Children who consume more isoflavones from soy foods show better thinking skills and attention

A new study found that school-age children who consumed more isoflavones from soy foods exhibited better thinking skills and attention. These findings pave the way for future research aimed at discovering how soy foods can positively affect children’s cognitive abilities.

Isoflavones are natural compounds found in various plants, especially soybeans and soy products. Although previous research in adults has suggested that soy isoflavones may improve memory, the benefits have not been well studied in children.

Soy foods are often not a regular part of children’s diets in the United States. Our study adds to the evidence for the importance of nutrients found in soy foods for childhood cognition.”

Ajla Bristina, PhD student in neuroscience, University of Illinois Urbana-Champaign

Bristina will present the findings at NUTRITION 2024, the main annual meeting of the American Society for Nutrition held June 29 through July 2 in Chicago.

To examine the potential benefits of soy isoflavones, researchers examined previously available data from a cross-sectional study involving 128 children aged 7 to 13 years. They used information from the 7-day dietary records to calculate each child’s average dietary intake, including the amounts of macronutrients, micronutrients, vitamins and isoflavones consumed. To assess the children’s general intellectual ability, the researchers used a battery of pencil-and-paper tests adjusted for grade level. They also measured attentional skills using a computerized task known as the flanker task while electroencephalographic (EEG) activity was recorded and used to measure information processing speed and attention.

“No other study has examined the relationship between soy isoflavones and attention skills using EEG or similar measures to record the electrical activity generated by the brain,” Bristina said.

Overall, the analysis found that the children in the study tended to consume low amounts of isoflavone-containing soy foods. However, those who consumed more soy foods showed faster responses during attention tasks and exhibited faster processing speed. No association was observed between soy isoflavone intake and general intellectual ability.

“The children in our study consumed an average of 1.33 mg of isoflavones per day, which, while relatively low, is consistent with previously reported values ​​for the United States,” Bristina said. “Soy intake for individual participants ranged from 0 to 35 mg/day. To put this in perspective, an 8 fl. oz. serving of soy milk provides about 28 mg of isoflavones, a serving of tofu provides about 35 mg, and half a cup. Edamame steamed provides about 18 mg of isoflavones.”

Bristina says foods like roasted edamame, soynuts or soy milk are a good way to include more soy in the diet. Tofu, tempeh, or soy-based nuggets are also good meal options.

“Correlational studies like this are just the first step,” Bristina said. “To better understand the effects of eating soy foods on children’s cognitive abilities and the exact amount of isoflavone intake needed to elicit faster reaction times, intervention approaches will be required.” To find out more, the research team recently started a clinical trial examining the effects of soy foods on thinking skills, sex hormones, metabolic health and gut health.

Bristina will present this research at 8:12-8:24 a.m. CDT on Tuesday, July 2, during the Nutritional Neuroscience: Nutritional Effects on Cognition and Disease Severity across the Lifespan session at McCormick Place (abstract; presentation details).

Please note that abstracts presented at NUTRITION 2024 were evaluated and selected by an expert committee, but generally have not undergone the same peer review process required for publication in a scientific journal. As such, the findings presented should be considered preliminary until a peer-reviewed publication is available.