Losing Your Mind for the Sake of a Burger
by Jeff Nelson

Headlines have been made by one, lone review of data in Hawaii, purporting to suggest a relationship between soy consumption and Alzheimer's disease. Major news outlets covered the story, 20/20 jumped on it in its usual tabloid style, and the few big anti-soy sites out there have had a field day sensationalizing it. (I've discussed some problems with this study in a previous article [].)

A 1993 study found that subjects who ate meat, including poultry and fish, were nearly three times as likely to become demented as their vegetarian counterparts.

There is a great deal more compelling research, however, showing that Alzheimers correlates with the consumption of . . . meat and dairy. So why isn't 20/20 and the rest getting this information out?

Between 6 and 8% of the population over 60 has Alzheimer's disease, and the rate has been increasing steadily.

Can we really do anything nutritionally to impact our chances of avoiding this disease? What does the scientific literature have to say about Alzheimers and diet?

Avoid Aluminum

The most striking relationship found in a search of Medline is the association between aluminum and Alzheimer's. The National Library of Medicine shows 488 articles in respected medical journals discussing the link between the metal and the disease. As far back as 1978, scientists reported that Alzheimer's patients' aluminum levels were 1.4 times higher than those in healthy people. [Biol Psychiaty, 13:709-718, 1978] Later studies found that aluminum concentrations were particulaly high in the internal type of neuron lesion, the nerve "tangles." [Ciba Found Symp, 169:217-227, 1992] Another study found that aluminum levels in the blood were three to four times higher in patients with dementia than in healthy volunteers [J Inorg Biochem, 69:171-176, 1998], while yet another reported that hip-fracture patients with Alzheimer's showed signifcantly higher concentrations of aluminum in their bones than did their healthy counterparts. [Actua Orthop Scan, 68:511-512, 1997] This is just a sampling of the hundreds of medical studies demonstrating that high levels of alumninum contribute to Alzheimer's.

The takehome message: don't take chances, avoid aluminum in your diet at all costs -- don't cook with aluminum cookware, avoid baked goods prepared with aluminum-containing baking powders (particularly commercial baked goods), minimize or eliminate other dietary sources of aluminum such as American cheese, chocolate-flavored pudding and beverages in aluminum containers -- and chewing gum. Certain drugs, particularly antacids, contain significant amounts of aluminum, as do many cosmetics. One of the most widely used sources of aluminum are antiperspirants -- avoid deodorants with the active ingredient aluminum chlorohydrate.

Avoid Animal Protein

The next most striking aspect in a review of studies published during the past two years sheds significant light on another central risk factor in Alzheimers -- high levels of a blood substance called homocysteine.

Homocysteine is an amino acid, and amino acids are the building blocks of proteins. The only source of homocysteine for use in our bodies is that which is formed by the liver after the ingestion of another amino acid, methionine. Methionine is found in protein foods -- and animal protein contains two to three times the amount of methionine as does plant protein.

Among recent studies looking at the significance of elevated homocysteine levels and Alzheimer's are:

1)    Miller JW; Homocysteine and Alzheimer's disease. Nutr Rev, 1999 Apr, 57:4, 126-9

"In a recent case-control study of 164 patients with clinically diagnosed Alzheimer's disease (AD), including 76 patients with the AD diagnosis confirmed postmortem, mean total serum homocysteine concentration was found to be significantly higher than that of a control group of elderly individuals with no evidence of cognitive impairment."

2)    Clarke R, et al; Folate, vitamin B12, and serum total homocysteine levels in confirmed Alzheimer disease Arch Neurol, 1998 Nov, 55:11, 1449-55

"Elevated homocysteine levels were associated with Alzheimer's Disease."

3)    McCaddon A, et al; Total serum homocysteine in senile dementia of Alzheimer type Int J Geriatr Psychiatry, 1998 Apr, 13:4, 235-9

"Senile dementia of Alzheimer type patients have significantly elevated homocysteine."

