β-Carotene and α-tocopherol in healthy overweight adults; depletion kinetics are correlated with adiposity

Abstract

Healthy overweight subjects (24 males, 68 females; mean age=48.8 years; body mass index=27.1±4.9) participated in a randomized, double-blind, placebo-controlled crossover study with two periods of 28-day supplementation using a nutritional product composed primarily of dehydrated juice concentrates from mixed fruits and vegetables (JuicePlus +^®). Compared with placebo, supplementation for 28 days increased concentrations of serum β-carotene by 264% (P <0.001) and α-tocopherol by 14% (P < 0.01). After crossover of the active group to placebo, β-carotene and α-tocopherol declined via first-order kinetics, with serum half-lives (t_1/2) for β-carotene and α-tocopherol determined to be 22.8±3.1 and 4.6±2.3 days, respectively. Depletion rates for β-carotene correlated with adiposity (quartile 1, body mass index=21.96, t_1/2=17.6 days vs. quartile 4, body mass index=37.87, t_1/2=26.3 days; P < 0.05). In conclusion, the supplementation period resulted in significantly elevated levels of β-carotene and α-tocopherol, indicating bioavailability. These increased levels persisted 2–4 weeks after supplementation was discontinued, and the rates of depletion were correlated with the levels of general adiposity.

• β-Carotene
• α-tocopherol
• half-life
• body mass index
• fruit
• vegetable