Question:
Here's an interesting snippet I've just come across. Anyone have any viewson it? It seems that meat eaters are more likely to become demented thanvegetarians - I must say it's the first coverage of this issue I've ever seen.If anything, one might have expected rather the reverse, what with all oursoya/aluminium consumption...

The incidence of dementia and intake of animal products: preliminaryfindings from the Adventist Health Study. Giem P; Beeson WL; Fraser GE Neuroepidemiology 1993, 12 (1) p28-36

We investigated the relationship between animal product consumption andevidence of dementia in two cohort substudies. The first enrolled 272California residents matched for age, sex, and zip code (1 vegan, 1lacto-ovo-vegetarian, and 2 'heavy' meat eaters in each of 68 quartets).This design ensured a wide range of dietary exposure. The second included2,984 unmatched subjects who resided within the Loma Linda, Californiaarea. All subjects were enrolled in the Adventist Health Study. The matchedsubjects who ate meat (including poultry and fish) were more than twice aslikely to become demented as their vegetarian counterparts (relative risk2.18, p = 0.065) and the discrepancy was further widened (relative risk2.99, p = 0.048) when past meat consumption was taken into account.

Answer: Senile dementia is a major problem in the U.S. I've covered this area inSci.Med. in the past and got hit pretty hard when I suggested that thefirst line of treatment for senile dementia should be diet and not drugs orshock treatment.

There are a number of nutrients in the vegetarian diet that could play arole in senile dementia. Folic acid is deficient in the typical Americandiet (about 50% of the RDA). This problem (which causes spinal tube birthdefects) is a hot area of debate right now (should the U.S. food supply befortified with folic acid?).

I had a Geriatric manual that covered senile dementia and recommended folicacid supplementation before any other kind of treatment but I gave it toone of our physicians who specializes in geriatrics. I have one paperwhich links a folate deficiency to dementia ("Reversible dementia andneuropathy associated with folate deficiency 16 years after partialgastrectomy", Scand J Haematol 25:63,1980).

The only good source of folate from animal foods is liver. Muscle willhave some tetrahydrofolate (the active form of folate) but in comparison tothe folate content in plants (especially leafy vegetables, remember myspinach recipe?) animal foods pale in comparison.

But plant folate is not active. It exists as a pentaglutamate derivativewhich has to be hydrolyzed in the gut using a B12 requiring peptidase.Animal folate is better absorbed and utilized than plant folate but thedifference in content more than makes up for the difference inbioavailability (as long as your B12 status is good).