Portfolio Diet - Cholesterol Lowering Foods

Portfolio Diet is a therapeutic vegetarian diet created by Canadian researcher David Jenkins in 2003 to lower blood cholesterol. This diet emphasizes using a portfolio of foods or food components that have found to associate with cholesterol lowering to enhance this effect. Viscous fiber, soy protein, plant sterols, and nuts are the four essential components of Portfolio diet. This diet is low in saturated fat, high in fibre. Researches have found it has comparable blood cholesterol effect to statin treatment.

Background

Heart disease is the leading cause of death in the United States. Several risk factors, such as high blood pressure, high blood cholesterol, overweight or obese, smoking, have been identified to promote the cardiovascular diseases. American Heart Association (AHA) and American College of Cardiology (ACC) have suggested life style management to control risk factors in order to reduce cardiovascular risk. One of the strategies is reducing dietary saturated fat intake to reduce blood low-density lipoprotein (LDL) which is considered as “bad” blood cholesterol. If dietary and life style management is ineffective, medication such as statin will be used to in conjunction to reduce blood cholesterol levels. Soy protein, nuts, viscous fibre, and plant sterols have been found to have cholesterol lowering effect. The U.S. Food and Drug Administration has approved health claim for these foods. David Jenkins believes including all of these foods in the diet is able to achi eve better cholesterol lowering results.

Diet

Typical portfolio diet includes about 50 grams nuts, such as walnuts, peanuts, almond, 2 grams plant sterols, 10-25 grams viscous fibre, coming from oats, barleys, psyllium, and 50 grams soy protein per day.

Studies

The first Portfolio diet study was conducted in 2002. The study compared the effect of cholesterol lowering effect using the portfolio diet versus Lovastatin. This is a randomized control trial. 46 healthy individuals with high blood cholesterol levels were randomly assigned into one of three study groups: 1. Diet low in saturated fat (Control group) 2. Same diet as 1 plus statin 3. A diet high in plant sterols, soy protein, viscous fibre, almond (diet portfolio) for a month. LDL level was reduced significantly in both the statin group and the diet portfolio group. There is no significant difference in the efficacy between these two groups. It concluded that diet portfolio has comparable cholesterol-lowering effect to statin treatment.

The second study occurred between 2007 and 2009. It examined the effect of adding monounsaturated fatty acid to dietary portfolio of cholesterol-lowering foods in hyperlipidemia. 24 hyperlipidemic females followed diet low in saturated fat for a month, then they were randomly placed into a dietary portfolio low or high in monounsaturated fatty for another month. They found patients who consumed the dietary portfolio high in monounsaturated fatty acid had lower LDL level and higher high- density lipoprotein (HDL) level. Patients who consumed the dietary portfolio low in monounsaturated fatty had no change in HDL level. It concluded that using dietary portfolio high in monounsaturated fatty acid is able to further reduce cardiovascular risk by increasing.

The third study was a parallel-design study of 351 hyperlipidemic patients across Canada between 2007 and 2009 to 1 to 3 treatments lasting for 6 months. Patients received dietary advice on either a low saturated fat diet or a dietary portfolio including soy protein, nuts, viscous fibre, and plant sterols. Routine dietary portfolio group received 2 clinic visits and intense dietary portfolio group received 7 clinic visits in 6 months. They found LDL in two dietary portfolio groups were significantly lower than the control group (diet low in saturated fat) and there is no difference between the regular dietary portfolio group and intense group.