|Among the challenges faced by people seeking valid nutritional information is that commercial media thrive on drama and controversy. Accurate, nondramatic information about healthy foods won’t sell as many copies or garner as many website hits as hard-hitting yet misleading headlines claiming miracle cures or life-threatening toxic reactions. And while these patterns are by no means unique to media coverage of soy foods, two recent examples of misleading stories about soy provide excellent cases in point.
Tofu Causes Dementia?
I awoke one morning earlier this year to find headlines on numerous health websites about a study on elderly Indonesians. A team of British researchers found that those who ate tofu daily had weaker memory function than those who ate it rarely. This led to alarming headlines circling the world (for example, “Eating Soy Linked to Memory Loss” and “Tofu May Raise Risk of Dementia“) which generalized these findings to all tofu, and implicitly or explicitly, to all soy products. As someone who has eaten soy products for many years, my interest was piqued. I decided to explore the story in greater depth.
First, the researchers who found that Indonesian elders eating two or more servings of tofu daily had worse memories (by about 20%) also found that eating tempeh (another Indonesian soy product) improved memory. This was strong evidence that soybeans were not themselves the source of the memory loss. Instead, something about tofu, or perhaps something specific about the tofu eaten in Indonesia, appeared to be the issue.
Was there anything about Indonesian tofu that might be a problem? In fact, it turns out that formaldehyde is used in Indonesia as a preservative for tofu. Formaldehyde is a known neurotoxin. It damages brain cells.
Most Stories Miss the Main Point
Was this information noted in the scores of articles that circled the globe? In most, it was left out completely, while in a few it appeared only several paragraphs down into the text. Interestingly, the best article among the dozens I reviewed appeared in the Jakarta Post, the largest newspaper in the capital of Indonesia. This isn’t all that surprising because readers, reporters and editors in Jakarta were the ones whose friends and relatives stood to be most directly and personally impacted by the story.
So what did the Jakarta Post story include that all others left out? Read on.
The study’s lead author, Professor Eef Hogervorst of the University of Loughborough, said tofu’s associations with a worsening memory might be attributed to formaldehyde contents in the soy product.
“The culprit may be formaldehyde but we need further study to confirm this.”
Formaldehyde had killed brain cells of rats in a study, she said.
Further nutrients that can reduce the risk of dementia include vitamin B12 and anti-oxidants, but Hogervorst said these were more effective if consumed as part of the diet and not as tablets.
Active people with a higher education were less likely to develop dementia, while smokers and drinkers were in a high risk category, she said.
“Besides those factors, diseases or illnesses like diabetes mellitus, high blood pressure, high LDL-cholesterol, obesity and cardiovascular disease are among things negatively affecting the brain,” she said.
Thus, the real bottom line is that tofu consumed in Indonesia, in which formaldehyde is present, is associated with memory loss in the elderly. The lead scientist says further studies are needed to clarify this possible chain of causation. Soy products such as tempeh do not harm memory, and in fact appear to improve it.