Apr 04,2008 00:00
If statistics from the U.S. Centers for Disease Control and Prevention are to be believed, then there's an even chance that you, like half of all Americans, are overweight.
New research published March 26 in the online edition of the journal Neurology shows that the extra weight we carry around our bellies when we are in our 40s can lead to an increased risk of dementia when we reach our 70s.
Scientists in Northern California studying the link between weight and disease measured the bellies and kept track of more than 6,500 people for an average of 36 years. All the participants first entered the study when they were between the ages of 40 and 45.
Over the life of the study, 16 percent of the participants were eventually diagnosed with dementia. The study found that those with the most abdominal fat were nearly three times as likely to develop dementia than those with the least abdominal fat.
"Considering that 50 percent of adults in this country have an unhealthy amount of abdominal fat, this is a disturbing finding," said study author Rachel A. Whitmer of the Kaiser Permanente Division of Research in Oakland, Calif., and member of the American Academy of Neurology.
Having a big belly increased the risk of dementia regardless of whether participants were of normal weight, overweight or obese, and regardless of existing health conditions, including diabetes, stroke and cardiovascular disease.
Among the study findings:
- Overweight participants with large bellies were 2.3 times more likely to develop dementia than those with a normal weight and belly size.
- Obese people with large bellies were 3.6 times more likely to develop dementia than those of normal weight and belly size.
- Those who were overweight or obese but did not have a large abdomen had an 80 percent increased risk of dementia.
While recent research has shown that a large belly in midlife increases the risk of diabetes, stroke and coronary heart disease, the Kaiser study was the first to illustrate the connection between excess body weight and dementia.
"Autopsies have shown that changes in the brain associated with Alzheimer's disease may start in young to middle adulthood, and another study showed that high abdominal fat in elderly adults was tied to greater brain atrophy," Whitmer said. "These findings imply that the dangerous effects of abdominal obesity on the brain may start long before the signs of dementia appear."
Neurology is the medical journal of the American Academy of Neurology and can be found online at www.neurology.org.
A recent study of the breakfast-eating habits of more than 2,200 students reports that the more often adolescents eat breakfast, the less likely they are to be overweight, says a study published in the March issue of Pediatrics.
For five years, the researchers examined the eating and exercise habits of about 1,000 boys and 1,200 girls, with an average age of 15 at the start of the study. The participants came from a racially and economically diverse sample of Minnesota public school students.
The study authors noted previous research that shows breakfast consumption of adolescents declines as they grow into young adulthood. Other studies associate that decline with weight gain.
Study co-author Mark A. Pereira, associate professor of epidemiology at the University of Minnesota, said his team wanted to examine the link between breakfast frequency and 5-year body weight change.
The study found a direct link. The more often a participant had breakfast, the lower his or her body mass index. And whether researchers looked at the data at a given point or analyzed changes over time, that relationship persisted.
Pereira provided one theory to explain the relationship. He said eating a healthy breakfast could help to "promote healthy eating throughout the day and might help to prevent situations where you're grabbing fast food or vending machine food."
He said evidence indicates breakfast-eaters consume greater amounts of carbohydrates and fiber, get fewer calories from fat and exercise more. Other researchers suspect the consumption of fiber-rich breakfast foods might improve glucose and insulin levels, making people feel more satisfied and less likely to overeat later in the day.
In the Pediatrics study, participants recorded their food intake using a common food frequency questionnaire.
Participants were also asked specific questions about how often they ate breakfast as well as what outside forces might affect their eating. They were asked if they had concerns about their weight, if they ever skipped meals to lose weight, if they had ever been teased about their weight, and how often they had dieted during the previous year. They were also asked about exercise.
About half the study participants ate breakfast consistently. The study found that girls were more likely to skip breakfast and that boys were more likely to eat breakfast every day.
At the start of the study, consistent breakfast eaters had an average body mass index of 21.7, intermittent eaters 22.5, and those who never had breakfast 23.4. Over the next five years, BMI increased in exactly the same pattern. The relationship persisted even after taking into account age, sex, race, socioeconomic status, smoking and concerns about diet and weight.
E-mail Ven Griva or write to P.O. Box 120190, San Diego, CA 92112.© Copley News Service