The lack of knowledge regarding the value of iodine and of possible iodine sources in food has often led to cases of proven deficiency. Notably, iodine found in cow milk cannot be found in land-plant alternatives. Strict vegan diets have led to severe iodine deficiencies. These background cases are an opportunity to better enhance and formulate with algae.
Algae: a source of iodine to adjust diets with low amounts of animal-based ingredients.
In the UK, cow milk is the main source of iodine in the diet. This is not the case for cow milk alternatives such as soya, almond, coconut, rice, oat, hazelnut and hemp milks or juices.
The iodine content in alternatives to cow milk has been studied and shows a global average of 7.3 µg iodine/ kg, all alternatives combined. As a matter of comparison, conventional cow milk contains an average of 438 µg / kg of iodine, while certified organic milk has a lower average content of 324 µg / kg. The high iodine levels in cow milk can be explained by agricultural practices: supply of concentrates rich in iodine to livestock and use of iodine disinfectants before milking.
Alternatives to cow milk are often supplemented with calcium, but milk supplemented with iodine is scarce. However, iodine deficiency is present in certain groups of people in the United Kingdom, in particular among pregnant women. As a reminder, the iodine requirement for pregnant women is higher and established at 250 µg iodine / day. These identified deficiencies are of particular concern because iodine is essential for the brain development of the foetus.
A recent German study has confirmed the risk of iodine deficiency for people who do not consume animal-based products, and this by comparing the nutritional status of vegans compared to omnivores. No difference was shown between both groups regarding the iron, vitamin B12 or vitamin D levels, and this was due to dietary supplements used by most vegan people. Indeed, even if the animal-based products were totally excluded from a diet, which resulted in almost no vitamin B12 supply, supplementation enabled to reach a totally satisfactory nutritional status in vitamin B12.
On the other hand, concern was given to the iodine level which showed a low iodine urine level for ¾ of the omnivore population and almost the whole vegan population. Moreover, about 1/3rd of the vegans even had an iodine urine content below the WHO threshold defined for severe deficiencies.
Although the risks of lacking certain well identified nutrients, which are specifically associated to animal products such as iron, vitamin B12 or vitamin D, are well looked at and diets adjusted in consequence with specific measures and supplements, the risk of iodine deficiency on the other hand is neither known nor controlled.
When the algae biomass is carefully processed and prepared, it can be an asset for supplementing iodine naturally in everyday food products. The market is large with a growing number of consumers turning towards flexitarian, vegetarian or vegan diets. Authors reported approximately 6 million vegetarian consumers and almost a million following a strict vegan diet in Germany alone.
Therefore, in the view on this present context, high levels of iodine in edible algae would be a real asset to exploit. Indeed, the adult recommended daily intake (RDI) for iodine, which is 150 µg / day, can be reached by consuming only very small amounts of algae, such as a few grams of unprepared dried seaweed. Consuming 7 g of dried Palmaria palmata covers an average of 67% of the iodine RDI, whilst 0.7 g of dried Saccharina latissima covers more than 2400% of the RDI. However, existing culinary techniques, such as blanching or just soaking of the biomass, can significantly reduce the iodine content which seems to be easy to wash out when present in excessive levels.
It is therefore important to vary the species of algae, to adapt the preparation methods and to regulate one’s consumption to prevent the risk of exceeding recommended thresholds.
This is an opportunity and a path worth innovating for edible algae. We can help you optimise and formulate acceptable and balanced products. Feel free to contact us…
References
Sarah C. Bath, Sarah Hill, Heidi Goenaga Infante, Sarah Elghul, Carolina J. Nezianya, and Margaret P. Rayman. Iodine concentration of milk-alternative drinks available in the UK in comparison to cows’ milk. Br J Nutr. 2017 October ; 118(7): 525–532. doi:10.1017/S0007114517002136.
Cornelia Weikert, Iris Trefflich, Juliane Menzel, Rima Obeid, Alessa Longree, Jutta Dierkes,
Klaus Meyer, Isabelle Herter-Aeberli, Knut Mai, Gabriele I. Stangl, Sandra M. Müller, Tanja Schwerdtle, Alfonso Lampen, Klaus Abraham. Vitamin and Mineral Status in a Vegan Diet. Deutsches Ärzteblatt International | Dtsch Arztebl Int 2020; 117: 575–82
