Turmeric's yellow pigment seen to retard Alzheimer's in animals; fish fat yields similar preventive effects
by Craig Weatherby
If we say you should try some curry on the brain, it doesn't mean we're advocating the bizarre culinary behavior of movie villain Hannibal “the cannibal” Lecter.
It's just that turmeric—the bright-yellow constituent in curry spice blends—appears to be one of the most promising anti-Alzheimer's foods yet found.
And, as with cancer, it looks as though turmeric and the omega-3 fatty acids in fish oil are close competitors when it comes to brain health.
Alzheimer's disease (AD) is characterized by formation of plaques that consist of inflammation-inducing proteins called beta-amyloid, which also form wiry tangles called fibrils.
No one is yet certain whether amyloid plaques and fibrils cause or result from the still-mysterious process that leads to AD. But it is certain that amyloid plaques and fibrils accompany AD symptoms, and that drugs and dietary factors that inhibit inflammation, oxidation, and formation of amyloid plaques and fibrils also reduce AD symptoms.
Accordingly, many researchers have been testing the effects of curcumin against these AD-promoting factors, with great success.
As UCLA researchers put it last year, in their summary of a successful study of the effects of curcumin in the brain tissue of rodents with AD (Yang F, 2005), “Alzheimer's disease (AD) involves amyloid beta (Abeta) accumulation, oxidative [free radical] damage, and inflammation, and risk is reduced with increased antioxidant and anti-inflammatory consumption. The phenolic yellow curry pigment curcumin has potent anti-inflammatory and antioxidant activities and can suppress oxidative damage, inflammation, cognitive deficits, and amyloid accumulation.”
And their results were very good, showing that formation of amyloid plaques and fibrils was substantially prevented—and existing plaques and fibrils were broken up—in AD-afflicted mice fed curcumin:
- “When fed to aged… mice with advanced amyloid accumulation, curcumin labeled [bound to] plaques and reduced amyloid levels and plaque burden.
- “Hence, curcumin directly binds small beta-amyloid species [proteins] to block aggregation [of amyloid into plaque] and fibril formation in vitro [test tubes] and in vivo [animals].
- “These data suggest that low dose curcumin effectively disaggregates [breaks up] Abeta [amyloid protein] as well as prevents fibril and oligomer [amyloid chain] formation, supporting the rationale for curcumin use in clinical trials preventing or treating AD.”
This and other studies show that curcumin is far more effective against amyloid formation, compared with antiinflammatory drugs like aspirin and ibuprofen.
This is probably because, as they put it, “the yellow pigment in turmeric… [targets] multiple AD pathogenic cascades.” If this sounds familiar, it's because you read our companion article on the anti-cancer effects of turmeric, whose potency researchers attribute to curcumin's ability to attack the disease from several angles at once (see "Turmeric Power, Part I: Colorful Spice Seen to Combat Cancer").
So far, all of the research has occurred in cells and test animals, but the results have been so encouraging that UCLA researchers are proceeding to raise funds for human clinical trials.
Fish fat proves feisty AD-fighter
The same group of UCLA researchers cited above, who've done much of the U.S. work on curcumin and AD, published intriguing results late last year (Cole GM, 2005). This time their work was conducted at the Veterans' Research, Education and Clinical Center in Sepulveda, California.
They found that while non-steroidal anti-inflammatory drugs like ibuprofen could reduce accumulation of amyloid plaque, they suppressed few inflammatory markers, did not reduce oxidative damage, and presented safety concerns.
This time, they tested the effects of dietary curcumin and DHA—one of the two main omega-3 fatty acids in fish fat—in mice, and found both food factors highly effective. As they said, “The dietary omega-3 fatty acid, docosahexaenoic acid (DHA), also limited amyloid, oxidative damage and synaptic and cognitive deficits in [mice]. Both DHA and curcumin have favorable safety profiles, epidemiology [population study results] and efficacy, and may exert general anti-aging benefits (anti-cancer and cardioprotective).”
Conked on the head? Eat fish, take turmeric
The findings from two recent animal studies indicate that the curcumin fraction of turmeric can help prevent brain damage resulting from a blow to the head.
In a study published this month (Wu A 2006), rats were fed a regular diet or a diet high in saturated fat, with or without curcumin, for four weeks, and were then given a mild blow to the head. After being conked on the noggin, the rats fed a high-fat diet suffered a loss of cognitive functioning, but the ones that had been eating curcumin had much less oxidative damage to their brains, and it seemed to counteract the cognitive impairment caused by the conk on the head.
And in an almost identical study published two years ago by the same team (Wu A, 2004), mice fed fish oil before being conked on the head enjoyed similar protection from the ill effects of head trauma. As the authors said, “These results imply that omega-3 enriched dietary supplements can provide protection against reduced plasticity and impaired learning ability after traumatic brain injury.”
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