Connection between Molecules Involved in Early- and Late-Onset Alzheimer’s Discovered

Researchers at Washington University School of Medicine in St. Louis found an aspect of cholesterol transport and metabolism in the brain that links molecules involved in early- and late-onset Alzheimer’s disease (Neuron, October 1, 2007, see NoL noteworthy colelction).

The scientists believe that their study strengthens the case for another cause of Alzheimer’s besides build up of amyloid-beta (A-beta) plaques. “Cholesterol metabolism in the brain is an understudied area, and our findings could inspire Alzheimer’s researchers to look further into the role of the cholesterol pathway,” says senior author Guojun Bu, Ph.D., professor of pediatrics and cell biology and physiology.

Early-onset Alzheimer’s can be traced to mutations in one of three genes including the gene coding for A-beta’s precursor, APP. The genetic origins of late-onset Alzheimer’s are unknown, but studies have shown that a particular mutation in the gene for a cholesterol carrier, called apolipoprotein E, increases risk.

The Washington University team report that when APP is cleaved by gamma-secretase in the brain, it releases A-beta plus a small protein fragment, APP intracellular domain (AICD). AICD regulates apolipoprotein E, which moves cholesterol in the brain from support cells to neurons, through the lipoprotein receptor LRP1.

“Right now,” Dr. Bu adds, “research on Alzheimer’s treatment focuses largely on reducing A-beta production or increasing its clearance from the brain. Our study suggests that there could be an alternate way to treat the disease, perhaps by modulating the function of apolipoprotein E and cholesterol in the brain.”

Source: Connection between Molecules Involved in Early- and Late-Onset Alzheimer’s Discovered. GEN News Highlights (5 October 2007) [FullText]

Brain, Eye and Heart Health: Three Reasons to Eat More Omega-3s

DENVER, 3 October 2007 (PRNewswire) - Most pregnant women consuming a typical western diet obtain too little DHA (docosahexaenoic acid), a major marine omega-3 fatty acid, which is critical for fetal and infant brain development. This was the conclusion of a landmark report from an international panel of nutrition experts summarized in the September 2007 Fats of Life and PUFA Newsletter electronic publications. The report called for pregnant and lactating women to consume at least 200 mg of DHA/day. It also noted that higher maternal intakes of DHA are linked to better visual acuity, cognitive function, sleep patterns and other benefits.

Another study discussed in the e-newsletters found that mothers at high-risk of preterm delivery may lower their chance of giving birth early by increasing their intake of marine omega-3s. Moreover, the breast milk content of DHA in mothers from around the world was the lowest in countries where little fish is consumed, such as the U.S. and Canada.

"Many, if not most, women are not consuming enough DHA," said Joyce Nettleton, DSc, editor of Fats of Life and the PUFA Newsletter. "This is especially true in western countries."

Seeing is believing when it comes to marine omega-3s and eye health. A US study revealed that animals at risk of retinal damage were better protected from vision loss if they consumed diets high in marine omega-3s.

Other recent research reported that a key region of the brain affected by mood disorders has significantly less DHA in people suffering from major depression compared with those who are not depressed. There is also new evidence that cognitive function in later life may be partly protected when marine omega-3s are more abundant.

Finally, the e-newsletters report that DHA, along with the omega-3 EPA (eicosapentaenoic acid), enhances the effectiveness of statin drugs in patients with high cholesterol and triglycerides by lowering triglycerides significantly, according to an Australian study. Statins alone have little effect on triglyceride levels.

The bottom line: boosting one's marine omega-3 intake may improve brain development and function and protect the eyes and heart from disease damage. Learn more in the latest issues of the quarterly Fats of Life e-newsletter and PUFA Newsletter. These publications, sponsored by DSM Nutritional Products, are online at www.fatsoflife.com and by complimentary subscription.

Source: Fats of Life, Source: PR Newswire (3 October 2007) [FullText]