Middle-Age Cholesterol Not Alzheimer's Risk for Women

New research has found that women with high cholesterol levels at middle age are not at a greater risk of developing Alzheimer’s disease and other forms of dementia later in life, contradicting the long-held belief that such was the case.

“Our research refutes the notion that high cholesterol in midlife is a risk factor for Alzheimer’s disease, at least among women,” Michelle M. Mielke, Ph.D., an assistant professor of psychiatry at the Johns Hopkins University School of Medicine and the study’s lead author, says in a statement from the school.

The findings, which counter other scientific evidence linking the two, did find that women whose cholesterol levels dropped between middle age and old age were at a 2.5 times greater risk of developing dementia and other memory-wasting diseases than women whose cholesterol levels increased or remained the same. The study was published online in the journal Neurology.

Despite the findings, Mielke says people still need to keep their cholesterol levels in check because high levels can cause cardiovascular and other diseases.

For their study, Mielke and colleagues from Johns Hopkins, SUNY-Downstate Medical Center in Brooklyn, N.Y., and the University of Gothenburg in Sweden looked at data on 1,462 Swedish women ages 38 to 60 from the Prospective Population Study of Women that began in 1968. The women were questioned about smoking and drinking habits, medication use, medical history, and education.

They also underwent blood and heart tests, and physical examinations, and had chest X-rays. Body mass index (BMI), a measurement of body fat based on height and weight, and blood pressure were taken throughout the study.

Follow-up testing was done four times, with the most recent exams ending in 2001. During the 32 years of the study, from 1968 to 2001, neuropsychiatric tests also were performed. In 2001, 161 women in the original group had been diagnosed with forms of dementia, including Alzheimer’s disease. The youngest group was reaching age 70; the greatest known risk factor for dementia is old age.

Researchers say that women with slightly higher BMI, blood pressure, and cholesterol levels are healthier overall than those whose weight, blood pressure, and cholesterol levels are considered too low. What is not known, they say, is whether such too-low conditions are actual risk factors for dementia or signs that it is developing; before dementia develops unintended weight loss often occurs.