Alzheimer's disease: some fats might protect, others may harm

February 18, 2003 in Nutrition Topics in the News

Alzheimer's disease: some fats might protect, others may harm
Some studies suggest diet has no influence on the risk of Alzheimer\'s disease, while others show the opposite. New research released this week suggests that people 65 or older who eat relatively high levels of unhealthy fats in their diets appear to be more likely than others to develop Alzheimer\'s disease.

The good news is that the more vegetable fat people ate, the lower their risk of Alzheimer\'s. A diet high in unhydrogenated, unsaturated fats (such as mono- and poly-unsaturated fats) also appeared to protect people from Alzheimer�s disease. The current study adds to the evidence that not all fat is bad for you.

However, suggestions of the benefits of vegetable and unsaturated fats on the risk of Alzheimer\'s and dementia remain relatively new and inconclusive, so it is too early to recommend that people follow a certain diet to keep their memories intact.

In the current study, researchers from the Rush-Presbyterian/St. Luke\'s Medical Center in Chicago conducted dietary surveys of 815 people at least 65 years old who were dementia-free. They then tested them for Alzheimer\'s an average of two years later. During the study period, 131 participants developed Alzheimer\'s. People who consumed the most saturated fats had a more than two-fold higher risk of developing Alzheimer\'s than people who ate the least amount of saturated fats. High consumers of so-called trans fats were also more than twice as likely to be diagnosed with Alzheimer\'s as people who ate the least trans fat.

This is not the first study to examine the link between dietary fat and dementia. However, previous findings have been mixed, and the relationship between diet and dementia remains less than clear. Animal studies have shown that a high-cholesterol diet increases the build-up of Alzheimer\'s-related brain proteins. In addition, some evidence suggests that cholesterol-lowering medications, including widely prescribed drugs called statins, may reduce the risk of Alzheimer\'s.

However, in a recent study that followed elderly participants who did not have dementia for six years, people who ate high levels of total fat, saturated fat, trans fat and cholesterol were not more likely to develop dementia than people who ate less fat.

And scientists from Columbia University in New York report that high intake of antioxidant vitamins E, C, and carotenes, which help rid the body of damaging free-radicals linked to Alzheimer\'s, did nothing to reduce risk of the disease.

In contrast, there is solid evidence linking the risk of high intake of certain fats to heart disease. Researchers have shown that saturated fat can boost levels of low-density lipoprotein (LDL), the so-called \\\"bad\\\" form of cholesterol that can cause arteries to become clogged. Other dangerous forms of fat include unsaturated fats that have become partially hydrogenated by manufacturers to make them more stable and solid. Recent evidence suggests that these \\\"trans fats\\\" may be as bad for the heart as saturated fat.

As a rule, even if foods do not include trans fat content on their label, any products that contain partially hydrogenated oils also contain trans fats. Trans fats may be found in margarine, baked goods and other processed foods, and they are often used by restaurants for frying. In contrast, unhydrogenated, unsaturated fats found in vegetable oils such as olive oil and corn oil, appear to improve health.

All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.