Re: Tofu: Bad News

Harvey Newstrom (
Sat, 27 Nov 1999 13:55:57 -0500

Ian Goddard <> wrote to <> on Saturday, November 27, 1999 4:24 am:
> Too much tofu induces 'brain aging,' study shows
> A Hawaii research team says high consumption
> of the soy product by a group of men lowered
> mental abilities
> By Helen Altonn
> Star-Bulletin

I have been watching this recent research with some concern, because I am a vegetarian and eat tofu. However, we have to be careful when a single new study comes out that refutes previous studies. Most studies show soy foods helping fight cancer and aging. Maybe tofu does lower mental acuity, but helps in other ways.

The study did not indicate higher death rates or disease rates among those who ate tofu. They seemed to score lower on mental acuity tests, which are much more subjective. Such test scores vary between cultural groups and economic class. It may simply be that more Americanized Japanese eat less tofu and have better English language skills than less Americanized Japanese who eat more tofu and have lessor English language skills. The differences may actually be in English-speaking acuity.

I am concerned that the study asked men about "27 foods and drinks" in their diet. That is not very many items. There is no way that they got a good picture of their overall dietary habits from just 27 questions. They claim to have eliminated all other dietary factors except tofu, but I don't see 27 foods and drinks as being a complete dietary accounting. I also would have preferred a nutrient workup rather than a food list. I would want to know which nutrients were deficient and which were abundant.

I am also concerned about how much difference was really detected. They said that those who ate "a lot of tofu" by the time they were "75-80 years old" scored on tests as if they were five years older. A few years variance at that age isn't very much difference. Those who ate less tofu than "a lot" will see less of an effect, even if it exists.

I would like to see more study in this area. In the meantime, I will continue to eat some tofu, but not a lot of tofu. I still see a lot more evidence for the benefits of soy than harmful effects. It probably will turn out, that like everything else, soy is good in moderation, but too much can be harmful.

Harvey Newstrom <mailto://>
Author, Consultant, Engineer, Legal Hacker, Researcher, Scientist.