Study links Alzheimer's with weight, Boston Globe,
By Alice Dembner
7/15/2003 -- Women who are significantly overweight at age 70 dramatically increase their risk of developing Alzheimer's disease, according to a study released yesterday that contributes to the growing evidence that what's bad for the heart is also bad for the brain.
On average, a woman who is 5 feet 4 inches tall and 145 pounds -- just on the cusp of being overweight -- increases her risk of Alzheimer's disease by 36 percent for every 7 pounds she gains, according to the study, published in the Archives of Internal Medicine. Overall, the risk increased by more than a third for every one point rise in a woman's body mass index, a standard measure of body size, beyond what is considered healthy.
''Maintaining a healthy weight looks like something you can do to help decrease the risk for Alzheimer's disease,'' said Deborah Gustafson, a researcher at Goteborg University in Sweden who directed the study.
The study did not find a similar effect for men at age 70, but researchers believe that may be because overweight men are less likely to live into their 80s. As a result, there were few in the study.
With the rate of obesity growing in the United States, the association between weight and Alzheimer's has broad public health implications. Nearly two-thirds of American adults are overweight or obese, according to the Centers for Disease Control and Prevention. Alzheimer's specialists said the study gives people one more reason to lose weight.
An estimated 4 million Americans have Alzheimer's disease, a number that is expected to soar as baby boomers approach the age when the risk of Alzheimer's grows. Currently, the only treatments approved by the Food and Drug Administration reduce the symptoms of Alzheimer's, but don't affect the progression of the disease. However, research has suggested that keeping mentally and physically active may help ward off the disease, which is characterized by progressive memory loss, disruptive behavior, and disorientation.
''The moral of the story is to lose weight, stop smoking, and exercise if you want to reduce your risk of dementia,'' said Dr. Janet Lawrence, former director of the Memory Clinic at McLean Hospital in Belmont, who was not involved in the new study. ''Anything that protects your blood vessels is good for protecting against Alzheimer's.''
Gustafson said the link between weight and Alzheimer's may reflect the body's biochemical response to fat or may be tied to vascular problems exacerbated by obesity such as atherosclerosis, high blood pressure, and coronary heart disease. Other research has suggested these conditions play a role in Alzheimer's.
''Body fatness may be contributing to dementia in addition to creating changes in the blood vessels that would alter blood flow to the brain,'' said Gustafson, an assistant professor at Utah State University.
Earlier studies had suggested a connection between body weight and Alzheimer's, but this is apparently the first to follow patients over a long period of time and to control for the potential effects of high blood pressure, smoking, and cardiovascular disease.
The study followed 392 Swedish adults from age 70 to 88 and found what researchers called a ''striking relationship'' between weight at age 70 and the development of Alzheimer's 10 to 18 years later.
Women who developed Alzheimer's had a body mass index that was typically 3.6 points higher than those who didn't. Body mass index, the standard measure for obesity, is calculated by taking the weight in pounds, dividing it by the height in inches squared, and multiplying that number by 703. (The CDC provides a BMI calculator at www.cdc.gov/nccdphp/dnpa/
bmi/bmi-adult.htm) A score of 25 or higher is considered overweight, and 30 or higher is considered obese But the research suggests that people don't have to strive to be skinny to reduce their risk. The women who did not get Alzheimer's had an average BMI of about 25.
''The data about obesity has been pretty spotty'' up until now, said William Thies, vice president for medical and scientific affairs at the national Alzheimer's Association, which helped fund the study. ''It's a well-done study, but we have to be a little cautious. I don't know whether [keeping your weight down] is definitely going to prevent Alzheimer's, but I do know you are going to remain as functional as you can for as long as you can.''
Although the study did not look at the impact of being overweight earlier in life, Gustafson said, most people who are overweight at 70 are heavy throughout their lives.
The association between weight and Alzheimer's has been difficult to study because people with the disease, even in its earliest stages, tend to lose weight.
Researchers believe this explains why they found no link between a person's weight at 70 and an increased risk of Alzheimer's in the next few years. It was only after 10 years of being overweight that they found the strong link.
The study found a weaker link between being overweight and dementias other than Alzheimer's, but did not find any connection to vascular dementia, which is marked by isolated effects on the brain rather than the overall deterioration of Alzheimer's.
Lawrence said she found that counterintuitive, since vascular dementias are caused by damage to the blood vessels in the brain. Perhaps, she said, those with vascular dementias died at an earlier age.
