Serve Up Seaweed for Your Health, Blood Pressure

You may want to consider a side of seaweed with your next meal. A new review study finds that some seaweed proteins work just like the bioactive peptides in dairy foods, offering healthy nutrients and the ability to reduce blood pressure.
Seaweed is a highly nutritious food

According to Maria Hayes and her team, from Teagasc Food Research Centre in Ireland and the University of London, “bioactive peptides are defined as food-derived peptides that exert a physiological hormone-like effect in humans beyond their basic, nutritional value.” Some of the peptides act similarly to ACE inhibitors (e.g., enalapril, lisinopril), drugs prescribed to lower blood pressure.

Hayes and the team reviewed nearly 100 scientific studies and reported that these peptides, which are currently derived from milk-based products, are also available in seaweeds. Also referred to as macroalgae, edible seaweeds “produce unique and interesting biologically active compounds,” noted the authors, because of the harsh and unique environment in which they live.

Macroalgae offer a variety of macronutrients and micronutrients. A recent report in Food Science and Technology International, for example, noted the dietary fiber, mineral content, fatty acid and amino acid profiles, antioxidant activity, and polyphenolic concentration of three edible Spanish seaweeds, two brown (Himanthalia elongate and Undaria pinnatifida) and one red (Porphyra umbilicalis).

In the brown seaweeds, fiber and ash were the most common components, and in the red, protein and fiber dominated. All three seaweeds had all the essential amino acids at adequate levels and contained high levels of polyunsaturated fatty acids. Brown seaweeds revealed a rich source of potassium, calcium, sodium, and magnesium.

Along with their high nutritional value, edible seaweeds are low in calories and in fat. They can be processed and added to food products for those who shy away from the thought of eating seaweeds, and they are easy to cultivate.

Edible seaweeds are enjoyed by many peoples around the world, especially those living in coastal regions. People in China, Korea, and Japan have used seaweeds extensively since prehistoric times, and the macroalgae are also eaten in Wales, Ireland, Iceland, France, Norway, New Zealand, and eastern parts of Canada.

Hayes and her team note that the next step is to determine the impact of processing methods, including heating, on the nutrients in seaweed. Although experts have shown that peptides can keep their bioactivity after reaching temperatures of 212 degrees Fahrenheit, many processes reach higher temperatures. If higher temperatures threaten the potency of the peptides, ways to protect them, “such as microencapsulation methods, need to be investigated,” noted the authors.