Laminaria digitata is the scientific name of the brown seaweed also known as Sea Kelp or Wonder Kelp. It grows at the Atlantic coast of the southern Brittany1 and the last years has attracted the interest of many researchers who study it extensively for its’ medicinal and biological properties. Scientists believe that this ancient sea plant is a source of elements that no longer exist in the plants that are grown in the soil and that its’ chemical composition is very similar to that of the human plasma2 . The Sea Kelp contains a qualitative and quantitative composition of biologically active substances like amino acids, polyunsaturated fatty acids, antioxidants, alginate, vitamins (A, C, D, B1, B2, B3, B6, B12, E, K, PP), macro- and micro-nutrients (K, Na, Ca, Mg, I, S, Si, etc.), which make it a highly effective supplement to ensure the normal functioning of the body and treat several diseases.
The history of Sea Kelp use
Based on archaeological evidence from 14,000 yBP in Chile3 and early written scripts (for example in China, 300 A.D. and in Ireland, 600 A.D. 4-9 ) humans have been using algae for thousands of years, not only for food but also for their medicinal properties. Nowadays, Laminaria species are mostly harvested in Scotland, Ireland, Norway, France, China, Japan and Korea. They are a very popular food in Asian countries and a very expensive raw material in Japan and Korea3 for the extraction of alginates, binding agents that absorb toxic heavy metals and radioactive isotopes from the body by binding with them in the gastrointestinal tract. Many scientific studies have shown that the consumption of Sea Kelp has antibacterial and anti-inflammatory or even antitumor properties1,9. For instance, fucoidan a polysaccharide present in several Laminaria species has been shown to have antivirus, antibacterial, antioxidant and anticancer properties 2 .
Sea Kelp and iodine
Furthermore, the high content of Sea Kelp in iodine 10-12 , especially of Laminaria and Saccharina species, links this seaweed with a long history of its consumption by humans and the reduced incidence of goiter and other thyroid disorders. Iodine is essential for thyroid hormone synthesis and its deficiency causes hypothyroidism while excess iodine uptake can induce either hyper- or hypothyroidism 12 . Iodine intake is also critical during pregnancy. It has been shown that many iodine deficiency disorders (IDD) may occur to the fetus due to the impaired synthesis of thyroid hormones in both the mother and the fetus. Such abnormalities include abortions, stillbirths, congenital anomalies, increased perinatal mortality, endemic cretinism, impaired mental function, retarded physical development or goiter complicat ions 13-15 .
Why iodine is important for your health?
Insufficient iodine uptake is not only a problem in developing countries, but is also characterized as a major public health problem in many countries in Europe and the Western world 16-19 . According to a recent study in UK 20 that analysed mother–child pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort by measuring urinary iodine concentration in stored samples from 1040 first-trimester pregnant women, iodine deficiency in pregnant women in the UK should be treated as an important public health issue that needs attention. Finally, according to Lazarus (2014 )21 a significant part of the population in Europe is mildly deficient in iodine and an increase in dietary iodine consumption by 50-100 μg/day would be beneficial.
Which form of iodine is the best supplement?
Given the risks of potential iodine-induced thyroid dysfunctions, the American Thyroid Association also recommends the ingestion of an iodine or kelp daily supplement containing >500 μg iodine for all individuals, except for certain medical indications22 . However, there are several iodine supplements available in the market. Which kind of supplement is better? Potassium iodine tablets or Sea kelp tablets? This is actually not only a question of tablet quality and purity, but also of iodine bioavailability (i.e. how much iodine is actually assimilated in the body). In average, 100 g of the dry kelp contains 0.13–0.69 g iodine2 when the recommended daily nutrient intake of iodine is 90 μg (RNIa) for the age group 0–59months, 120 μg for the age group 6–12 years, 150 μg for adolescents and adults and 250 μg during pregnancy and lactation, respectively23, 24 . According to scientific studies the bioavailability of natural seaweeds is lower comparing to potassium iodine tablets25 , as the content of iodine in the seaweed varies according to the season that was harvested and as the iodine is not in a pure form as in the tablets. Furthermore, many people support that iodine should be taken mostly by our diet. However, Sea Kelp contains not only large amounts of various micro- and macronutrients, but also many vitamins which correspond to a huge variety of fruits and vegetables and make it a wonderful supplement for preventing or treating numerous diseases2 . By using Sea Kelp tablets, we do not only supplement our diet with iodine, but also with calcium helping our bones, antioxidant and anti-inflammatory substances, polyunsaturated fatty acids that normalize blood pressure, cholesterol , and blood sugar rates and many vitamins increasing our body resistibility to any physical and psychoemotional stress.
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Recommended nutrient intake (RNI) refers to the daily intake which meets the nutrient requirements of almost all (97.5%) apparently healthy individuals in an age- and sex-specific population group. It is set at the estimated average requirement plus 2 standard deviations.
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