Phytoestrogen content of common foodstuffs (micrograms of phytoestrogen per 100 grams)

Worried about eating too much “gender-bending” soya? It turns out a host of other foods also contain high levels of oestrogen-like chemicals, including beer, wine and roasted peanuts.

Gunter Kuhnle of the MRC Dunn Human Nutrition Unit in Cambridge, UK, and colleagues surveyed dozens of foods and beverages using mass spectrometry, an extremely sensitive chemical technique. Most previous surveys of foods and drinks focused on one kind of phytoestrogen that is found in high levels in nuts and seeds called lignans, but ignored another kind called isoflavones.

By searching for isoflavones, Kuhnle found that phytoestrogens are present in far more foods and drinks than had previously been realised.

Studies on the health effects of phytoestrogens have painted a mixed and muddled picture. Some have hinted that the compounds protect against cancer, heart disease and the side-effects of the menopause, while others have linked high levels to an increased risk of breast cancer and male infertility. Still others have documented no link between phytoestrogens and those same ailments. So snack at your own risk – or reward.

Journal reference: Journal of Agricultural and Food Chemistry (DOI: 10.1021/jf801534g)