In a study published in the journal Nutrition Research, researchers from The Catholic University of Korea isolated a compound from wakame called fucoidan and examined its anti-diabetic activity. Fucoidan is a carbohydrate that has been found to reduce blood glucose levels in mice. Upon testing its effects on normal and insulin-resistant fat cells, the researchers found that fucoidan can improve insulin sensitivity and prevent basal lipolysis (breakdown of fat cells) -- a process that occurs excessively during obesity and is closely associated with insulin resistance.
Fucoidan is a sulfated polysaccharide -- an important component of cell walls -- that can be found in many species of algae. Sulfated polysaccharides possess biological activities that are beneficial to human health. Some of these include antioxidant, anti-viral, anti-tumor, antibacterial and anti-inflammatory activities. According to animal studies, fucoidan has the ability to improve learning and memory impairment, inhibit liver fibrosis (excessive scarring) and stop the proliferation of breast cancer cells.
In their study, the Korean researchers hypothesized that the pharmacological properties of fucoidan may allow it to act directly on adipocytes (fat cells) and exert anti-diabetic effects. To test this hypothesis, they isolated fucoidan from wakame and treated adipocytes with 10, 50, 100 and 200 micrograms per milliliter (mcg/mL) of fucoidan. Then, they assessed lipid accumulation during adipocyte differentiation.
The researchers reported that fucoidan reduced lipid accumulation and glycerol-3-phosphate dehydrogenase (GDPH) activity -- both of which are dysregulated in diabetes -- in a dose-dependent manner. Fucoidan also suppressed the expression of peroxisome proliferator-activated receptor y (PPAR-y), a major transcription factor associated with adipocyte differentiation. PPAR-y is the target of Type 2-diabetes drugs like thiazolidinediones which are used to increase insulin sensitivity.
Fucoidan treatment also stimulated glucose uptake in normal adipocytes and restored insulin-stimulated glucose uptake in adipocytes with obesity-induced insulin resistance. In the presence of RAW 264.7 macrophages, fucoidan enhanced epinephrine-stimulated lipolysis but reduced basal lipolysis.
Based on these results, the researchers concluded that fucoidan exerts its anti-diabetic effects by improving insulin-stimulated glucose uptake and inhibiting basal lipolysis in adipocytes without inducing adipogenesis (formation of new adipocytes).
Wakame is a slightly sweet, silky sea vegetable that's commonly used to make salads or added to miso soup. It is a great source of essential nutrients, such as vitamins A, C, E, K and B9 (folate), and minerals like sodium, magnesium, manganese and calcium. Wakame is also rich in iodine, a mineral required for the production of thyroid hormones. Iodine deficiency is a common health problem and is the main cause of hypothyroidism. (Related: Wakame: an iodine-rich seaweed with impressive fat burning properties.)
Besides micronutrients, wakame also contains plenty of anti-inflammatory and antioxidant compounds. A study published in the Journal of Applied Phycology even linked the lower incidence and mortality rates of post-menopausal breast cancer in Japan to the consumption of wakame. Researchers found that eating wakame helps decrease the concentration of a protein known as uPAR, which plays a major role in tumor progression and metastasis. uPAR is elevated among post-menopausal women in general.
Although wakame is low in fat, it is also a great source of omega-3 fatty acids. In fact, wakame contains the highest amount of omega-3 fatty acids among all vegetarian sources. Omega-3 fatty acids are not only good for the heart, they also help with mental health problems like depression and ADHD, as well as hormonal issues.
Enjoy the health benefits of wakame by adding it to your daily diet. To avoid any adverse effects, eat only moderate amounts and avoid wakame products that contain a lot of sodium.