Heart Healthy Additives

article image
courtesy Agricultural Research Service/Keith Weller
Margarine-based products marketed to lower cholesterol.

Plant-derived
sterols and stanols are known to be heart healthy compounds. When consumed in
amounts greater than those found naturally in foods, these compounds lower
blood cholesterol concentrations in humans. To help consumers gain this
benefit, food companies add sterols and stanols to foods.

Now, authors of
a U.S. Department of Agriculture (USDA)-supported study have found that blood
plasma low-density lipoprotein (LDL or “bad” cholesterol) is lowered
most when plant sterols are consumed in smaller amounts more often throughout
the day, rather than in one large amount each day.

Numerous
clinical trials have shown that consuming foods enriched with at least 0.8
grams and up to 3 grams of plant sterols or stanols daily lowers LDL cholesterol.
Margarine spreads or orange juice enriched with the compounds, for example,
often are consumed once daily as part of breakfast.

Researcher Alice
Lichtenstein and her colleagues studied the effect on blood cholesterol levels
of giving volunteers plant sterols once in the morning, compared with giving
sterols three times a day. Lichtenstein is director of the Cardiovascular
Nutrition Laboratory at the Jean Mayer USDA Human Nutrition
Research Center
on Aging at Tufts University in Boston,
Mass. The research was partially
funded by the Agricultural Research Service, USDA’s principal intramural
scientific research agency. 

Lichtenstein
analyzed lipid (blood fat) profiles of 19 study volunteers from blood samples
taken after each of three 6-day study phases-a relatively short intervention
period.

For the control
phase, the volunteers were given a precisely controlled weight-maintaining
diet, with no plant sterols. For the second phase, the volunteers were given
the same diet, but with a standardized amount of 1.8 grams of plant sterols in
margarine with breakfast. For the third phase, the volunteers were given the
same diet, but also 1.8 grams of plant sterols divided equally and given during
each of the three meals per day.

Volunteers
consumed their regular, habitual diets for two weeks between each phase of the
study.

Among the group
that received the plant sterols three times per day, measures of LDL
cholesterol decreased by 6 percent, and this decrease was attributed to a
substantial reduction in cholesterol absorption compared with the control phase
of the study. The 2009 study was published in the European Journal of Clinical Nutrition.