The fashion is for Japanese catering, for “sushi” and the seaweed that often accompanies them. In addition, the rise of seaweed-based food supplements prompted ANSES to take stock of the potential risks associated with the iodine content of seaweed.
Until not so long ago, and this is still the case for part of the population, achieving sufficient iodine intake was not easy. Especially for those who do not consume seafood products. But with the iodine enrichment of salt, breads… and the strong growth in the consumption of seaweed, including in the form of food supplements, we can ask about the risk of excessive iodine intake. This is what the National Health Security Agency (ANSES) did, with the conclusion that vigilance is required.
Proven risks of iodine excess
First clarification from the agency following its investigations: the iodine content of seaweed-based products varies according to the production conditions, the transformation process and the type of preparation. The algae richest in iodine are the brown kelp algae and the red algae Gracilaria verrucous.
Secondly, the Agency considers that the consumption of seaweed presents a risk of exceeding the upper safety limits (600 µg/day for adults according to the EFSA), especially when seaweed consumption is combined (particularly under formed dried) and food supplement based on seaweed. The consequences to be feared are thyroid dysfunction as well as adverse cardiac or renal effects.
Who should pay attention first?
ANSES therefore advises against the consumption of foods and food supplements containing algae for those most vulnerable to excess iodine. It’s about:
people with thyroid dysfunction, heart disease, or kidney failure; pregnant or breastfeeding women, without medical advice.
It also makes various recommendations, to the attention of:
– parents: remain cautious about the consumption of seaweed-based products by their children;
– health professionals: declare the adverse effects likely to be linked to the consumption of food supplements.
It should also be noted that in Japan, where the consumption of seaweed is high, the seaweed is generally treated to greatly reduce its iodine content.