The phytosterols in certain plant foods may have important effects on cholesterol absorption and metabolism, suggests a recent study.
Researchers from Washington University in St Louis, US tested whether the concentration of phytosterols in low-fat vegetable foods are high enough to reduce cholesterol absorption and favourably affect lipid metabolism.
They found that efficiency of cholesterol absorption from test meals was substantially lower after consumption of wheat germ than after consumption of a control wheat germ which had phytosterols extracted from it.
Wheat germ was chosen as the test food as it has a high content of phytosterols relative to total fat. The researchers measured cholesterol absorption in 10 subjects after eating muffins containing 30 mg heptadeuterated cholesterol tracer and, in random order, 80g original wheat germ containing 328mg phytosterols, wheat germ from which phytosterols had been selectively extracted, or extracted wheat germ reconstituted with purified phytosterols.
Changes in cholesterol absorption were measured 4 and 5 days after each meal. Tracer enrichment of plasma cholesterol was 42.8 per cent higher after consumption of phytosterol-free wheat germ than after that of the original wheat germ, report the researchers in this month's American Journal of Clinical Nutrition. Tracer enrichment of plasma cholesterol was not significantly different between the wheat germ with extracted-and-reconstituted phytosterol and the original wheat germ, they added.
The small study suggests that natural phytosterols in wheat germ and possibly in other low-fat vegetable foods may help reduce elevated cholesterol levels.