RANDOMIZED CONTROLLED TRIAL OF EFFECT OF FRUIT AND VEGETABLE CONSUMPTION ON PLASMA-CONCENTRATIONS OF LIPIDS AND ANTIOXIDANTS

Objectives: To determine the extent to which plasma antioxidant concen trations in people with habitual low intake of fruit and vegetables re spond to increased intakes of these foods. To examine whether advice t o increase fruit and vegetables will result in reduction of concentrat ions of total and low density lipoprotein cholesterol. Design: Randomi sed controlled trial in which intervention and control groups were fol lowed up for eight weeks. The intervention group was asked to consume eight servings of fruit and vegetables a day. Setting: Dunedin, New Ze aland. Subjects: Eighty seven subjects with normal lipid concentration s who ate three or fewer servings of fruit and vegetables daily. Main outcome measures: Plasma concentrations of vitamin C, retinol, alpha a nd beta carotene, alpha tocopherol, lipids, and lipoproteins. Dietary intake assessed with diet records over four days. Results: The mean pl asma vitamin C, alpha carotene, and beta carotene concentrations incre ased in parallel with increased dietary intake of fruit and vegetables in the intervention group. Concentrations of retinol, alpha tocophero l, lipids, and lipoproteins remained unchanged despite some increase i n dietary vitamin E and a small reduction in saturated fat intake. Con clusions: Following a recommendation to increase fruit and vegetable c onsumption produces change in plasma concentrations of vitamin C, alph a carotene, and beta carotene likely to reduce incidence of cancer. Mo re specific dietary advice to modify fat intake may be necessary to re duce the risk of cardiovascular disease mediated by lipoprotein and vi tamin E.