Prevention of Alzheimer's Disease: Brief summaries of research reports

Diet & supplements

Vitamin E or C does not reduce risk of dementia or Alzheimer's

Why fish oil is good for you

Healthy diet lowers risk of dementia

Low dose aspirin does not protect women against cognitive decline

Higher level of certain fatty acid associated with lower dementia risk

Omega-3 fatty acids may slow cognitive decline in some patients with very mild Alzheimer's disease

Cabernet sauvignon red wine reduces the risk of Alzheimer's disease

Juices may reduce Alzheimer's disease risk

Calorie restriction may help prevent Alzheimer's

Apples fight memory loss

Dietary supplements offer new hope for Alzheimer's patients

Blackcurrants may protect against Alzheimer's

Folates more effective in limiting Alzheimer's disease risk than antioxidants, other nutrients

Fish oil may help prevent Alzheimer's

Fewer calories may slow Alzheimer's

Compound in apples may help fight Alzheimer's disease

Tea may protect against Alzheimer’s

Omega-3 fatty acid may prevent Alzheimer's disease and slow its progression

Why diet, hormones, exercise might delay Alzheimer’s

Using vitamin E and C supplements together may reduce risk of Alzheimer's

High-dose vitamin regime may help slow Alzheimer's

Common painkillers may help protect against Alzheimer's

Drinking wine may lower risk of dementia

Eating fish cuts risk of dementia

Regular long-term use of aspirin may reduce the risk of Alzheimer’s

Diet rich in foods with Vitamin E may reduce Alzheimer’s disease risk

Folic acid possibly a key factor in preventing Alzheimer's disease

February 2008

Vitamin E or C does not reduce risk of dementia or Alzheimer's

A five-year study involving nearly 3000 people has found that use of Vitamin C or E or both was not associated with a reduced risk of developing dementia or Alzheimer’s.
The study was published in the February issue of the Journal of the American Geriatrics Society. Full reference
http://www.eurekalert.org/pub_releases/2008-02/bpl-veo020408.php

December 2007

Why fish oil is good for you

Confirming previous research indicating that fish oil helps delay or prevent Alzheimer’s, a new study shows why. The study reveals that the omega-3 fatty acid DHA found in fish oil increases the production of LR11, a protein that is found at reduced levels in Alzheimer's patients and which is known to destroy the protein that forms the "plaques" associated with the disease. The study looked at both rodent brains and human brain cells. Still to be determined is what the optimal dose should be.
The report appeared in the December 26 issue of the Journal of Neuroscience.  Full reference
http://www.eurekalert.org/pub_releases/2007-12/uoc--wfo122107.php

November 2007

Healthy diet lowers risk of dementia

A very large study of older adults has found that those who regularly consumed omega-3 rich oils, such as canola oil, flaxseed oil and walnut oil, reduced their risk of dementia by 60% compared to people who did not regularly consume such oils. People who ate fruits and vegetables daily also reduced their risk of dementia by 30% compared to those who didn’t regularly eat fruits and vegetables. Additionally, those who ate fish at least once a week had a 35% lower risk of Alzheimer’s and a 40% lower risk of dementia, but only if they did not carry ApoE4 gene. And finally, the study found those who didn’t have the gene but consumed an unbalanced diet characterized by regular use of omega-6 rich oils, but not omega-3 rich oils or fish, were twice as likely to develop dementia compared to those who didn’t eat omega-6 rich oils, which include sunflower or grape seed oil. The study did not find any association between consuming corn oil, peanut oil, lard, meat or wine and lowering risk of dementia.
The study was published in the November 13 issue of Neurology.  Full reference
http://www.eurekalert.org/pub_releases/2007-11/aaon-efo110607.php

April 2007

Low dose aspirin does not protect women against cognitive decline

Evidence that aspirin and other anti-inflammatory drugs may protect against dementia has been inconclusive. Now a large, long-running study involving 6,377 women aged 65 years or more, over ten years, has found that those who took low dose aspirin (100 mg on alternate days) performed at similar levels to a placebo group on cognitive tests. However, there was evidence of benefit in one very specific area of cognition: category fluency.
The results appeared in the May issue of the British Medical Journal. Full reference
Full text is available at http://tinyurl.com/25kzxf
http://www.eurekalert.org/pub_releases/2007-04/bmj-lda042607.htm

