Study pinpoints actions of heart health ingredients

Researchers at the University of São Paulo in Brazil scrutinized 159 studies and evaluated the effects of three bioactive substances - omega-3 fatty acids, soluble fibers and phytosterols - on plasma total cholesterol, triacylglycerol, LDL cholesterol, and HDL cholesterol.

They established that phytosterols and soluble fibers have a hypocholesterolemic effect. Omega-3 fatty acids, on the other hand, were seen to lower triacyglycerol but increase total, LDL and HDL cholesterol.

These findings are published in The American Journal of Clinical Nutrition​ (vol. 82, no. 1, 32-40).

The researchers undertook the review of clinical studies on the ability of functional foods ingredients to lower the risk of heart disease because it judged the results of many of them to be contradictory.

Their conclusions could have a bearing on the formulation of functional foods, a relatively new but rapidly growing sector of the food industry in which heart health is a major driving force.

A report published by Leatherhead Food​ in April set the current value of the functional food heart health market at $3.6 billion. It predicted that the number of heart health products on the market will increase by as much as 60 percent in the next five years.

According to the American Heart Association, 34.2 percent of Americans (70.1 million people) suffered from some form of cardiovascular disease (CVD) in 2002. CVD was the cause of 0.9 million deaths.

More than 50 percent of American adults had total cholesterol of 200 mg/dL or higher in 2002, and in 18.3 percent it was above 240ml/dL.

In moderate cases, health care professionals do now tend to recommend a dietary approach to controlling cholesterol over prescription drugs such as statins, which may have serious side effects.

Leatherhead said that, at present, cereals make up 46 percent of the foods carrying heart health claims in the US, Japan, Australia and five major European markets due to their high fiber content and the repositioning of major brands to highlight the benefits of wholegrains.

Phytosterols and phytostanols are being included in a number of new cholesterol-lowering foods, and other sectors, such as diary, are seeing a good deal of product development.

The popularity of heart health ingredients is linked to the amount of scientific evidence supporting their claims, with the most used being omega-3 fatty acids, phytosterols, fibre, vitamins C and E, folic acid and potassium. Bioactive peptides have also been shown to tackle high blood pressure.

But Leatherhead said that other ingredients, such as carotenoids, B vitamins, garlic, polyphenols and magnesium, are also likely to be used more often, especially if they are subjected to more scientific research.

More research is definitely needed into the heart health actions of conjugated linoleic acid, plant lignans, rice bran oil, co-enzyme Q10 and betaine, said the report.

In their review, the Brazilian researchers used a multivariate statistical approach known as principal component analysis (PCA) and a mixed model to process data. They said that their methodology was important, as it showed that the substances' effects were independent of dose, number of patients per study and body mass index. However they were associated with the length of the study.

Nonetheless, they concluded that PCA is useful for summarizing scientific information on health claims for food and supplements.