ANSES, the Food Safety Agency, has just published its opinion on the maximum cadmium content for algae intended for food, which is increasingly present on plates. It is indeed important to set a threshold in order to prevent their consumption from leading to over-exposure of the population to this suspected carcinogenic substance.

Nori, wakame, dulce ... The consumption of edible seaweed is an emerging phenomenon in France. Eaten as vegetables or processed (dried, salted, fresh, in jars, etc.), certain species of algae are also used in food supplements. In a context where algae-based products are increasingly offered to consumers, ANSES, the Food Safety Agency, has assessed the risk of excess cadmium intake because currently, the European Union regulations do not set a direct maximum level for the latter. However, since consumers are already exposed to cadmium on a daily basis, the Agency recommends setting a maximum concentration.

"Rich in polysaccharides, algae tend to load up with trace metal elements, such as cadmium, lead and arsenic. The 250 analyzes of samples concerning unprocessed algae show concentrations of cadmium exceeding, for 26% of them, the maximum value of 0.5 mg / kg of dry weight recommended by the Higher Council of Public Hygiene of France (CHSPF) ”, indicates ANSES. Cadmium is a contaminant widespread in the environment in its natural state and due to human activity, particularly in agriculture and industry. It enters plants through their roots and thus enters the food chain.

A propensity to bind contaminants present in the environment

Another source of exposure is inhalation of tobacco smoke. Cadmium is known to be carcinogenic, mutagenic and toxic for reproduction because it can cause kidney damage and bone fragility in humans during prolonged exposure, especially by the oral route through food and drinking water. Given that "part of the French population is already exposed to it beyond the tolerable dose through their usual diet", ANSES therefore recommends a maximum concentration "as low as possible" in edible algae. What would this content be? 0.35 milligrams per kilogram of dry matter in the latter.

In its opinion accompanying its information point, the Agency stresses that "this content ensures, in 95% of cases, that the tolerable daily intake of cadmium is not exceeded. "In addition," since algae strongly contribute to dietary exposure to cadmium for those who consume them, such a content would lower the contribution of algae to the tolerable daily intake of cadmium to 11.5%, whereas it is currently at 19% in the observations and that it would be 15.5% if the algae consumed respected the CSHPF value of 0.5 mg / kg of dry matter ”, she adds. Still, experts are faced with weak data on consumption habits in France.

A greater or lesser risk depending on the type of algae consumed

A gap that does not allow more precise recommendations to be established depending on the type of algae and consumption patterns. This is why the Agency recommends carrying out a new survey to collect more figures in this area, in order to make recommendations on the maximum quantity of algae or level of cadmium concentration not to be exceeded, depending on the type of 'algae: microalgae, red, green or brown macroalgae, etc. However, analyzes have already made it possible to establish that cadmium contaminations are more important for brown (wakame often eaten in salads) and red algae (nori in leaf form or as an ingredient in makis, for example).

“Finally, the expertise highlights the risk of higher overexposure to chemical contaminants by combining the consumption of seaweed with other foods. This is particularly the case for inorganic arsenic when the consumption of Hijiki Hizikia fusiform seaweed is combined with that of rice. », Concludes ANSES. Note that this is not the first opinion of the Agency on this subject since in 2018 its experts mentioned a risk "of not insignificantly exceeding the upper limits of safe iodine intake. »It turns out that an excessive and regular intake of iodine can lead to dysfunction of the thyroid but also of undesirable effects at the cardiac or renal level.