A study commissioned by the company suggests vegetarians are unlikely to gain a sufficient level of omega-3s from a non-fish diet. Omega-3 fatty acids as well as fish consumption have been linked to reduced risk of heart disease.
But people that eat no fish rely on vegetable sources of omega-3 fatty acids, such as plants rich in alpha-linolenic acid (ALA). ALA is converted by the body to DHA but this makes it a less efficient source of the key omega-3 fats and means that vegetarians could be missing out on the fatty acids thought to protect the heart.
Nevertheless, producers of algae-derived DHA or fish oils are under pressure from makers of flaxseed oil or other vegetable oils rich in ALA, who offer a cheaper product. And a recent Mintel survey suggests that most companies launching products said to be rich in omega-3 are using vegetable sources to make these claims, rather than the DHA-rich options.
The new study investigated how Nutrinova's DHA from microalgae could boost the omega-3 index of vegetarians.
The omega-3 index indicates the blood level of the omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA. A low omega-3 index has recently been described as an indicator for increased risk of coronary heart disease.
For the double-blind, randomized, intervention study, the researchers gave 104 healthy vegetarians a DHA supplement (0.94 g DHA) or an olive oil placebo for eight weeks.
Although most of the participants reached recommended intakes foressential fatty acids, such as alpha-linolenic acid (ALA), none ofthem reached a recommended omega-3 index of at least 8 per cent, shows the study reported in the August issue of Lipids (vol 40, issue 8, pp807-14).
At the end of the study, the omega-3 index increased significantly in the supplement group, with 69 per cent of these subjects reaching an omega-3 index above 8 per cent.
None of those in the placebo group attained this level.
"This suggests that the in vivo conversion of ALA (as available from plant sources such as flax) to EPA and DHA is not adequate to reach a desirable EPA and DHA status," said Nutrinova in a statement.
There was also a significant increase in the EPA level after DHA supplementation, suggesting that the firm's DHA is also suitable for enhancing levels of both fatty acids.
"We conclude that an 8-wk supplementation with 0.94g DHA per day from microalgae oil achieves a beneficial omega-3 index of at least 8 per cent in most subjects with low basal EPA + DHA status," write the researchers.