Recently the researchers found that an extract of Fucus vesiculosus, which is a type of seaweed, promotes the contraction of fibroblast-populated collagen gels through increased expression of integrin molecules. In this study, they investigated the effects of topical application of an aqueous extract of this alga on the thickness and the mechanical properties of human skin. A gel formulation that included 1% of the extract was applied topically to human cheek skin twice daily for five weeks. A significant decrease in skin thickness measured by B-mode ultrasound was elicited, as was a significant improvement in elasticity measured with a Cutometer as compared with controls. In cheek skin, the thickness normally increases and the elasticity usually decreases with age.
– J Cosmet Sci 2002 Jan-Feb;53(1):1-9 — Treatment of human skin with an extract of Fucus vesiculosus changes its thickness and mechanical properties. — Fujimura T, Tsukahara K, Moriwaki S, Kitahara T, Sano T, Takema Y.
Iodine concentration, on the other hand, could be of concern with regard to human health. Regular consumption of algae, especially of Laminaria sp., could result in levels of iodine sufficient to cause thyroid problems.
– Environ Res 1999 Feb;80(2 Pt 2):S175-S182 — Evaluation of the contamination of marine algae (Seaweed) from the St. Lawrence River and likely to be consumed by humans.– Phaneuf D, Cote I, Dumas P, Ferron LA, LeBlanc A.
Possibility of presence of toxic heavy metals.
– Fucus vesiculosus: a nephrotoxic alga? — Conz PA, et al. — Nephrol Dial Transplant. 1998 Feb;13(2):526-7.
A number of seaweed-based products were analysed for total and ‘reducible’ arsenic and total iodine. Maximum potential intakes of the two elements were estimated using the manufacturers’ recommended does. The levels of reducible arsenic found were generally low and, with one exception, ingestion of the products is unlikely to lead to the Joint Expert Committee on Food Additives (JECFA) Tolerable Daily Intake being exceeded. Iodine levels varied widely even between different samples of the same product. In a number of these cases the potential iodine intake is very high.
– Food Addit Contam 1988 Jan-Mar;5(1):103-9 — Human intake of arsenic and iodine from seaweed-based food supplements and health foods available in the UK. — Norman JA, Pickford CJ, Sanders TW, Waller M. — Ministry of Agriculture, Fisheries and Food, Food Science Division, London, UK.