More on DHA and Alzheimer’s disease Readers of Life Extension Update may recall the September 4 2004 issue which reported the findings of Greg Cole and colleagues at UCLA on the protective benefit of docosahexaenoic acid (DHA) against Alzheimer’s disease, published in the journal Neuron. Now, the March 23 2005 online edition of the Journal of Neuroscience reports further research of Dr Cole which confirms the findings of the previous experiments.
DHA is an omega-3 fatty acid found in fish oil and algae whose consumption has been associated with a reduction in inflammation and the risk of cardiovascular disease as well as other conditions.
Using older mice bred to develop the beta-amyloid plaques that are characteristic of the brains of Alzheimer’s disease patients, the team provided them with diets that consisted of no DHA, a “normal” (control) level of the fatty acid, or a high amount. The mice, who were 17 to 19 months old at the beginning of the study, consumed the diets until the age of 22 and one half, after which their brains were examined for beta-amyloid and plaque formation.
Dr Cole and colleagues discovered that the mice who received the high DHA diet had 70 percent less beta-amyloid in their brains than the mice who received no DHA or the control diet. Overall plaque burden was 40 percent less in the mice receiving the DHA enriched diet, with the largest reductions observed in the parietal cortex and hippocampus.
Dr Cole, who is the associate director for research at the Los Angeles Veteran Administration's Geriatric Research, Education and Clinical Center, and a professor at the David Geffen School of Medicine at UCLA, stated, "The good news from this study is that we can buy the therapy at a supermarket or drug store. DHA has a tremendous safety profile--essentially no side effects--and clinical trial evidence supports giving DHA supplements to people at risk for cardiovascular disease."
Alzheimer’s disease In Alzheimer's disease, an inflammatory cascade begins in response to beta-amyloid. The inflammatory response, involving cytokines and prostaglandins, occurs around beta-amyloid in the neuron. This inflammatory process continues and accelerates the loss of neurons.
Inflammation is a protective response of the body that occurs during the process of repair. The four cardinal signs of inflammation are redness, swelling, heat, and pain. The Russian biologist Elie Metchnikoff proposed that the purpose of inflammation was to bring phagocytotic cells to the injured area in order to engulf invading bacteria. Both Metchnikoff and Paul Ehrlich (who developed the humoral theory of immunity) shared the Nobel Prize in 1908.
Inflammation is considered to be an underlying cause of Alzheimer's disease, primarily because beta-amyloid is an inflammatory protein (Hull 1996; McGeer et al. 1999).
A Japanese study of 64 patients with Alzheimer's disease and 80 age-matched healthy adults found that the dietary behaviors of Alzheimer's disease patients were markedly different. The Alzheimer's disease patients tended to dislike fish and green-yellow vegetables and took more meats than controls. Nutrient analysis revealed that Alzheimer's disease patients took less vitamin C and carotene and consumed significantly smaller amounts of omega-3 polyunsaturated fatty acids (PUFAs) reflecting the low consumption of fish. These habits started from three months to 44 years before the onset of dementia, suggesting these dietary abnormalities are not merely the consequence of dementia (Otsuka 2000).
Curcumin, the active ingredient in the herb turmeric, is being investigated for use in Alzheimer's disease due to its potent anti-inflammatory action (Joe 1997; Grilli 1999).
As people age, chronic systemic inflammation can inflict degenerative effects throughout the body. A primary cause of this destructive cascade is the production of cell-signaling chemicals known as inflammatory cytokines. Along with these dangerous cytokines, imbalances of hormone-like messengers called prostaglandins also contribute to chronic inflammatory processes.
Life Extension has uncovered research that shows the addition of sesame lignans to fish oil enhances its beneficial effects. When fats are consumed, they are broken down into factors that either promote or suppress inflammatory reactions. Specialized enzymes in the body determine which inflammatory pathway fats will follow. Sesame lignans inhibit an enzyme (delta-5 desaturase) that causes dietary fats to be converted into arachidonic acid, a precursor to the toxic inflammatory factors prostaglandin E2 and leukotriene B4.
Curcumin was first used by Indians over 3000 years ago in traditional Ayurvedic medicine. Modern science has found that this extract from the common spice turmeric has remarkable qualities as an antioxidant. Over time, as our cells continue to be affected by free radicals, or oxidants, organs begin to degenerate and aging accelerates.
The body does have built-in defense mechanisms to protect itself from free radical damage, but eventually, aging and disease deplete the body’s ability to keep oxidants at bay.
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