Human Nutrition and Metabolism Consumption of Watermelon Juice Increases Plasma Concentrations of Lycopene and -Carotene in Humans

Watermelon is a rich natural source of lycopene, a carotenoid of great interest because of its antioxidant capacity and potential health benefits. Assessment of bioavailability of lycopene from foods has been limited to tomato products, in which heat processing promotes lycopene bioavailability. We examined the bioavailability of lycopene from fresh-frozen watermelon juice in a 19-wk crossover study. Healthy, nonsmoking adults (36–69 y) completed three 3-wk treatment periods, each with a controlled, weight-maintenance diet. Treatment periods were preceded by “washout” periods of 2–4 wk during which lycopene-rich foods were restricted. All 23 subjects consumed the W-20 (20.1 mg/d lycopene, 2.5 mg/d -carotene from watermelon juice) and C-0 treatments (controlled diet, no juice). As a third treatment, subjects consumed either the W-40 (40.2 mg/d lycopene, 5.0 mg/d -carotene from watermelon juice, n 12) or T-20 treatment (18.4 mg/d lycopene, 0.6 mg/d -carotene from tomato juice, n 10). After 3 wk of treatment, plasma lycopene concentrations for the W-20, W-40, T-20 and C-0 treatments were (least squares means SEM) 1078 106, 1183 139, 960 117 and 272 27 nmol/L, respectively. Plasma concentrations of -carotene were significantly greater after W-20 (574 49 nmol/L) and W-40 (694 73 nmol/L) treatments than after the C-0 treatment (313 27 nmol/L). Plasma lycopene concentrations did not differ at wk 3 after W-20, W-40 and T-20 treatments, indicating that lycopene was bioavailable from both fresh-frozen watermelon juice and canned tomato juice, and that a dose–response effect was not apparent in plasma when the watermelon dose was doubled. J. Nutr. 133: 1043–1050, 2003.