Avoid isoflavones on menus in mass catering
The isoflavones naturally found in certain plants can have harmful effects on health, particularly on the reproductive system, if consumed in excessive amounts. As soy is the main source of isoflavones, ANSES is recommending that soy-based foods not be served in mass catering establishments to avoid over-consumption. It is also calling on the agri-food sector to review soy production and processing techniques, in order to reduce isoflavone levels in foods.
Soy is the main source of isoflavones
At the request of the Directorate General for Food (DGAL) and the Directorate General for Health (DGS), ANSES assessed the health risks of consuming foods containing isoflavones and the possibility of serving them in mass catering establishments. Isoflavones are a class of compounds known to have oestrogenic hormonal activity. They are naturally found in pulses (also known as legumes) and vegetables, but levels are particularly high in certain foods made from soy: the foods containing the most isoflavones are all soy-based. The work carried out by ANSES therefore led to the recommendation not to serve soy-based foods in mass catering, regardless of the age group.
Risks of toxic effects on the reproductive system
To reach this conclusion, ANSES first defined oral health-based guidance values (HBGVs), i.e. thresholds below which there is virtually no health risk. To do this, it drew on the scientific knowledge available in humans and animals. Two HBGVs were established on the basis of toxic effects on the reproductive system: one for the general population, of 0.02 mg/kg body weight/day, and another for pregnant women, women of childbearing age and prepubertal children, of 0.01 mg/kg body weight/day.
These values were then compared with the dietary exposure levels of the French population calculated from data collected in the INCA3, TDS2 and iTDS studies conducted by ANSES.
It concluded that there is a risk that consumers of soy-based foods could exceed the HBGVs: 76% of children from 3 to 5 years of age consuming these foods exceed the HBGV, as do 53% of girls aged 11 to 17. 47% of men aged 18 and over and women aged 18 to 50. These results led ANSES to recommend that these foods not be offered in mass catering establishments, to prevent meals taken in these settings from contributing to the risk of exceeding the HBGVs.
Reducing isoflavone levels in soy is necessary and possible
The Agency recommends diversifying plant-based foods in the diet, bearing in mind that pulses other than soy contain far fewer isoflavones. Action can also be taken to reduce isoflavone levels in soy-based products. At present, these levels vary widely. For example, there are 100 times more isoflavones in soy-based cocktail biscuits than in soy sauce. This variability can also be found within the same food, for example, levels among soy desserts on the French market can vary by a factor of two. This is due to a number of reasons: firstly, the variety of soy, the growing conditions and the degree of maturity of the plant, and secondly, the manufacturing processes or recipe formulation. ANSES therefore recommends that companies and producers implement agronomic techniques and manufacturing processes that produce foods with controlled isoflavone levels.