Increasing vegetable and fruit intake: Randomized intervention and monitoring in an at-risk population

High vegetable and fruit (V&F) consumption has been associated with a lower risk of several cancers. However, little is known about the ability of ind ividuals to increase their intakes markedly. In this 1-year randomized, controlled diet intervention study of men and wo men with a recent history of adenomas, the intervention group (n = 100) was asked to increase V&F intake to at least eight servings per day; the contr ol group (n = 101) continued eating their usual diet. End-point measures in cluded V&F intake assessed by 3-day diet records, plasma carotenoids, serum lipids, urinary sodium and potassium, and body weight. The intervention group increased their daily V&F intake an average of 5.5 s ervings over 1 year; the control group had an average decrease of 0.5 servi ngs per day (P < 0.001). Plasma total carotenoids, alpha-carotene, beta-car otene, beta-cryptoxanthin, and lutein/zeaxanthin were each statistically si gnificantly elevated over baseline (11-54%) in the intervention group compa red with the control group over the duration of follow-up (P < 0.001). Urin ary potassium excretion was elevated 14% over baseline in the intervention group compared with no change in the control group (P < 0.001). Modest decr eases in the intervention but not the control group were observed for total and low-density lipoprotein cholesterol. Plasma lycopene, triglycerides, h igh-density lipoprotein cholesterol, body weight, and urinary sodium were n ot affected by the intervention. V&F intake was significantly increased in this motivated population at high er risk of colon cancer and maintained for at least 12 months, as assessed using diet records and an ensemble of biomarkers.