A diet high in calories and fat may increase the risk of Alzheimer's disease in people who are genetically susceptible to the mind-robbing disorder, new research suggests. The study found that people who consumed the most calories and fat faced double the risk of developing Alzheimer's.
The findings, which are reported in this month's Archives of Neurology, are the latest evidence that lifestyle factors including diet may play a role in Alzheimer's. Some researchers believe that restricting calories may slow the aging process by reducing production of cell-damaging oxygen molecules called free radicals, formed during the body's breakdown of food.
The latest study, though preliminary, suggests that for some people, calorie restriction might lower Alzheimer's risks by curbing nerve-cell death in the brain. Lead author Dr. Jose Luchsinger, an Alzheimer's researcher at Columbia University, said it would be premature to recommend specific diets for reducing Alzheimer's risks.
Study participants whose diets increased the risk had one or two copies of the apolipoprotein-E gene variant known as apoE e-4. People with the e-4 variant are thought to be already prone to the disease. About 20 percent of the U.S. population has one copy and even fewer have two, said William Thies, vice president of medical and scientific affairs for the Alzheimer's Association. In the study, 28 percent of participants had one or two copies of the variant. The gene is involved in transporting cholesterol in the blood. Not everyone with the e-4 variant develops the disease, and the study suggests that diet may influence which people with the variant become afflicted, Thies said.
A study published in the same journal earlier this year linked high cholesterol levels with Alzheimer's and suggested that cholesterol-lowering drugs could reduce the risk. That research did not examine whether a low-fat diet would achieve the same results. The new study involved 980 Medicare patients aged 75 on average in New York who were asked to recall their food intake during the first year of the four-year study. They also underwent annual exams.
Alzheimer's was diagnosed during the study in 242 people. Patients with the gene variant who reported the highest consumption of fats and calories faced double the risk of developing Alzheimer's, compared with those who reported the lowest amounts. Because the average reported daily amounts were quite low; about 1,300 calories and 38 grams of fat. Luchsinger said the overall trend is much more significant than the actual amounts. The lowest reported amounts, about 758 calories daily and 16 grams of fat, likely would be considered unhealthful for many people and should not be used as a blueprint for avoiding Alzheimer's, he said. Luchsinger said it's possible that some participants had faulty memories and inaccurately reported their food intake, while others may have even started developing undetected Alzheimer's that could have influenced their memories or food choices. Still, he said the study ``certainly points in a direction'' favoring the diet theory. Thies said the findings suggest fats may play some sort of role in Alzheimer's that needs more study. But he also said the study is in line with general recommendations for a healthy diet which means avoiding overeating and too many fat-rich foods.
For even more information check out these web sites: