A study has shown that a combined supplement containing omega-3, vitamin E and niacin offer antioxidant could offer protection against heart disease.
The individual compounds have all been reported to protect against cardiovascular disease (CVD), a disease that causes almost 50 per cent of deaths in Europe, and is reported to cost the EU economy an estimated €169bn ($202bn) per year.
"Combining different compounds, which protect each other and act together at different levels of lipid chain production, improves lipid profile, inflammatory and oxidative status, allowing us to reduce the dose of each compound under the threshold of its side effects," reported lead author Roberto Accinni in the journal Nutrition, Metabolism and Cardiovascular Diseases (Vol. 16, pp. 121-127).
The randomised, blinded clinical trial divided 57 volunteers (average age 48, average BMI 27 kg/m2) into three groups: The first group (control - group A) received a placebo, the second group (group B) received a supplement containing omega-3 fatty acids (660 mg EPA, 440 mg DHA) and vitamin E (4 mg alpha-tocopherol), and the third group (group C) received that same as B plus niacin (18 mg) and gamma-oryzanol (40.2 mg).
People with diagnosed CVD, diabetes, high blood pressure, or taking lipid lowering medication were excluded from the trial.
After four months of supplementation the researchers took several biochemical measurements to determine the efficacy of the supplements.
The total antioxidant capacity (TAC), measured from blood samples, had increased significantly during the four months - group B's TAC increased by 33.55 micromoles per millilitre (mm/ml), and groups C's by 84 mm/ml. The placebo group's TAC measure decreased by 16.15 mm/ml.
Blood levels of vitamin E were found to be significantly higher in group C, but not in group B - a result attributed to the presence of both niacin and gamma-oryzanol, which preserve vitamin E status.
Concentrations of pro-inflammatory cytokines, interleukin 1-beta (IL 1-beta) and tumour necrosis factor alpha (TNF-alpha), also decreased as a result of the supplementation. The decrease in IL 1-beta, however, was only significant for group C.
"Judging by our results, four months' supplementation produced a beneficial effect on dyslipidemia, oxidative equilibrium and inflammatory status in patients treated with omega-3 fatty acids, vitamins and gamma-oryzanol," said the researchers from Italy's Institute of Clinical Physiology.
The authors said that a number of complementing mechanisms, most still unknown, were behind the activity observed by this combination supplement. Omega-3 fatty acids, for example, have been proposed to lower pro-inflammatory cytokines by the uptake and incorporation of EHA into the cell membranes.
Both niacin and gamma-oryzanol appeared to enhance the antioxidant power of the supplement, and spared vitamin E levels in the blood.
Interestingly, the researchers pointed out that unlike other reports, the use of niacin produced benefits and no side-effects, "thanks to small doses."
Side effects of too much niacin include abdonimal cramps, vomiting and ulcers, for example, and these are reported to occur at doses above 1000 milligrams per day (mg/day). The RDA for niacin is only 15 mg/day for women and 19 mg/day for men in the US, 18 mg/day for adults in the EU. Supplements in the US are available with doses in the range 100 to 1000 mg. Most European supplements are in the range 50 to 100 mg.
The authors said that "it is not necessary to quantify exactly how much each component contribute to the improvement," stating instead that others have already reported on this.
However, this does not seem to agree with their claim that most of the complementing mechanisms were still unknown. It is clear that further research is needed to elucidate the synergetic activities of the such multi-compound supplements.
Multivitamins continue to outsell single vitamin supplements in the UK, according to Mintel, with £87m compared to £49m in 2004. The multivitamins also made up the largest part of the entire UK dietary supplements market in 2004, with 24 per cent. Omega-3-containing cod liver oil accounted for 20 per cent of the market in terms of sales.