Rye bread is more than just the basis for a great sandwich; it’s also rich in fiber, vitamins and minerals. Researchers at the University of Helsinki in Finland increased the heart-healthy profile of rye bread by enriching it with 2-4 grams of nonesterified plant sterols, which they in turn found to beneficially impact cholesterol levels.
 
Published in a recent issue of the journal Nutrition, Metabolism and Cardiovascular Diseases, the double blind study titled,^“The effect of high-fiber rye bread enriched with nonesterified plant sterols on major serum lipids and apolipoproteins in normocholesterolemic individuals,” initially monitored 68 trial subjects who were randomized to receive 9.3 grams per day of rye bread with 2 grams per day of added plant sterols. In the second phase of the study the amount of rye bread was doubled providing 18.6 grams per day of fiber and in the active group 4 grams per day of plant sterols. Cholesterol levels were monitored using a novel rye fiber-derived biomarker in plasma.
 
The researchers found that test subjects who ingested the rye bread enriched with 2 grams per day of plant sterols during two weeks experienced a significant reduction in serum total and LDL cholesterol, apoB/apoA1 and total cholesterol/HDL cholesterol ratios by 5%, 8%, 8% and 7%, respectively, compared to controls.
 
The test subjects who followed the second phase of the trial and ingested rye bread with 4 grams per day of plant sterols experienced a 6.5%, 10%, 5.5% and nearly 4% difference compared to controls, being most pronounced for LDL (0.33 mmol/L).
 
According to Päivi Söderholm, PhD, a researcher at the Folkhälsan Research Center, Biomedicum Helsinki, at the University of Helsinki in Finland, at first the team was unsure if rye bread was an ideal carrier for the phytosterols. The primary concern was whether rye fiber would interact with plant sterols and inhibit the cholesterol-lowering action.
 
“Rye bread is fat-free, so it seemed to be an appropriate environment for the non-esterified (less fat-soluble) form of plant sterols we were using,” said Dr.  Söderholm. “However, we did not know whether rye bread was suitable food carrier for added plant sterols, thus delivering and releasing the plants sterols into the intestine where the cholesterol lowering action takes place. We wanted to investigate whether the LDL cholesterol-lowering properties of plant sterols were still effective when the carrier was high-fibre rye bread.”
 
Dr.  Söderholm said she was surprised at just how effective the treatments were when it came to the effect of the sterols on the study subjects. “Our subjects were healthy and considered as normocholesterolemic (mean total cholesterol 5.1 mmol/L), therefore we were slightly surprised by the efficacy of cholesterol reduction,” she said. “We also observed a significant decrease in another important risk factor; apolipoprotein B/apolipoprotein A1-ratio (the balance between proatherogenic and antiatherogenic lipoproteins), which further convinced us of the importance of this outcome.”
 
In terms of how their research might potentially impact future consumers, Dr.  Söderholm said the likelihood of formulating a sterol-enriched rye bread targeted to address high cholesterol is entirely feasible. “Our results indicated that by replacing some of the dietary cereals [on a daily basis] (for example refined wheat bread) with plant sterol-enriched high-fibre rye bread LDL-cholesterol could be reduced without other modifications in habitual diet,” she said. “For the average consumer this kind of dietary modification could be easy to implement. We assume that consuming rye-based foods also provokes other health effects that can be seen in the long run. Therefore, there could be an occasion for high-fiber rye-based plant sterol supplemental foods in the market for cholesterol-lowering purposes, simultaneously providing also other advantages of rye.”
 
But before any of those ideas can come to fruition, Dr. Söderholm said there is much more research to be done. “There are still some laboratory analyses to be done on these samples to find other interesting indicators of health effects of rye/plant sterols,” she said. “When we have all the data we can evaluate the details we want to focus on next.”