Emergence of Seaweed and Seaweed-Containing Foods in the UK: Focus on Labeling, Iodine Content, Toxicity and Nutrition

Abstract

Seaweed (edible algae) is not a staple food in the Western diet, despite occasional use as a traditional ingredient in coastal areas. High nutritional value, combined with the expansion of the health-food industry, has led to a resurgence of seaweed in the British diet. While seaweed could be useful in tackling dietary iodine insufficiency, consumption of some species and sources of seaweed has also been associated with risks, such as toxicity from high iodine levels, or accumulation of arsenic, heavy metals and contaminants. The current retail level of seaweed and edible algae in the UK market, either as whole foods or ingredients, was evaluated with particular focus on labelling and iodine content. Seaweed-containing products (n = 224) were identified. Only 22 products (10%) stated information regarding iodine content and another 40 (18%) provided information sufficient to estimate the iodine content. For these products, the median iodine content was 110 μg/g (IQR 21–503) and 585 μg per estimated serving (IQR 105–2520). While calculations for iodine exposure per serving relied on assumptions, 26 products could potentially lead to an iodine intake above the (European) tolerable adult upper level of 600 μg/day. In the context of the data presented, there is scope to improve product labelling (species, source, processing, content).

Food safety hazards in the European seaweed chain

“…Retails samples of kelp ( n = 20; species unknown) from the United Kingdom had a wide range of I concentrations from 25 to 1,200 mg/kg dw, with variations seen among different samples of the same product (Norman, Pickford, Sanders, & Waller, ). However, in a later study, Bouga and Combet () indicated that a limited amount of the sampled U.K. seaweed‐containing products (10%; n = 224) provided information on I. Given estimated calculations for I exposure per serving (ranging from 0.5 g to 350 g), 26 seaweed products could potentially lead to I above the EU UL of 0.6 mg/day (Bouga & Combet, ).…”

“…However, in a later study, Bouga and Combet () indicated that a limited amount of the sampled U.K. seaweed‐containing products (10%; n = 224) provided information on I. Given estimated calculations for I exposure per serving (ranging from 0.5 g to 350 g), 26 seaweed products could potentially lead to I above the EU UL of 0.6 mg/day (Bouga & Combet, ). The lack of information on seaweed type, source, and I content means that estimates on the safety and suitability of such products still need to be refined, also considering the population exposed.…”

Health Functionality and Quality Control of Laver (Porphyra, Pyropia): Current Issues and Future Perspectives as an Edible Seaweed

“…Major food constituents with side-effects are iodine, fibers, and sodium (in seasoned laver). Iodine has beneficial effects on thyroid gland functioning, but excessive intake should be avoided to prevent potential adverse effects such as autoimmune thyroiditis or hypothyroidism [94][95][96][97][98]. Overconsumption of fibers can lead to vomiting or abdominal pain with diarrhea in people with sensitive stomachs and may cause dyspepsia even in healthy people due to generation of gases in the digestive system [99].…”

Antimicrobial potential of macro and microalgae against pathogenic and spoilage microorganisms in food

“…The main limitations affecting the application of algae in food products are related to sensory (residual flavor and aroma) and toxicological aspects (high iodine levels, or accumulation of arsenic, heavy metals, and contaminants) (Bouga & Combet, 2015). These risks must be minimized in order to maximize the technological, functional, and nutritional advantages that are associated with macro-and microalgae materials and bioactive compounds.…”