November 2006

Higher level of certain fatty acid associated with lower dementia risk

A nine year study of 899 participants in the Framingham Heart Study (average age 76 years) has found that those with the highest levels of an omega-3 polyunsaturated fatty acid known as docosahexaenoic acid (DHA) had a 47% lower risk of developing dementia and 39% lower risk of developing Alzheimer's. Among the participants who completed the dietary questionnaire, those in this top quartile of blood DHA levels reported that they ate an average of .18 grams of DHA a day and an average of three fish servings a week. Those in the other quartiles ate substantially less fish.
The report appeared in the November issue of Archives of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2006-11/jaaj-hlo110906.htm

October 2006

Omega-3 fatty acids may slow cognitive decline in some patients with very mild Alzheimer's disease

Several studies have shown that eating fish, which is high in omega-3 fatty acids, may protect against Alzheimer's disease. A Swedish study has now tested whether supplements could have similar effects. Patients with mild-to-moderate Alzheimer’s who took 1.7 grams of DHA and .6g of EPA showed the same rate of cognitive decline as those taking a placebo, however, among a subgroup of 32 patients with very mild cognitive impairment, those who took the fatty acids experienced less decline in six months compared with those who took placebo. It may be that anti-inflammatory effects are an important reason for the benefit, potentially explaining why effects were seen only in those with very early-stage disease, when levels of inflammation seem to be higher.
The study was published in the October issue of Archives of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2006-10/jaaj-ofa100506.htm

Cabernet sauvignon red wine reduces the risk of Alzheimer's disease

A mouse study has found moderate consumption of the red wine Cabernet Sauvignon significantly reduced Alzheimer’s-type deterioration of spatial memory function. The Cabernet Sauvignon used contained a very low content of resveratrol, 10-fold lower than the minimal effective concentration shown to promote Aß clearance in vitro. It is suggested that, instead, the benefit occurred through promoting non-amyloidogenic processing of amyloid precursor protein. The finding supports epidemiological evidence indicating that moderate wine consumption (one drink per day for women and two for men) may help reduce the relative risk for Alzheimer’s.
The study was presented at the annual Society for Neuroscience Meeting held in Atlanta, Georgia, October 14-18, and will be published in the November issue of The FASEB Journal. Full reference
http://www.eurekalert.org/pub_releases/2006-09/tmsh-csr091806.htm

August 2006

Juices may reduce Alzheimer's disease risk

In a large epidemiological study, that followed 1836 Seattle residents for up to 10 years, it was found that those who drank three or more servings of fruit and vegetable juices per week had a 76% lower risk of developing Alzheimer’s disease than those who drank juice less than once a week. The benefit seemed greatest for those who carried the so-called “Alzheimer’s gene”. Previously, researchers suspected that antioxidant vitamins (vitamins C, E and -carotene) might help protect against Alzheimer's disease, but this has not been supported in recent clinical studies. Another class of antioxidant chemicals, polyphenols, are now suspected. Polyphenols generally exist primarily in the skins of fruits and vegetables and are particularly abundant in teas, juices and wines.
The report appears in the September issue of The American Journal of Medicine. Full reference
http://www.eurekalert.org/pub_releases/2006-08/vumc-jmr082806.htm
http://www.eurekalert.org/pub_releases/2006-08/ehs-ssf082806.htm

July 2006

Calorie restriction may help prevent Alzheimer's

A mouse study has found that beta-amyloid peptides can be reduced by restricting calorie intake, primarily through a low carbohydrate diet. Conversely, a high caloric intake based on saturated fat was shown to increase levels of beta-amyloid peptides. This is the first study to suggest that caloric restriction might inhibit the generation of beta-amyloid peptides, but there have been a number of studies providing evidence that high cholesterol, obesity, and other cardiovascular risk factors increase the likelihood of Alzheimer’s.
The study appeared in the August 4 issue of the Journal of Biological Chemistry. Full reference
http://www.sciencedaily.com/releases/2006/06/060614113128.htm

Apples fight memory loss

The study involved adult and old mice (some engineered to develop Alzheimer's-like symptoms) being fed either a standard diet, a nutrient-deficient diet, or a nutrient-deficient diet supplemented with apple juice concentrate. The mice on the apple juice-supplemented diet showed an increased production of acetylcholine in their brains and performed significantly better on maze tests. The amount of consumption was comparable to humans drinking approximately two 8 oz. glasses of apple juice or eating 2-3 apples a day. The findings also suggest that the apple-supplemented diet was most helpful in the framework of an overall healthy diet. Acetylcholine levels declined in both adult and old mice on the nutrient-deficient diet.
The study was published in the August issue of the Journal of Alzheimer's Disease. Full reference
http://www.sciencedaily.com/releases/2006/08/060801225922.htm

