A new study indicates that the consumption of soy protein does not help preserve cognitive abilities in females aged 45+, contrary to earlier reports and beliefs, researchers from Stanford University in Palo Alto, Calif, reported in Neurology. The authors added that soy protein might help women’s memory for facial recognition.
Study author Victor W. Henderson, MD, MS, said:
“Soy is a staple of many traditional Asian diets and has been thought possibly to improve cognition in postmenopausal women. Our study found long-term use of soy protein neither improved nor impaired overall cognition.”
In this randomized human study, Henderson and team gave 313 healthy females 25 grams of soy protein or a milk protein-matched placebo each day, they were aged from 45 to 92 years. The soy protein dose is said to be equivalent to what is found in Asian diets.
The women also underwent tests that gauged their memory and cognitive (thinking) abilities at the beginning of the study, and then two-and-a-half years later.
The authors wrote that there was no significant difference between the cognitive and memory scores of the women in the soy and milk protein groups.
However, visual memory, what the researchers refer to as facial recognition, improved slightly more in the soy group compared to the milk one (13% difference).
Henderson said:
“Our study provides strong evidence that soy supplements should not be used by postmenopausal women with the main goal of enhancing overall cognitive ability. On the other hand, a diet high in soy protein does not appear to have any harmful effect on thinking skills, either.”
Written by Christian Nordqvist