Aug. 23, 2011 -- A diet that incorporates cholesterol-lowering foods like soy, nuts, and plant sterols may work better at lowering cholesterol levels than a traditional low-fat diet.
A new study shows that people with high cholesterol who followed the portfolio diet, which includes a combination of cholesterol-lowering foods, lowered their low-density lipoprotein (LDL) cholesterol levels by about 13% after six months on the diet. That's compared with a 3% LDL reduction among those who followed a traditional diet low in saturated fat.
"Given that cardiovascular disease is our major killer, we feel that a lot of people will benefit to a greater or lesser extent by adopting this diet, which is basically a plant-based approach," says researcher David Jenkins, MD, Canada Research Chair at the University of Toronto. "Those who may want to follow the diet more specifically are those who are on the cusp for statin treatment."
"If we let people know that they can control their own cholesterol levels themselves, we're putting some of the responsibility but also the power back into the hands of ordinary citizens," Jenkins tells WebMD.
Portfolio Diet Lowers Cholesterol
The portfolio diet includes four types of foods recognized by the FDA for their ability to lower cholesterol:
- Soy protein. The portfolio diet calls for substituting soy-based meat products for meat, such as soy burgers, soy hot dogs, and soy cold cuts. Soy milk and soybeans (also known as edamame) are also good sources of soy protein.
- Sticky fiber. The diet incorporates fiber from oats, barley, and psyllium.
- Plant sterol esters. The diet replaces butter and margarine with plant sterol ester-enriched margarine.
- Nuts. A handful a day of tree nuts, such as almonds or walnuts, and peanuts are included in the diet.
In the study, researchers compared the effectiveness of the portfolio diet to a traditional low-fat diet in lowering LDL cholesterol in 351 people with high cholesterol. The results appear in the Journal of the American Medical Association.
The people were randomly divided into three groups that received counseling about the portfolio diet in two sessions or a more intensive seven sessions over a six-month period or followed a standard low-fat diet for six months.
The study showed that the regular and intensively counseled portfolio diet group both experienced a reduction in LDL cholesterol of about 13% compared with a 3% reduction in the low-fat diet group.
Jenkins says the study suggests that the mix of plant-based foods included in the portfolio diet can achieve cholesterol-lowering results similar to what can be achieved through drugs.
Motivation Key to Results
But what experts say is most surprising about the study is that one counseling session every three months was nearly as effective as monthly diet counseling sessions in helping people lower their cholesterol.
"The really remarkable result is that these cholesterol-lowering results were achieved after only a couple of counseling sessions," says Mike Miller, MD, professor of medicine, epidemiology and public health at the University of Maryland. "We don't usually see these kinds of results."
Miller says the next question will be whether these results can be maintained beyond the first six months of the diet and whether people can stay motivated to stick to the diet.
Registered dietitian Jeannie Gazzaniga-Moloo, PhD, RD, agrees.
"It could be quite possible that there may be something very straightforward about the portfolio diet that people are able to follow and gain this effect," says Gazzaniga-Moloo, a spokeswoman for the American Dietetic Association. "But in my practice, getting people to change from animal to soy protein can be quite a challenge, and people need encouragement."
Gazzaniga-Moloo says people tend to respond to positive dietary messages, and one advantage of the portfolio diet is that it says, "Let's bring in nuts, legumes, and plant sterols."
"That is something proactive, rather than just taking the saturated fat out of the diet," she tells WebMD. "It's quite possibly why the diet is so well accepted."