise moderately.
A large study, presented Feb. 20 at the American Stroke Association's International Stroke Conference 2008 in New Orleans, followed 60,000 men and women for an average of 18 years. It found a significant connection between a moderate level of cardiorespiratory fitness and a reduction of the risk of stroke, the No. 3 cause of death in the United States.
"Fitness has a protective effect regardless of the presence or absence of other stroke risk factors, including family history of cardiovascular disease, diabetes, high blood pressure, elevated cholesterol levels and high body mass index," said Steven Hooker, the study's lead author and director of the Prevention Research Center at the University of South Carolina Arnold School of Public Health.
"This study is the first to suggest that there may be a significant independent association between cardiorespiratory fitness and fatal and nonfatal stroke in men and nonfatal stroke in women," said Hooker.
The American Stroke Association estimates that 780,000 U.S. adults suffer a stroke each year. Stroke is often fatal, claiming about 150,000 lives annually, according to the Centers for Disease Control and Prevention in Atlanta. What's more, stroke is a leading cause of serious, long-term disability in the United States.
Scientists examined data collected from 46,405 men and 15,282 women who participated in the Aerobics Center Longitudinal Study between 1970 and 2001 at the Cooper Aerobics Center in Dallas. During that time, 692 men and 171 women in the study suffered strokes.
What makes this study different is that participants were administered treadmill tests to measure their cardiorespiratory fitness. Many previous studies had depended on participants to self-report their fitness levels, Hooker said.
This is also the first study to explore the association between cardiorespiratory fitness and stroke risk in women.
Men who tested in the top 25 percent of cardiovascular fitness had a 40 percent lower risk of stroke when compared to men in the bottom 25 percent, the study found. Women who measured in the top 25 percent of fitness level had a 43 percent lower risk than those in the bottom 25 percent.
What made the findings particularly heartening for people who dislike exercise is that lowering their risk of stroke does not require strenuous workouts.
"We found that a low-to-moderate amount of aerobic fitness for men and women across the whole adult age spectrum would be enough to substantially reduce stroke risk," Hooker said.
The study was supported by grants from the National Institutes of Health and the Communities Foundation of Texas.
A study in Great Britain has found a new front in the fight against childhood obesity: salt.
Children who eat less salt drink fewer sugary soft drinks. Consequently, they might significantly lower their risks for obesity and elevated blood pressure, researchers reported in Hypertension: Journal of the American Heart Association. It might also lead, later in life, to a decreased risk of heart attack and stroke.
Previous studies in adults have shown that the increased salt consumption has a corresponding increase in fluid consumption. Researchers at St. George's University of London were the first to examine this connection in children.
"Sugar-sweetened soft drinks are a significant source of calorie intake in children," said Dr. Feng J. He, the study's lead author. "It has been shown that sugar-sweetened soft drink consumption is related to obesity in young people."
He, who is a woman, and colleagues analyzed data from the 1997 National Diet and Nutrition Survey in Great Britain. The survey examined more than 2,000 children and adolescents between 4 and 18 years old.
The salt and fluid intake of more than 1,600 boys and girls was recorded using a seven-day dietary log. The food and drink consumed by study participants was weighed on digital scales.
"We found that children eating a lower-salt diet drank less fluid," said He, a cardiovascular research fellow at St. George's. "From our research, we estimated that 1 gram of salt cut from their daily diet would reduce fluid intake by 100 grams per day."
From their research, they predicted that reducing salt intake by 1 gram per day would reduce sugar-sweetened soft drink consumption by 27 grams per day, after considering other factors such as age, gender, body weight and level of physical activity.
"If children aged 4 to 18 years cut their salt intake by half - i.e., an average reduction of 3 grams a day - there would be a decrease of approximately two sugar-sweetened soft drinks per week per child ...", He said. "Not only would reducing salt intake lower blood pressure in children, but it could also play a role in helping to reduce obesity."
He recommends that parents examine the labels of the foods they purchase for their children and choose low-salt food products. He also suggests refraining from adding salt during cooking and at the table. She also urges parents to challenge the food industry to reduce the amount of salt routinely added to children's foods.
E-mail Ven Griva or write to P.O. Box 120190, San Diego, CA 92112.
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