Phytosterols, which are natural compounds found in plants, especially nuts and oil seeds, have a structure similar to that of cholesterol, and therefore compete with it in the intestine, limiting its absorption. Phytostanols are produced through the hydrogenation of phytosterols.
European regulations authorise the labelling of phytosterol- and phytostanol-fortified products with a claim that these substances lower blood cholesterol and that lowering blood cholesterol can reduce the risk of coronary heart disease.
In order to address certain concerns, the consumer association UFC-Que Choisir decided to request that ANSES assess the risks and benefits of consuming food products fortified with phytosterols and phytostanols.
What products are fortified with phytosterols? Who eats them?
An analysis of the French market shows that phytosterol fortification is currently found mainly in three types of products – margarines, fresh dairy and related products, and condiment sauces –, accounting for about 4% of their respective market shares.
According to the INCA 2 study of individual and national food consumption in France carried out by ANSES, consumers of these products in 2006-2007 accounted for about 3% of adults and 0.7% of children. Among adults, the 46-79 age range, which may be considered most at risk of high cholesterol, was the most heavily represented. Children made up 12.5% of phytosterol-fortified food consumers.
Phytosterol consumption: a lack of data on the risks and benefits
While phytosterols do indeed contribute to a mean reduction of about 10% of total blood cholesterol levels and of circulating LDL cholesterol (commonly known as “bad cholesterol”), there is considerable individual variability in response to phytosterols. In about 30% of subjects, the consumption of foods fortified with phytosterols leads to no reduction in LDL cholesterol.
The consumption of foods fortified with phytosterols also leads to an increase in plasma concentrations of phytosterols, for which the consequences on cardiovascular risk are unknown.
Furthermore, a reduction in plasma concentrations of β-carotene is also observed following consumption of phytosterols, which is likely to increase cardiovascular risk.
Lastly, there are no studies concerning the direct effects of phytosterols on cardiovascular events that would make it possible to take a position on the results of the effects of phytosterols on all these intermediate parameters (LDL cholesterol, plasma phytosterols, plasma β-carotene). At present, it is therefore not possible to reach a conclusion on the effects of phytosterols for the prevention of cardiovascular risk.
Phytosterols are not an appropriate means of preventing cardiovascular disease at the population level
Faced with these scientific uncertainties, ANSES considers that, in view of the data currently available, it is not possible to conclude that foods fortified with phytosterols are a suitable means of prevention of cardiovascular diseases in the population as a whole.
While blood LDL cholesterol is considered to be a risk factor for cardiovascular disease, ANSES reiterates that these diseases are multifactorial, involving a large number of both risk factors and protective factors. As a result, reducing a single risk factor does not necessarily reduce the risk of disease.
The Agency also reiterates that there are several recognised health and dietary measures that act as levers for prevention, such as stopping smoking, increasing physical activity, reducing sedentary behaviour and improving dietary balance by ensuring sufficient consumption of fruits and vegetables, a balanced intake of fatty acids and moderate consumption of sugar and salt. At individual level, it is doctors’ responsibility to adapt the different available measures to their patients suffering from high cholesterol.
ANSES therefore recommends that:
- people concerned about their cholesterol levels should consult a health professional who will be able to recommend the most suitable health and dietary measures for their particular situation;
- consumers of products fortified with phytosterols should make sure that they consume, at the very least, the quantities of fruits and vegetables recommended by the French National Health and Nutrition Programme (PNNS), in order to compensate for the reduction in β-carotene caused by consuming these products;
- children should avoid consumingproducts fortified with phytosterols;
- pregnant and breastfeeding women should avoid consuming products fortified with phytosterols.