When the Hong Kong Consumer Council (HKCC) tested 27 types of ready-to-eat laver (dried seaweed) on the market, the results showed that all samples had high iodine content. Excessive iodine consumption may affect thyroid function.
The tests also found that 70 percent of the laver samples were “high in sodium,” and nearly 40 percent were “high in fat.” The Council worried that people who consumed multiple servings of laver at one time could increase the risk of excessive sodium and fat intake.
Two to five metal pollutants were detected and the carcinogens cadmium and inorganic arsenic were found in all samples. (Provided by The Consumer Council)
The types of laver tested included 18 types for snacks, eight for sushi or rice balls, and one type of shredded laver. The price per 100 grams (3.53 ounces) of laver ranges from $5.17 to $49.26. The most expensive laver for sushi or rice balls comes from Korea.
The HKCC testing found that all the samples belonged to the food “rich in iodine” under the Food and Drugs (Composition and Labelling) Regulations. The iodine content ranged from 34.6 milligrams (0,53 grain) to 1,030 milligrams (15.9 grains) of iodine per 100 grams (3.53 ounces). The HKCC recommends manufacturers declare the iodine content on the nutrition labels of products for consumers’ reference.
The HKCC pointed out that iodine is an essential mineral for maintaining human metabolism and moderate consumption of seaweed can prevent insufficient iodine intake, but long-term excessive intake of iodine will affect thyroid function, and can cause both hypothyroidism and hyperthyroidism.
The Consumer Council said, for example, a sample of “Topvalu” containing 20 pieces of laver with the highest iodine content, contains 34.6 milligrams (0.53 grains) of iodine per 100 grams (3.53 ounces), and 2 pieces (1.5 to 2.6 grams) will provide 900 milligrams of iodine, which is 50 percent of the upper limit recommended by the WHO.
Metal Contaminants
The Council also tested the levels of metal contaminants in the laver, including cadmium, lead, chromium, total mercury, inorganic arsenic, and antimony, and found that 27 types of samples were found to contain two to five types of metal pollutants, and all samples were found to have carcinogenic cadmium and inorganic arsenic. No antimony was detected in the samples. However, the content of the metal contaminants did not exceed the upper limits set by Hong Kong, the European Union, and the international community, normal consumption of which will not affect health.High Sodium and High Fat Levels
The testing also found that 19 types of laver had “high sodium” levels, ranging from 614 milligrams (9.6 grains) to 4.8 grams (0.17 ounces) of sodium per 100 grams (3.53 ounces). There were 10 samples of laver that showed “high-fat” content, containing 29.1 to 60.4 grams (1.03 to 2.13 ounces) of fat per 100 grams (3.53 ounces). Among them, the brand with the highest fat content was Little Boss Crispy Seaweed Spicy Flavor, which had the highest content of total fat, saturated fatty acids, and trans fatty acids per 100 grams (3.53 ounces) among the samples. Nine types of laver snacks had both “high sodium” and “high fat” levels.According to the Hong Kong Dietitians Association (HKDA), laver without additional seasoning is low in calories and contains nutrients such as dietary fiber, vitamins, and minerals. Laver is also a source of various phytochemicals, including sulfated polysaccharides (with anti-inflammatory properties that may help protect cardiovascular health) and fucoxanthin (with antioxidant properties that may help improve blood sugar control and reduce the risk of type II diabetes). According to the American Chemical Society’s 2011 Journal of Agricultural and Food Chemistry, bioactive peptides contained in laver may help lower blood pressure and cholesterol, promote heart health, and prevent certain cancers.
