Study links eating soy with better thinking ability

Could adding tofu to kids’ diets help them at school? A new study presented this week at the NUTRITION 2024 conference indicates the answer is yes.

Study authors found that “school-aged children who consumed more isoflavones from soy foods exhibited better thinking abilities and attention,” according to a press release from the American Society for Nutrition.

Soybeans are part of the legume family. They have been cultivated in Asia since the 11 ^th century B.C., according to the University of Nebraska-Lincoln , and the National Center for Complimentary and Integrative Health said they have been cultivated in other areas since the 1950s.

“Soy foods are often not a regular part of children’s diets in the United States,” said Ajla Bristina, a neuroscience doctoral student at the University of Illinois Urbana-Champaign who worked on the recent study. “Our study adds evidence of the importance of nutrients found in soy foods for childhood cognition.”

Bristina was slated to present the findings Tuesday morning at the NUTRITION conference, held at the McCormick Place convention center in Chicago, Ill.

According to the study press release, isoflavones naturally occur in various plants and are especially present in soy products. Previous studies have shown that these compounds can improve memory.

Tofu, or soybean curd, is a well-known soy product often used as a vegetarian or vegan meat replacement. It is made by curdling fresh, hot soymilk with coagulant, per UCSF Health .

Other sources of soy include edamame, beans harvested when they are green and sweet; miso, a paste often used in Japanese cuisine; soymilk, beans that are soaked and ground fine to produce a liquid; soy nuts, beans that are soaked and baked until brown; tempeh, a fermented product often mixed with grain and pressed into a cake; soy sauce and whole soybeans.

To study the potential benefits of soy isoflavones, Bristina and other researchers examined previously available data from a cross-sectional study that included 128 children ages 7 to 13.

“They used information from 7-day diet records to calculate each child’s average dietary intake, including the amounts of macronutrients, micronutrients, vitamins and isoflavones consumed,” said the press release. “To assess the children’s general intellectual ability, the researchers used a set of pencil and paper tests adjusted for grade level. They also measured attentional abilities using a computerized task known as the flanker task while electroencephalographic (EEG) activity was recorded and used to measure information processing speed and attention.”

Bristina said this is the first study to examine the association between soy isoflavones and attentional abilities using EEG or similar measures to record electrical activity generated by the brain. Findings indicate that children who consume more soy foods have faster responses during the attentional tasks and exhibit faster processing speed.

“No association was observed between soy isoflavone intake and general intellectual ability,” the press release noted. This research should be considered preliminary, as it has not yet been peer reviewed.

While soy has been lauded as a health food, other research has also revealed potential risks associated with it.

“Whether published in a popular press article or a well-designed clinical study, some debate about soy remains,” according to the Harvard T.H. Chan School of Public Health . It said that part of this uncertainty is “due to the intricacy of soy’s effects on the body,” and its isoflavone content in particular.

Isoflavones are a type of plant estrogen that functions similarly to human estrogen. These “isoflavones can bind to estrogen receptors in the body and cause either weak estrogenic or anti-estrogenic activity,” the school explained.

“Correlational studies like this are only the first step,” said Bristina of the research presented this week. “To better understand the effects of eating soy foods on children’s cognitive abilities and the precise amount of isoflavone intake necessary to elicit faster response times will require intervention approaches.”

Her team is now working on a clinical trial to examine the effects of soy foods on thinking abilities, sex hormones, metabolic health and gut health.