April 2006

Dietary supplements offer new hope for Alzheimer's patients

A "cocktail" of dietary supplements (omega-3 fatty acids, uridine and choline) has been found to dramatically increase the amount of membranes that form brain cell synapses in gerbils. The treatment is now in human clinical trials. It is hoped that such treatment may significantly delay Alzheimer's disease. The treatment offers a different approach from the traditional tactic of targeting amyloid plaques and tangles. Choline can be found in meats, nuts and eggs, and omega-3 fatty acids are found in a variety of sources, including fish, eggs, flaxseed and meat from grass-fed animals. Uridine, which is found in RNA and produced by the liver and kidney, is not obtained from the diet, although it is found in human breast milk.
The study appears in the May 9 issue of Brain Research. Full reference
http://www.eurekalert.org/pub_releases/2006-04/miot-mro042706.htm

January 2006

Blackcurrants may protect against Alzheimer's

A cultured cell study has found that compounds in blackcurrants strongly protect neuronal cells against the types of stress caused by dopamine and amyloid-b, a peptide associated with Alzheimer's disease. Blackcurrants and boysenberries also contain anthocyanins and polyphenolics. Those that are darker (like British blackcurrants) have more anthocyanins and are likely to be more potent. Compounds from these berries are already known to act as antioxidants, but a role in neuroprotection has not been demonstrated previously.
The paper was published online 23 January and will appear in a forthcoming issue of the Journal of the Science of Food and Agriculture. Full reference
http://www.eurekalert.org/pub_releases/2006-01/jws-bbb011906.htm

August 2005

Folates more effective in limiting Alzheimer's disease risk than antioxidants, other nutrients

Analysis of data from the Baltimore Longitudinal Study of Aging has revealed that those with higher intake of folates, vitamin E and vitamin B6 had a lower risk of developing Alzheimer’s. When the three vitamins were analyzed together, only folates were associated with a significantly decreased risk. Those who had at least 400mcg of folates a day (the recommended daily allowance) had a 55% reduction in risk of developing Alzheimer’s. Unfortunately, most people who reached that level did so by taking supplements, suggesting the difficulty of doing so through diet alone. Folates are abundant in foods such as liver, kidneys, yeast, fruits (like bananas and oranges), leafy vegetables, whole-wheat bread, lima beans, eggs and milk; however, they are often destroyed by cooking or processing. No association was found between vitamin C, carotenoids (such as beta-carotene) or vitamin B-12 intake and decreased Alzheimer's risk.
Results appear in the inaugural issue of Alzheimer's & Dementia: The Journal of the Alzheimer's Association. Full reference
http://www.eurekalert.org/pub_releases/2005-08/uoc--fme081105.htm

March 2005

Fish oil may help prevent Alzheimer's

A study involving genetically engineered mice has found that a diet high in docosahexenoic acid, or DHA — an omega-3 fatty acid found in relatively high concentrations in cold-water fish — dramatically slowed the progression of Alzheimer's, by cutting the harmful brain plaques that mark the disease. An earlier study showed that DHA protected against damage to the "synaptic" areas where brain cells communicate and enabled mice to perform better on memory tests. Food sources of omega-3 fatty acids include fish such as salmon, halibut, mackerel and sardines, as well as almonds, walnuts, soy, and DHA-enriched eggs.
The results appear in the March 23 online edition of the Journal of Neuroscience. Full reference
http://www.eurekalert.org/pub_releases/2005-03/vrcs-foh032405.htm

December 2004

Fewer calories may slow Alzheimer's

Restricting the diets of genetically engineered mice by 40% over 4 weeks reduced the build-up of plaques in the brain that are linked to Alzheimer's disease by 50%. It remains to be seen whether such dietary changes would similarly affect humans. Researchers are now looking to isolate the specific factors of the diet restriction which are important.
The study was published 25 November in the online version of Neurobiology of Aging. Full reference
http://www.eurekalert.org/pub_releases/2004-12/uosc-fcm121404.htm

November 2004

Compound in apples may help fight Alzheimer's disease

Researchers are recommending that apples may be a particularly beneficial food to protect against Alzheimer’s. A study that exposed groups of isolated rat brain cells to varying concentrations of either quercetin or vitamin C supports the theory that quercetin protects against cellular damage. A particularly good source of quercetin is apples — mainly in the skin. In general, red apples tend to have more of the antioxidant than green or yellow ones. Other foods containing high levels of quercetin include onions, which have some of the highest levels of quercetin among vegetables, as well as berries, particularly blueberries and cranberries.
The study appeared in the December 1 issue of the Journal of Agricultural and Food Chemistry.
http://www.eurekalert.org/pub_releases/2004-11/acs-ia111604.htm

