Tuesday, 15 August, 2000, 23:49 GMT 00:49 UK
NEW YORK, Mar 22, 1999 (Reuters Health)Blue Green Algae May Lower Cholesterol
Studies in rats suggest that blue-green algae dietary supplements may help reduce levels of circulating cholesterol.
"We hypothesize that taking (an algae) supplement may help maintain cholesterol level within a healthy range," report Dr. Rafail Kushak and colleagues at Harvard Medical School in Boston, Massachusetts, and Dr. Christian Drapeau of Cell Tech in Klamath Falls, Oregon. Drapeau presented the findings at the national meeting of the American Chemical Society, held this week in Anaheim, California.
Numerous studies have suggested that high = dietary intake of polyunsaturated fatty acids (PUFAs) may help lower blood cholesterol levels and reduce risks for certain medical conditions including cardiovascular disease, arthritis, and mental illness.
The researchers point out that PUFAs comprise nearly = 10% of the dry weight of a blue-green algae known as Aphanizomenon flos-aquae, which grows naturally in North American lakes.
To help determine the algae's impact on cardiovascular health, the investigators fed laboratory rats either a standard diet supplemented with 5% soybean oil (another source of PUFAs), or a PUFA-deficient diet fortified with increasing amounts of dried blue green algae (up to 15%).
They report that the algae "is a better source of PUFA than soybean oil and has significant hypocholesterolemic (cholesterol-lowering) properties." According to Kushak and colleagues, rats fed diets supplemented "with 10% and 15% algae decreased (their blood) cholesterol level to 54% and 25%" of those of rats fed the standard diet.
The algae may also be a highly efficient source of alpha-linolenic acid (LNA), a compound that has been linked in earlier research to reduced risks for cancer and cardiovascular disease. While both soybean oil and blue-green algae contain LNA, the authors note that rats required triple the amount of soybean oil in their diets to achieve the same level of circulating LNA of rats fed algae.
According to the researchers, this finding suggests that the LNA in algae may be more efficiently absorbed into the digestive system than the LNA found in soybean oil.
Overall, the study results suggest that the benefits of algae supplementation exceed those of soybean oil, despite the fact that the oil contains amounts of PUFA equal or greater to that found in algae. "This suggests that the hypocholesterolemic effect of Aph. flos-aquae is likely to be (influenced) by factors other than its fatty acid content," the investigators conclude.
