Soy May Help Some Men Remember Anniversaries
Lee Swanson Research Update
A small study from Australia shows that daily supplementation with soy isoflavones could help boost a man’s mental function and memory.
Men receiving daily supplements of the isoflavones performed significantly better in tests of their working memory, report scientists from the University of South Australia and the University of Adelaide in the British Journal of Nutrition.
The beneficial effects may be related to the estrogenic effects of the isoflavones, researchers said, noting that the improvements were in cognitive processes, “which appear dependent on estrogen activation.”
Researchers, led by Peter Howe, recruited 34 healthy men to participate in their 12-week double-blind, placebo-controlled cross-over trial. The men were randomly assigned to receive a daily dose of 116 mg of soy isoflavones, providing 68 mg of daidzein, 12 mg of genistein and 36 mg of glycitein, or placebo for six weeks. They were subsequently crossed-over to the other intervention for the following six weeks.
Tests of memory, mental function and visual-spatial processing performed before and after the supplementation period showed that the isoflavone supplements were associated with improved spatial working memory; “a test in which females consistently perform better than males,” the researchers said.
Indeed, men receiving the isoflavones required 18% fewer attempts to correctly complete the tasks, committed 23% fewer errors and achieved the tasks in 17% less time than they did during the placebo phase.
However, the researchers note that the soy had no apparent effect on either auditory or episodic memory, executive function, or visual-spatial processing.
“Isoflavone supplementation in healthy males may enhance cognitive processes that appear dependent on estrogen activation,” they stated.
Commenting on the possible mechanism of action, Howe and his co-workers noted that it has already been reported that females “perform better in certain memory-related tasks than males.” This has been attributed to differences in circulating estrogen levels. The female hormone interacts with certain receptors in the hippocampus, frontal lobe and cortex of the brain that play a role in mental function.
British Journal of Nutrition, Published online before print.