October 2004

Tea may protect against Alzheimer’s

A study investigating the properties of coffee and green and black tea has found that both green and black tea inhibited the activity of enzymes associated with the development of Alzheimer's Disease (acetylcholinesterase and butyrylcholinesterase), but coffee had no significant effect. Green tea also obstructed the activity of beta-secretase, which plays a role in the production of protein deposits in the brain which are associated with Alzheimer's disease, and continued to have its inhibitive effect for a week, whereas black tea's enzyme-inhibiting properties lasted for only one day.
The findings are published in the August issue of Phytotherapy Research. Full reference
http://www.eurekalert.org/pub_releases/2004-10/uonu-tci102504.htm

September 2004

Omega-3 fatty acid may prevent Alzheimer's disease and slow its progression

A study using genetically engineered mice has shown that a diet high in the omega-3 fatty acid DHA helps protect the brain against the memory loss and cell damage caused by Alzheimer's disease. Cheap sources of DHA include coldwater fish, like salmon, halibut, mackerel, sardines and herring. These fish consume algae, which is high in DHA. Because these fishes' oiliness makes them absorb more mercury, dioxin, PCP and other metals, however, a less risky yet more costly strategy is to consume fish oil or purified DHA supplements made from algae. Other options include DHA-rich eggs laid by chickens that eat DHA-supplemented feed.
The paper appeared in the September 2 issue of Neuron.
http://www.eurekalert.org/pub_releases/2004-09/uoc--ddp082604.htm

February 2004

Why diet, hormones, exercise might delay Alzheimer’s

A theory that changes in fat metabolism in the membranes of nerve cells play a role in Alzheimer's has been supported in a recent study. The study found significantly higher levels of ceramide and cholesterol in the middle frontal gyrus of Alzheimer's patients. The researchers suggest that alterations in fats (especially cholesterol and ceramide) may contribute to a "neurodegenerative cascade" that destroys neurons in Alzheimer's, and that the accumulation of ceramide and cholesterol is triggered by the oxidative stress brought on by the presence of the toxic beta amyloid peptide. The study also suggests a reason for why antioxidants such as vitamin E might delay the onset of Alzheimer's: treatment with Vitamin E reduced the levels of ceramide and cholesterol, resulting in "a significant decrease in the number of neurons killed by the beta amyloid and oxidative stress.
The study was published in the February 17 issue of Proceedings of the National Academy of Sciences. Full reference
http://www.eurekalert.org/pub_releases/2004-02/aaft-nsm021004.htm

January 2004

Using vitamin E and C supplements together may reduce risk of Alzheimer's

A study involving 4,740 elderly (65 years or older) found the greatest reduction in both prevalence and incidence of Alzheimer's in those who used individual vitamin E and C supplements in combination, with or without an additional multivitamin. There was no significant benefit in using vitamin C alone, vitamin E alone, or vitamin C and multivitamins in combination.
The study appeared in the January issue of the Archives of Neurology. Full reference http://www.eurekalert.org/pub_releases/2004-01/jaaj-uve011404.htm

March 2003

High-dose vitamin regime may help slow Alzheimer's

A preliminary study suggests that a regime of high doses of folic acid, B12 and B6 reduces levels of homocysteine in people with mild to moderate Alzheimer’s. A larger study, recruiting 400 participants from all over the U.S., is to be undertaken to assess whether such a vitamin regime can slow the progression of Alzheimer's disease. In the meantime, it is not advised that people take high doses of these vitamins, as there are possible side-effects, including peripheral nerve damage.
The report was published in the March /April issue of the American Journal of Geriatric Psychiatry.
Full reference
http://www.eurekalert.org/pub_releases/2003-03/gumc-cvs031403.htm

Common painkillers may help protect against Alzheimer’s disease

Observations that people who take anti-inflammatory medications over several years have a lower risk of later developing Alzheimer's disease have received support from an exciting new study which has revealed that common over-the-counter pain medications (such as ibuprofen and naproxen) bind to amyloid plaques, and may help dissolve existing plaques and prevent the formation of new ones. Amyloid plaques are one of the definitive hallmarks of Alzheimer's disease.
The findings are reported in the March 31 issue of Neuroscience. Full reference
http://www.eurekalert.org/pub_releases/2003-03/uoc--urd031203.htm