This study, also confirming the link between homocysteine and Alzheimer's, was done in the UK.

4)    Gottfries CG, et al; Early diagnosis of cognitive impairment in the elderly with the focus on Alzheimer's disease. J Neural Transm, 1998, 105:8-9, 773-86

"We found serum-homocysteine to be an early and sensitive marker for cognitive impairment. In patients with dysmentia (mild cognitive impairment), no less than 39% had pathological serum-homocysteine levels."

This study, conducted in Sweden, not only showed blood levels of homocysteine to correlate strongly with Alzheimer's disease -- but showed elevated levels of homocysteine were useful in *predicting* who might get Alzheimer's.

In another study, reported at the World Alzheimer's Congress in July 2000, researches looked at 5,395 individuals aged 55 and over who were free from dementia. After examining subjects in 1993 and again in 1999 researchers reported the following:

"On average, people who remained free from any form of dementia had consumed higher amounts of beta-carotene, vitamin C, vitamin E and vegetables than the people in the study who developed Alzheimer’s disease."

The researchers also noted that in this study, family history or the presence of a genetic marker called the ApoE4 allele (both considered risk factors for Alzheimer's) did not alter their findings. In other words, high consumption of vegetables appeared to offset one of the other known risk factors for Alzheimer's.

So How Can You Lower Your Risk for Alzheimer's?

In addition to avoiding dietary and cosmetic sources of aluminum, maintain a low homocysteine level by greatly reducing consumption of the homocystein- producing amino acid methionine -- through minimizing or avoiding meat and dairy consumption.

And if you're eating one of those high-protein fad diets, just be aware that along with the extra pounds you may temporarily lose, you may just lose your mind, too, by setting the later stage for becoming an Alzheimer's casualty.

We already know from a 1993 study that subjects who ate meat, including poultry and fish, were nearly three times as likely to become demented as their vegetarian counterparts. [Neuroepidemiology, 12:28-36, 1993]

Another recent study showed that subjects who adopted a vegan diet had their homocysteine levels drop between 13% and 20% in just ONE WEEK. [Preventive Medicine 2000;30:225-233.]

Recent research has found that statin drugs -- which reduce the blood level of cholesterol from animal foods -- appear to significantly lower the risk (by 73%) of Alzheimer's and dementia risk. [Archives of Neurology 2000;57:1439-1443]

In another report, researchers observed the dietary habits of nearly 8,000 men and women free of dementia upon enrolling in the study. When re-examined six years later, those who ate foods rich in vitamins E and C (plant foods) were less likely to have developed Alzheimer's disease. [Mulnard RA, Cotman CW, Kawas C, et al. Estrogen replacement therapy for treatment of mild to moderate Alzheimer's disease: a randomized controlled trial. Alzheimer's Disease Cooperative Study. JAMA 2000;283:1007-15.]

The clear message if you're concerned about Alzheimer's? Lose the meat and dairy, eat fruits and veggies.

Marker for Heart Disease, Too

Several large, well designed studies have shown a clear association between homocysteine levels and heart attack and stroke. Not only does meat and dairy consumption raise cholesterol, it raises homocysteine, which is now widely seen as a separate risk marker for heart disease.

Vitamins and supplements are not as effective as diet in lowering homocysteine levels. This led the American Heart Association last year to make the following statement: "Fresh fruits and vegetables, rather than vitamin supplements, are the best line of defense against raised homocysteine levels, an indicator of heart disease."

Help Prevent Heart Disease, Cancer -- and Alzheimers -- via Diet

We'll wait to see if any further research materializes to back up the one curious study purporting to show a relationship between Alzheimers and soy consumption.

In the meantime, the available scientific data are already plentiful to show that you can reduce your risk of being an Alzheimer's victim the same way you can lower your risk of certain cancers and heart disease -- by eating a healthy plant-based diet, rich in fresh fruits and vegetables, whole grains and legumes.

See related study: Veg Diet Gives Protection Against Alzheimer's