Health Benefits of Sea Vegetables
Sea vegetables, also known as edible seaweeds, are not only incredibly tasty, they’re also one of the most unique and nutritious foods on the planet! They’ve been consumed for thousands of years in coastal areas like Japan (where seaweed residue has been found in clay pots dating back to 3000 BC!), and in one of Japan’s earliest legal codes (the Taiho Code of in the 8th century AD), were even legislated to be an acceptable form of tax payment.
Seaweeds have some special components that aren’t found in any land-based vegetables, and which may be responsible for some of their unique health benefits:
- Fucoxanthin, a type of carotenoid that gives seaweeds a brown pigment, and which has potent anti-cancer properties, the ability to reduce liver fat and liver enzymes, and the potential to boost metabolic rate and assist in fat loss!
- Astaxanthin, another carotenoid that’s been linked to improved skin health, cardiovascular health, joint health, and reduced cancer risk.
- Fucoidans and laminarins, sulfated polysaccharides that have been shown to induce cell death of certain cancers (such as lymphoma), have antiviral and neuroprotective properties, help slow blood clotting, improve osteoarthritis via anti-inflammatory effects, and may help modulate the immune system (although in most of these cases, more research in humans is needed to know for sure).
- Alginates, cell-wall constituents of brown algae that may help in weight loss, glycemic control, and appetite regulation.
Numerous studies have shown that some components in seaweed help fight inflammation! The fucoxanthin in seaweed is the biggie here: it can inhibit nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) protein expressions, and also suppress the production of a variety of inflammatory cytokines (like IL-1β, TNF-α, and IL-6). That might sound like a lot of complicated science, but basically, it just means that the carotenoid in seaweed can tank pro-inflammatory mediators and help reduce excessive inflammation in the body. (Of course, that has a risk-lowering effect for the numerous conditions that stem from chronic inflammation, too!)
Among seaweed’s many perks is the potential to cardiovascular health! The antioxidant and anti-inflammatory properties of fucoxanthin can help thwart multiple processes involved in the progression of heart disease, while also modulating immune function. And, research has shown that a many seaweeds have hypolipidemic (lipid-lowering) activity, helping reduce levels of triglycerides and LDL cholesterol. And, the DHA found in algae and algal oil can not only reduce triglycerides and LDL cholesterol, but also raise HDL cholesterol—which, collectively, paint a more favorable picture for combating heart disease!
In Traditional Chinese Medicine and Japanese folk medicine, seaweeds have long been used to treat tumors, and Western science is beginning to discover why! Multiple studies have shown that seaweed can increase apoptosis (programmed death) of tumor cells, prevent the growth of new blood vessels that supply tumors, inhibit tumor cell adhesion, and prevent metastasis. Whew! That’s a pretty impressive lineup, huh? And, even small amounts of seaweed seem to have a big effect. In one study of postmenopausal women, consuming just 5 grams of brown seaweed each day resulted in a 50% drop in a type of receptor that’s over-expressed in cancer (urokinase-type plasminogen activator receptor, or uPAR, which is involved in multiple signaling pathways, cell adhesion, inflammation, immune function activation, tissue repair, and a number of other functions). The key players behind seaweed’s anti-cancer effects may be its fucoxanthin content, its polyphenolic compounds, its sulfated polysaccharides (fucoidan and laminarin), its ability to increase the colon’s protective mucus bilayer, and its ability to bind dietary toxins and carcinogens by increasing stool bulk.
And, sea vegetables may be particularly beneficial for lowering the risk of estrogen-related cancers. In a small but fascinating case study of three menopausal women, intake of brown kelp was associated with a significant increase in menstrual cycle length and lower estrogen and higher progesterone levels—all factors that would result in lower estrogen exposure over the course of life, potentially helping protect against certain cancers in women who are estrogen-sensitive. In fact, the traditional use of seaweed in some parts of Asia (like Japan) may help explain why those areas have much lower rates of certain cancers (especially breast cancer) than most Westernized nations!
Another incredible feature of seaweed is its antiviral potential. The sulfated polysaccharides in seaweed can block the interaction between many viruses and host cells—including important pathogens like HIV, herpes simplex, dengue virus, respiratory syncytial virus, and human cytomegalovirus. And, seaweed appears to contain other antiviral components that are enhanced by light (especially UVA) and not only protect our cells, but can directly inactivate the virus particles themselves.
Examples of Sea Vegetables
- sea grape
- sea kale
- sea lettuce
Nutrients in Sea Vegetables
Expand to see all scientific references for this article.
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