Professor says that long-term consumption of plant sterol-enriched margarines may increase cardiovascular risk

This study was published in the British Medical Journal Case Reports 2009;2009. pii: bcr10.2008.1108

Study title and authors:
Extravascular lipid deposit (xanthelasma) induced by a plant sterol-enriched margarine.

Vergès B, Athias A, Petit JM, Brindisi MC.
Hôpital du Bocage, 2 Bd Maréchal de Lattre de Tassigny, Dijon 21000, France.

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/21822448

A 59 year old woman consumed a plant sterol-enriched margarine of 20 g/day (Fruit d’Or Pro-activ margarine, containing 8% phytosterols), corresponding to 1.6 g/day phytosterols.

(i) After 18 months of regular consumption of plant sterol-enriched margarine, the woman developed xanthelasma. (Xanthelasma are fatty lumps, which tend to form near the inner corners of the upper and lower eyelids).
(ii) The woman's phytosterol levels were significantly increased (165 μmol/l); (normal is less than 25 μmol/l).
(iii) The woman discontinued her consumption of plant sterol-enriched margarine. Three months later, her phytosterol levels were normal (20 μmol/l).

Professor Bruno Verges, who headed this investigation, concluded: "The increase in plasma phytosterol concentrations due to plant sterol-enriched margarines could be harmful, and we cannot exclude that long-term consumption of plant sterol-enriched margarines may increase cardiovascular risk".

Comparison of levels of phytosterols in vegetables, fruit and plant sterol-enriched margarines

The average phytosterol content of vegetables is 14 mg per 100 grams. Vegetables with the highest content include brussels sprouts at 43 mg per 100 grams and cauliflower at 40 mg per 100 grams.

The average phytosterol content of fruits is 16 mg per 100 grams. Fruits with the highest content include passion fruit at 44 mg per 100 grams and oranges at 24 mg per 100 grams. See here.

The phytosterol content of plant sterol-enriched margarine is much higher:
Take Control Spread 11,784 mg per 100 grams.
Fruit d’Or Pro-activ margarine 8,000 mg per 100 grams. (Fruit d'Or is also sold as Flora and Becel).
Benecol 6,070 mg per 100 grams.

The presence of phytosterols in very small quantities in fruit and vegetables suggests that they may be beneficial to health in very small quantities. However the phytosterol content of plant sterol-enriched margarines are higher by an order of magnitude of up to 841 times than the average vegetable.

This abnormally large increase in phytosterol consumption highlights the potential risk of toxicity that may be caused by excess phytosterols in plant sterol-enriched margarines.