A green algae supplement has been shown to boost the immune system's response to the flu vaccine in people aged 50-55 years old. While not consistent across other age groups, the findings demonstrate the potential role of food supplements alongside pharmaceuticals.
The pill tested in the study, a carbohydrate extract of green algae called Respondin, is manufactured by Canadian marine ingredients firm Ocean Nutrition.
"Our clinical study clearly demonstrates Respondin has a biological effect in humans, increasing the antibody response to a flu vaccine in this population," said Dr Scott Halperin, a professor of paediatrics and associate professor of microbiology and immunology at Dalhousie University in Canada.
"These results have raised the bar, showing that natural products can be studied for clinical effect in a pharmaceutical-calibre study. The true clinical role for Respondin needs to be determined through future study," he added.
The team, which included researchers from Ocean Nutrition, gave two different doses of the extract, a patented carbohydrate fraction from the green microalgae Chlorella pyrenoidosa, to two groups of 41 healthy adults for 28 days. Another 42 subjects received a placebo. All subjects were at least 50 years of age. After 21 days of supplementation all subjects received a vaccine designed for the 2000/2001 flu season, which contained three different flu strains.
Subjects aged 50-55 years receiving the 400 milligram/day dose showed significantly greater antibody responses to the vaccine seven and 21 days after vaccination, reported the team in the Canadian Medical Association Journal. However the supplement did not increase antibody response to the flu vaccine overall. There were no adverse effects from taking the Respondin.
Further studies are needed to clarify the actual clinical benefits of the supplement. Ocean Nutrition said it has other studies planned or underway to explore other potential uses such as helping to alleviate allergy symptoms or helping the body's immune system battle infections.