By Alice Dembner
7/15/2003 -- Women who are significantly overweight at age 70 dramatically increase their risk of developing Alzheimer's disease, according to a study released yesterday that contributes to the growing evidence that what's bad for the heart is also bad for the brain.
On average, a woman who is 5 feet 4 inches tall and 145 pounds -- just on the cusp of being overweight -- increases her risk of Alzheimer's disease by 36 percent for every 7 pounds she gains, according to the study, published in the Archives of Internal Medicine. Overall, the risk increased by more than a third for every one point rise in a woman's body mass index, a standard measure of body size, beyond what is considered healthy.
''Maintaining a healthy weight looks like something you can do to help decrease the risk for Alzheimer's disease,'' said Deborah Gustafson, a researcher at Goteborg University in Sweden who directed the study.
The study did not find a similar effect for men at age 70, but researchers believe that may be because overweight men are less likely to live into their 80s. As a result, there were few in the study.
With the rate of obesity growing in the United States, the association between weight and Alzheimer's has broad public health implications. Nearly two-thirds of American adults are overweight or obese, according to the Centers for Disease Control and Prevention. Alzheimer's specialists said the study gives people one more reason to lose weight.
An estimated 4 million Americans have Alzheimer's disease, a number that is expected to soar as baby boomers approach the age when the risk of Alzheimer's grows. Currently, the only treatments approved by the Food and Drug Administration reduce the symptoms of Alzheimer's, but don't affect the progression of the disease. However, research has suggested that keeping mentally and physically active may help ward off the disease, which is characterized by progressive memory loss, disruptive behavior, and disorientation.
''The moral of the story is to lose weight, stop smoking, and exercise if you want to reduce your risk of dementia,'' said Dr. Janet Lawrence, former director of the Memory Clinic at McLean Hospital in Belmont, who was not involved in the new study. ''Anything that protects your blood vessels is good for protecting against Alzheimer's.''
Gustafson said the link between weight and Alzheimer's may reflect the body's biochemical response to fat or may be tied to vascular problems exacerbated by obesity such as atherosclerosis, high blood pressure, and coronary heart disease. Other research has suggested these conditions play a role in Alzheimer's.
''Body fatness may be contributing to dementia in addition to creating changes in the blood vessels that would alter blood flow to the brain,'' said Gustafson, an assistant professor at Utah State University.
Earlier studies had suggested a connection between body weight and Alzheimer's, but this is apparently the first to follow patients over a long period of time and to control for the potential effects of high blood pressure, smoking, and cardiovascular disease.
The study followed 392 Swedish adults from age 70 to 88 and found what researchers called a ''striking relationship'' between weight at age 70 and the development of Alzheimer's 10 to 18 years later.
Women who developed Alzheimer's had a body mass index that was typically 3.6 points higher than those who didn't. Body mass index, the standard measure for obesity, is calculated by taking the weight in pounds, dividing it by the height in inches squared, and multiplying that number by 703. (The CDC provides a BMI calculator at www.cdc.gov/nccdphp/dnpa/
bmi/bmi-adult.htm) A score of 25 or higher is considered overweight, and 30 or higher is considered obese But the research suggests that people don't have to strive to be skinny to reduce their risk. The women who did not get Alzheimer's had an average BMI of about 25.
''The data about obesity has been pretty spotty'' up until now, said William Thies, vice president for medical and scientific affairs at the national Alzheimer's Association, which helped fund the study. ''It's a well-done study, but we have to be a little cautious. I don't know whether [keeping your weight down] is definitely going to prevent Alzheimer's, but I do know you are going to remain as functional as you can for as long as you can.''
Although the study did not look at the impact of being overweight earlier in life, Gustafson said, most people who are overweight at 70 are heavy throughout their lives.
The association between weight and Alzheimer's has been difficult to study because people with the disease, even in its earliest stages, tend to lose weight.
Researchers believe this explains why they found no link between a person's weight at 70 and an increased risk of Alzheimer's in the next few years. It was only after 10 years of being overweight that they found the strong link.
The study found a weaker link between being overweight and dementias other than Alzheimer's, but did not find any connection to vascular dementia, which is marked by isolated effects on the brain rather than the overall deterioration of Alzheimer's.
Lawrence said she found that counterintuitive, since vascular dementias are caused by damage to the blood vessels in the brain. Perhaps, she said, those with vascular dementias died at an earlier age.
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