Seaweed (kelps) and plasma glucose and insulin levels

I have been using Kelps (Ascophyllum nodosum and Fucus vesiculosus) for patients since 1997 where I was observing student clinic while studying naturopathy and nutrition at College. As part of observing in student clinic, we were able to suggest treatments, diets, herbs, vitamins, minerals, amino acids, etc., to the “practitioner student” who would then formulate the treatment of the patient. The kelps have numerous health benefits. I have typically used Kelps for hair, skin, and nails, and for thyroid health (all due to the iodine content) throughout my career.

A randomised placebo-controlled crossover trial investigated the effect of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) on post-challenge plasma glucose and insulin levels in men and women. Two 250 mg seaweed capsules and 2 placebo capsules were consumed on each occasion 30 minutes prior to the consumption of 50 g of carbohydrates from bread. Plasma glucose and insulin concentrations were measured over a period of 3 hours post-carbohydrate ingestion at predetermined time points. Both treatments were separated by a 1-week washout period. Data were analysed using mixed models for repeated measures. Compared with placebo, consumption of seaweed was associated with a 12.1% reduction in the insulin incremental area under the curve (p = 0.04, adjusted for baseline) and a 7.9% increase in the Cederholm index of insulin sensitivity (p < 0.05). Consumption of the seaweed capsules was not associated with any adverse event.

Kelps may have benefit in people with insulin resistance.

Fucoidan: An interesting constituent of kelps is Fucoidan. Fucoidan is a type of polysaccharide which contains substantial percentages of L-fucose and sulfate ester groups, mainly derived from brown seaweed. The polysaccharide was named as “fucoidin” when it was first isolated from marine brown algae by Kylin in 1913. Fucoidans have been extensively studied due to their numerous activities, including antioxidant, anti-inflammatory, anticoagulant, anti-thrombotic, immunomodulatory, antiviral, blood lipid reducing, and gastric protective effects.


Bo L et al. Fucoidan: structure and bioactivity. Molecules. 2008 Aug 12; 13(8): 1671-95.

Paradis ME et al. A randomised crossover placebo-controlled trial investigating the effect of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) on postchallenge plasma glucose and insulin levels in men and women. Appl Physiol Nutr Metab. 2011 Dec; 36(6): 913-9.