When women experience the menopause, their natural oestrogen levels decline gradually over two to ten years, but the side effects of oestrogen replacement therapy (ERT) may include increased risk of breast cancer and cardiovascular disease, and vaginal bleeding.

Given these drawbacks, interest has been piqued in the effects of dietary phytoestrogens like soy isoflavones that have a weak oestrogen-like action, which may provide the same benefits as ERT, without the risks.

And the new randomised, double-blind, cross-over clinical trial, published in the journal Fertility and Sterility (Vol. 85, pp. 972-978), indicates that isoflavones from soy may improve cognitive function and mood of post-menopausal women.

The presence of oestrogen receptors in the central nervous system indicates its role in cognitive function. To test the effect of phytoestrogens from soy, the researchers divided 76 post-menopausal women (average age 49.5 with 5.7 years of menopause) to receive either a daily 600 mg tablet with 60 mg of isoflavones (40-45 per cent daidzein, 40-45 per cent genistein, 10-20 per cent glycitein in the aglycone form) or an identical looking placebo.

After six months of supplements, the subjects underwent a month-long washout period before crossing over to the other intervention group for a further six month.

Psychological evaluation was done using the Diagnostic and Statistical Manual of Mental Disorders (DSM) fourth edition. A battery of tests were performed to measure cognitive function and mood, including depression.

The researchers found that women taking the isoflavone supplements had significantly improved scores on six on the 17 scales used, while the placebo produced no improvements.

“These data strongly suggest that the phytoestrogens may ameliorate the quality of life for most post-menopausal patients, in terms of mood and cognitive function,” said the researchers.

“The widespread presence of oestrogen receptors in the regions of the brain involved in the regulation of [cognitive] functions, together with the cognition of the multiple enzymatic activity of oestrogen affecting the related metabolic pathways, seems to strongly support that these hormones should have a key role both in cognitive functioning and mood,” said Casini.

Consumer interest in mental health and the products that benefit this are on the increase. To some extent, the ‘baby boom' generation (people born between 1946 and 1964) explain the increased interest in supplements for mental health and cognitive function, especially given fears over the rising incidence of Alzheimer's and other age-related diseases.

Data drawn from Mintel's Global New Products Database indicates that the category has caught marketers' attention most markedly from the early 2000s onwards.

Overall, the database shows up more product launches in the category in the US over the past 10 years than in Europe: 255 product lines (product variants not included) to 139.

As one would expect given the amount of science and media attention in the last few years, omega-3 (DHA and EPA, and, to a lesser extent, ALA), figure large in Mintel's results.

But certain other ingredients also crop up time and again. These include gingko biloba and ginseng (linked to improved memory); soy lecithin; CoQ10 (reported to help slow the progression of Parkinson's disease); and St John's wort (recognised as combating depression).
Data source: Mintel's Global New Products Database