November 2002

Drinking wine may lower risk of dementia

Researchers in Copenhagen have followed up an analysis of drinking patterns for wine, beer and liquor of 1,709 people in the 1970s with an assessment of dementia in the 1990s, when participants were age 65 or older. 83 of the participants had developed dementia. Their alcohol intake was compared to that of those who did not develop dementia. It was found that those who drank wine occasionally had a lower risk of developing dementia, including Alzheimer's disease. Those who drank wine every day were no more or less likely to develop dementia than those who drank it less often. The study also found that occasional beer drinking was associated with an increased risk of developing dementia. It is important to note that eating habits were not investigated, and research suggests that wine drinkers may have better dietary habits than beer and liquor drinkers.
The study was published in the November 12 issue of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2002-11/aaon-dwm110702.htm

October 2002

Eating fish cuts risk of dementia

Using data from a French epidemiological study of cognitive and functional aging, researchers found that those who ate fish or seafood at least once a week had a significantly lower risk of being diagnosed as having dementia (including Alzheimer’s) over the seven years follow-up. This confirms earlier findings from the Rotterdam Study, which had a much shorter follow-up (a mean of 2.1 years). There was an association between level of education and diet which partly, but not completely, explains this. It does appear that this is a benefit from eating fish / seafood, possibly from the fatty acids found in fish oils. There was no significant association between meat consumption and risk of dementia.
The study appeared in the October 26 issue of the British Medical Journal (BMJ).Full reference
http://www.eurekalert.org/pub_releases/2002-10/bmj-efc102302.htm

September 2002

Regular long-term use of aspirin may reduce the risk of Alzheimer’s

A large-scale study of 5,092 older adults has found that regular use of aspirin and other non-steroidal anti-inflammatory drugs may reduce the incidence of dementia in elderly people, but only when taken for more than two years, and provided the use occurred well before the onset of dementia.
The study was reported in the September 24 issue of Neurology.Full reference
http://www.eurekalert.org/pub_releases/2002-09/aaon-get091702.htm

June 2002

Diet rich in foods with Vitamin E may reduce Alzheimer’s disease risk

Two studies have come out in favor of a diet rich in foods containing vitamin E to help protect against Alzheimer's disease. One study involved 815 Chicago residents age 65 and older with no initial symptoms of mental decline, who were questioned about their eating habits and followed for an average of about four years. When factors like age and education were taken into account, those eating the most vitamin E-rich foods had a lower risk of developing Alzheimer’s, provided they did not have the ApoE e4 allele. This was not true when vitamin E was taken as a supplement. Intake of vitamin C and beta carotene appeared protective, but not at a statistically significant level. The other study involved 5,395 people in the Netherlands age 55 and older who were followed for an average of six years. Those with high intakes of vitamins E and C were less likely to become afflicted with Alzheimer's, regardless of whether they had the gene variation. This association was most pronounced for current smokers, for whom beta carotene also seemed to be protective. A number of clinical trials are underway to further investigate these links.
The study appeared in the June 26 issue of the Journal of the American Medical Association (JAMA). Full reference 2
http://www.eurekalert.org/pub_releases/2002-06/nioa-dri062102.htm
http://www.eurekalert.org/pub_releases/2002-06/pn-tsr062702.htm

March 2002

Folic acid possibly a key factor in preventing Alzheimer's disease

Experiments with mice bred with mutant genes that cause Alzheimer's disease found that those mice fed on a diet deficient in folate had fewer neurons in the hippocampus ( a brain region critical for learning and memory that is destroyed as plaques accumulate during Alzheimer’s disease), and elevated levels of homocysteine. Researchers suspect that increased levels of homocysteine in the brain caused damage to the DNA of nerve cells in the hippocampus. In the mice fed an adequate amount of folate, nerve cells in this brain region were able to repair the damage. But in those mice fed a folate-deficient diet, nerve cells were unable to repair this damage. A human study is being planned.
Green leafy vegetables, citrus fruits and juices, whole wheat bread and dry beans are good sources of folate. In the U.S., since 1998, the Food and Drug Administration has required the addition of folic acid to enriched breads, cereals, flours, corn meals, pastas, rice, and other grain products.
The study was published in the March 1 issue of the Journal of Neuroscience. Full reference
http://www.eurekalert.org/pub_releases/2002-03/nioa-fap030102.htm

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