‘We are literally swimming in this vegetable and kelp farming is a new and potentially big industry on our very doorstep. Despite this, we know very little about how to use it as food.’
This was stated by Arne Duinker, scientist at the National Institute of Nutrition and Seafood Research (NIFES). NIFES is now starting up a project in which kelp’s potential as food will be investigated, as well as the risk associated with using kelp as an ingredient in our diets.
Kelp natural part of Asian diet
Asia has long traditions of using kelp as a natural ingredient in the diet, while Europe has not really started utilising this resource yet.
‘The background to the study is the worldwide hunt for new food resources and the desire to harvest more from the oceans. Asia has utilised an impressive variety of seafood for a long time and Europe is now starting to follow, but we have little knowledge about kelp. There are no regulations with maximum levels for the contaminants in kelp, and both producers and Food Safety Authorities in Europe are uncertain. That is why we are initiating this project to gain knowledge and set the basis for regulations,’ says NIFES scientist Bjørn Liaset.
A natural source of iodine
Kelp contains several nutrients that are lacking in the European diet, and it is particularly interesting that kelp contains high levels of iodine. People in Norway and large parts of Europe have too little iodine in their diet, and iodine is added to the feed of dairy cows and industrial salt in many countries to avoid deficiency diseases. Iodine deficiency can lead to low metabolism and is the most important cause of preventable brain damage in newborns.
This is where kelp comes in as a natural and very efficient source of iodine for the future. It is not without problems, however, since we should not consume too much iodine either. Just a small portion of kelp can lead to us exceeding the maximum limit of 600 micrograms of iodine per day.
‘Theoretically, just a few grams of fresh kelp may exceed the maximum limit for daily intake. Kelp cannot become a major food resource if we can only eat that little of it. At the same time, we know that kelp is an important element in the diets of many Asians, without this leading to any notable problems. Based on this, we will investigate how high doses of iodine affect us, and we need to see whether we tolerate more iodine from kelp than, for example, salt,’ says Liaset.
Will boil and fry kelp in the NIFES kitchen
NIFES scientists will put on their aprons and boil, fry and dry the kelp to examine the iodine content before and after. It is already known that some iodine disappears from kelp during processing and the scientists will now quantify how much of the iodine that remains in the kelp after the various processing methods. They will also examine how iodine from kelp is absorbed in the body and how this affects metabolism and health.
‘Previous studies show that there may be a slow release of iodine from kelp. Since kelp is slowly digested, the rate of iodine absorption may also be slow, and this may be more beneficial than for example fast absorption from salt,’ says Duinker.
‘We usually don’t eat kelp as meals every day. That is why we are going to use trials on rats to see whether we can tolerate more iodine from kelp if it is spread out over several portions,’ says Liaset.
Also contaminants in kelp
Another aspect of kelp that needs to be more closely examined is the content of contaminants. Compared with other seafood, kelp contains more of the heavy metals cadmium and inorganic arsenic and may also contain more copper. The project will measure the amount of different contaminants and whether they are absorbed and stored in the body.
‘There is some scepticism to introducing kelp because of potentially harmful contaminants, but contaminants are found in most foods we eat. For example, if we were now to start eating potatoes for the first time, we might be concerned that the potato could contain the toxin solanine. In practice, this is not a problem and we eat lots of potatoes. Kelp has an exciting potential as a more widely used ingredient in our diet, and we are therefore initiating research that can help to realise this potential,’ says Duinker.