new study conducted by researchers at the Stanford University Medical Center suggests a low-fat diet rich in vegetables, fruits, whole grains and beans has twice the cholesterol-lowering power of a conventional low-fat diet.

Led by Christopher Gardner, the researchers compared two patient groups eating different foods but identical amounts of total and saturated fat, protein, carbohydrate and cholesterol.

The conventional diet: Focused solely on avoiding harmful saturated fat and cholesterol with foods, like frozen waffles and turkey bologna sandwiches.

The second diet: Included the same proportions of fat and cholesterol plus lots of plant-based foods, like hot grain cereals and vegetable soups.

Both diets lowered total and low-density lipoprotein (LDL, or 'bad') cholesterol over the course of the four-week study. The conventional diet produced, on an average, a 4.6 percent LDL decrease, but the plant-based diet achieved a 9.4 percent decrease in LDL.

"We hope people appreciate the new American Heart Association Guidelines," says Gardner.

Some guidelines: Include more whole grains and vegetables, beans and colours -- not iceberg lettuce, but red bell peppers, carrots, broccoli and red cabbage and the really colorful foods.

They are low in saturated fat and cholesterol. They are high in other nutrients and phytochemicals that are good for you.