Eating a diet high in soy protein, viscous fibre, almonds and plant sterols is as effective in managing cholesterol as taking a starting dose of cholesterol-lowering drugs, a study to be published tomorrow in the Journal of the American Medical Association (JAMA) will report.
Known as the 'Portfolio' eating plan, this dietary approach also lowered c-reactive protein levels, an indication of inflamed arteries and a risk factor for heart disease, in individuals who followed the plan more than in the patients taking cholesterol-lowering statins.
The third in a series of Portfolio studies, the researchers say this is the first study to directly compare patients on first-line statins to those on the diet. Patients on the Portfolio eating plan lowered their LDL ('bad') cholesterol up to 32 per cent, and on average 29 per cent in four weeks.
For one month, the study directly compared three randomised groups of patients with high cholesterol. One group of 16 people ate the National Cholesterol Education Program's step 2 diet, which is a very low-saturated fat diet based on whole-wheat cereals and low-fat dairy foods. Another group of 14 people ate this diet in addition to taking a 20 milligram lovastatin, a cholesterol-lowering drug, each day. And a third group of 16 people ate a Portfolio eating plan high in plant sterols, soy protein, viscous fibres and almonds.
Fasting blood samples, blood pressure, and body weight were obtained at weeks zero, two and four.
For the statin and Portfolio groups, the drop in LDL cholesterol was described as comparable, with no significant differences - there was a 31 per cent drop for the statin group and a 29 per cent drop for the Portfolio group. However, for the Step 2 (control) group the researchers recorded a reduction of just 8 per cent.
Patients on the Portfolio diet ate foods with viscous fibre, such as oat bran, barley, okra and aubergine, as well as taking the drug Metamucil; plant sterol-enriched margarines such as Benecol or Take Control, beans (especially chickpeas) and olive oil; and soy protein in forms such as tempeh, tofu and Boca meatless 'chicken' and 'hamburger' patties.
Among these choices, the researchers noted that the five most popular foods among study participants were almonds, ground soy, oat bran cereal, oat bran bread and plant sterol margarine.
"For the most part, research on dietary changes has resulted in only modest reductions in cholesterol, and diet has been considered by some as relatively ineffective," said study leader Dr David Jenkins of the Clinical Nutrition and Risk Factor Modification Center at St Michael's Hospital in Toronto and the University of Toronto's Department of Nutritional Sciences, Faculty of Medicine."But on their own, these heart healthy types of foods have been studied individually and recognised by the Food & Drug Administration [FDA] for their cholesterol-lowering effects."
He continued: "This research showed that when we combined these heart-healthy foods into one eating plan, the effect was equal to that of the starting dose of statins, or cholesterol-lowering drug therapy - and yielded better results than previous dietary recommendations for cholesterol reduction." Jenkins also noted that these results support recommendations that dietary intervention should be the first line of therapy for high cholesterol.
In addition he remarked that for someone not needing a dramatic reduction in their LDL cholesterol level, but merely a moderate drop or to maintain a healthy heart, this study may indicate the benefit of incorporating just some of these foods each day, or making some new, heart-healthy substitutions.
"The easiest substitutions to try might include a snack of almonds instead of popcorn, pretzels or potato chips, or a soy burger instead of a regular burger," he suggested.
Full details of the study can be found in the Journal of the American Medical Association 23 July, 2003.