A new study, published in the August 24/31 issue of JAMA, has found that a diet combining foods with cholesterol-lowering properties can reduce levels of low-density lipoprotein cholesterol (LDL-C) more effectively than a low saturated fat diet.

Two groups of people with high cholesterol were studied over a course of 6 months, one group was counseled to follow a diet consisting of cholesterol-lowering foods, such as nuts, plant sterols and soy protein, whilst the other group was counseled to follow a low-saturated fat diet. What they found was that the group following a diet combining cholesterol-lowering foods achieved a greater reduction in levels of LDL-C.

There has been a lot of focus on reducing serum cholesterol levels among individuals through enhancing conventional dietary therapy by including a combination of foods that contain cholesterol-lowering properties. However, there hadn’t been any assessment that compared the long-term health effects of conventional dietary advice to advice introducing cholesterol-lowering foods.

A multi-center trial was conducted by David J. A. Jenkins, M.D., and his colleagues of St. Michael’s Hospital and the University of Toronto, to see if the advice of following a dietary portfolio made up of foods considered effective – by the standard of the U.S. Food and Drug Administration – at reducing levels of serum cholesterol, would achieve better levels of LDL-C reduction than a control diet at a 6-month follow up.

An emphasis on high fiber and whole grains was made in the control diet, compared to the portfolio diet which included soy protein, plant sterols, nuts, and viscous fibers. The study was made across 4 academic centers in Canada (Vancouver, Winnipeg, Quebec City, and Toronto) with 351 participants, all with hyperlipidemia, who were randomly assigned to 1 of 3 treatments between June 2007 and February 2009.

The participants received dietary advice over the course of 6 months; the control group was assigned a low-saturated fat therapeutic diet whilst the other two groups received either a routine or intensive dietary portfolio, the difference between the two being the frequency at which counseling was delivered. The intensive dietary portfolio had 7 clinic visits over 6 months, compared to the routine portfolio which only involved 2 clinic visits.

The overall attrition rate of 345 participants in the modified intent-to-treat analysis didn’t vary that much between the different types of treatment, a rate of 26 percent for the control, 23 percent for the routine dietary portfolio and 18 percent for the intensive dietary portfolio.

The change in the levels of LDL-C over the course of 24 weeks were found to be -3.0 percent or -8 mg/dL in the control diet, -13.1 percent or -24 mg/dL in the routine dietary portfolio and -13.8 percent or -26 mg/dL for the intensive dietary portfolio.

The authors noted that the:

“Percentage LDL-C reductions for each dietary portfolio were significantly more than the control diet. The 2 dietary portfolio interventions did not differ significantly. Among participants randomized to one of the dietary portfolio interventions, percentage reduction in LDL-C on the dietary portfolio was associated with dietary adherence.”

They also added:

“In conclusion, this study indicated the potential value of using recognized cholesterol-lowering foods in combination. We believe this approach has clinical application. A meaningful 13 percent LDL-C reduction can be obtained after only 2 clinic visits of approximately 60-and 40-minute sessions. The limited 3 percent LDL-C reduction observed in the conventional diet is likely to reflect the adequacy of the baseline diet and therefore suggests that larger absolute reductions in LDL-C may be observed when the dietary portfolio is prescribed to patients with diets more reflective of the general population.”

Written by Joseph Nordqvist