Roughly 5.1 million Americans have Alzheimer's disease; that number is expected to grow to 7.7 million by 2030. But two studies have identified therapies that may help keep the devastating - and often fatal - deterioration of the brain that characterizes Alzheimer's at bay.
First, scientists at the University of California at Irvine have reported that omega-3 fatty acids may slow the growth of two distinct brain lesions that are hallmarks of Alzheimer's disease. A study using genetically modified mice is the first to demonstrate that DHA, an omega-3 fatty acid, can delay the development of protein "tangles" in brain cells. DHA also reduces levels of beta amyloid, another protein which can cluster in the brain and form plaques. Mice in a control group ate food that mimics a typical American diet, with a 10 to one ratio of omega-6 fatty acids to omega-3 fatty acids. Studies indicate that a proper ratio is important to maintain health, with the ideal being 3:1 to 5:1.
Mice in three test groups were given food with a 1:1 ratio of omega-6 fatty acids to omega-3 fatty acids. One of these groups received supplemental DHA only. Two groups received DHA, plus additional omega-6 fatty acids. After three months, mice in all of the test groups had lower levels of both proteins than mice in the control group, but at nine months, only mice on the DHA diet had lower levels. These results suggest that DHA works better on its own than when paired with omega-6 fatty acids. The research appeared in the April 18, 2007, issue of The Journal of Neuroscience.
"Perhaps no piece of nutritional advice in the year 2007 is more relevant than this one: to reduce your risk of a wide variety of diseases including heart disease, cancer, diabetes and Alzheimer's, consume more omega-3 fatty acids and fewer omega-six fatty acids," said Dr. Weil. "A good way to do this: add wild-caught fatty fish such as Alaskan salmon to your diet, and reduce consumption of fried food, which tends to be saturated with omega-6-rich soybean oil." Rebalancing the ratios of these fats is an important component of Dr. Weil's anti-inflammatory diet.
Second, you've probably heard before that mentally stimulating activities can reduce the risk of Alzheimer's disease. Now, a new study suggests just how much protection we might expect. Researchers in Chicago found that people who are cognitively active in old age are 2.6 times less likely to develop dementia or Alzheimer's than those who use their heads less. Stimulating activities include such routine habits as reading the newspaper, checking out and reading a library book, as well as playing chess, going to the theater and other mentally engaging pursuits. Investigators from Rush University Medical Center tested more than 700 study participants, average age 80, every year for up to five years. A total of 90 developed Alzheimer's during the study, and risks of getting the disease correlated with levels of mental "workouts". The benefits of mental stimulation held true even after the investigators controlled for past cognitive activity, socioeconomic status throughout life and current social and physical activity. The study was published on June 27, 2007 in the online edition of Neurology, the medical journal of the American Academy of Neurology.
"The research is clear on this issue: challenging your mind on a regular basis helps to lower the risk of developing Alzheimer's disease," said Dr. Weil.
By Brad Lemley