It turns out your mother was right. You better eat your vegetables. You should also eat fruits, whole grains, and beans according to a Stanford University School of Medicine study. A low-fat diet rich in these "good-for-you foods" has twice the cholesterol-lowering power of a conventional low-fat diet.
The finding comes from a small but meticulous comparison of two low-fat diets. The meals were identical in total fat, saturated fat, protein, carbohydrate, and cholesterol content. But one diet, the conventional diet, focused solely on avoiding harmful saturated fat and cholesterol. People in this group dined on standard American low-fat foods such as frozen waffles and turkey bologna sandwiches. The second diet plan incorporated considerably more plant-based foods such as hot grain cereals, legumes, and vegetable soups.
Both diet plans lowered LDL ("bad") cholesterol levels. But the plant-based diet plan beat the conventional plan hands down -- with an average 9.4 percent decrease in LDL for the plant-based diet versus an average 4.6 percent decrease for the conventional plan. HDL ("good") cholesterol and triglyceride (blood fat) levels were the same for the two groups.
About the Study
The randomized clinical trial included 120 adults, ages 30 to 65. All were members of the target population for food-based approaches to lowering cholesterol: They had moderately high LDL levels, between 130 and 190 mg/dL. Researchers randomly divided the outpatients into two diners' groups: 61 ate the conventional diet, while 59 ate the plant-based diet. Each weekday for a month, they visited a research dining hall for a specially prepared, carefully weighed, chemically analyzed lunch or dinner.
The study required that participants maintain a constant weight so that any changes in blood cholesterol would be attributable to the diets themselves -- not to any changes in weight brought on by the diets. When changes in weight were observed, the participants' calories were changed accordingly to help them stay stable. In general, researchers tended to add calories to the meal plan over the course of the study as participants were observed to be more likely to lose weight than to gain weight on both diets.
The scientists also requested that no one change exercise habits, saying: "If you are a marathon runner, keep running marathons. But if you're a couch potato, we need you to stay a couch potato."
According to this study, our cholesterol levels will benefit if we eat a more plant-based diet -- with more whole grains, vegetables (but not iceberg lettuce), beans, and food with colors: red bell peppers, carrots, broccoli, and red cabbage. "The really colorful foods are all low in saturated fat and cholesterol, and really high in other nutrients and phytochemicals that are good for you," said Christopher Gardner, PhD, assistant professor of medicine at the Stanford Prevention Research Center and lead author on the National Institutes of Health-funded study.
Do You Have to Give Up Meat?
No. A "plant-based" diet is not necessarily a vegetarian diet. It simply includes a foundation of whole grains, vegetables, beans, nuts, seeds and fruits, and treats meat more like a condiment than a main dish. |
