MONDAY, Dec. 13 (HealthDay News) -- Sticking to a heart-healthy
lifestyle may also ward off Alzheimer's disease, according to a new
study that suggests that raising "good" cholesterol levels can help
prevent the brain disorder in older people.
The study, published in the December issue of
Archives of Neurology, found that people who had low levels of high-density lipoprotein (HDL) or "good" cholesterol had a 60 percent greater risk of developing Alzheimer's disease after the age of 65 than those who had high levels.
Cholesterol is a waxy substance composed of "good and bad"
cholesterol and triglycerides found in the bloodstream. More than
50 percent of the U.S. population has high levels of "bad"
cholesterol, according to the study.
"Our study suggests that high HDL levels ['good' cholesterol] are associated with a lower risk for Alzheimer's disease," said Dr. Christiane Reitz, the study's author. "Ways to increase HDL levels include losing weight [if overweight], aerobic exercise and a healthy diet."
By treating problems with cholesterol levels, "we can lower the
incidence of Alzheimer's disease in the population," said
Some medications, such as statins, fibrates and niacin, that are
used to lower "bad" cholesterol also raise "good" cholesterol, said
Reitz, an assistant professor of neurology at Columbia University's
Taub Institute for Research on Alzheimer's Disease in New York
More than 5 million Americans have Alzheimer's disease, the most
common form of dementia, and those numbers could triple by 2050,
according to health officials.
The U.S. National Institutes of Health reports that about 5
percent of Americans between the ages of 65 and 74 have late-onset
Alzheimer's disease, the more common form of the disorder, and the
prevalence increases with age. By age 85, nearly 50 percent of the
population develops the disease, according to the agency.
Early-onset Alzheimer's, a rare form of the disease, begins in
middle age and runs in families. Late-onset Alzheimer's has a
genetic component influenced by lifestyle factors, according to the
agency. There is no cure for Alzheimer's disease, but a few drugs
can help reduce symptoms for a time, according to experts.
However, people can cut their risk by reducing their intake of
trans-fats and increasing monounsaturated fats that keep "good"
cholesterol high and "bad" cholesterol low, said Reitz, noting that
drinking moderate amounts of alcohol also helps. Foods high in
monounsaturated fats include vegetable oils, avocados, peanut
butter and many nuts and seeds.
The 1,130 study participants were drawn from a random sample of
Medicare recipients in New York City. The participants were
screened for Alzheimer's, and those with symptoms were excluded.
Screening for the study began in 1999 and follow-ups were conducted
every 18 months until the data was analyzed in 2010.
Participants also underwent a battery of tests measuring mental
functions, such as memory, language processing, visual-spatial
orientation and executive function. Executive function allows
people to comprehend instructions and complete a given task.
During the study, 101 cases of Alzheimer's disease were
identified, at an average age of 83 years.
One weakness of the research is that it was conducted among
elderly residents of an urban community with a high prevalence of
risk factors, such as obesity, cardiovascular disease and diabetes,
according to the study. The findings may not apply to a younger,
One expert on the disease, Catherine M. Roe of Washington
University in St. Louis, said it was already known that "good"
cholesterol benefits the heart, but this study shows "an additional
reason to make sure we live a healthy lifestyle."
"These results are important because they suggest that an increase in HDL cholesterol may also help ward off Alzheimer's disease," said Roe, a research assistant professor at the school's Knight Alzheimer's Disease Research Center.
The study is strong because it used a large random sample of
elderly people, Roe added. But she cautioned that the results need
to be duplicated.
However, "since the authors did not find an effect of HDL
cholesterol in their previous, similar study, I think we have to be
cautious about these results until they are also demonstrated in
other samples," Roe noted.
In addition to eating a healthy diet, getting exercise and
losing weight as recommended by Reitz, Roe said that quitting
smoking could help people increase levels of "good"
"I think it's a great idea to talk with your doctor about what you specifically can do to live the healthiest lifestyle you can," Roe suggested.
To learn more about cholesterol levels, visit the
American Heart Association.