Orange juice decreases low-density lipoprotein cholesterol in hypercholesterolemic subjects and improves lipid transfer to high-density lipoprotein in normal and hypercholesterolemic subjects

Abstract

Orange juice (OJ) is regularly consumed worldwide, but its effects on plasma lipids have rarely been explored. This study hypothesized that consumption of OJ concentrate would improve lipid levels and lipid metabolism, which are important in high-density lipoprotein (HDL) function in normolipidemic (NC) and hypercholesterolemic (HCH) subjects. Fourteen HCH and 31 NC adults consumed 750 mL/day OJ concentrate (1:6 OJ/water) for 60 days. Eight control subjects did not consume OJ for 60 days. Plasma was collected before and on the last day for biochemical analysis and an in vitro assay of transfers of radioactively labeled free-cholesterol, cholesteryl esters, phospholipids, and triglycerides from lipoprotein-like nanoemulsions to HDL. Orange juice consumption decreased low-density lipoprotein cholesterol (160 ± 17 to 141 ± 26 mg/dL, P < .01) in the HCH group but not in the NC group. HDL-cholesterol and triglycerides remained unchanged in both groups. Free-cholesterol transfer to HDL increased (HCH: 4.4 ± 2 to 5.6 ± 1%, NC: 3.2 ± 2 to 6.2 ± 1%, P< .05) whereas triglyceride (HCH 4.9 ± 1 to 3.1 ± 1%, NC 4.4 ± 1 to 3.4 ± 1%, P< .05) and phospholipid (HCH 21.6 ± 2 to 18.6 ± 3%, NC 20.2 ± 2 to 18.4 ± 2%, P < .05) transfers decreased in both groups. Cholesteryl-ester transfer decreased only in HCH (3.6 ± 1 to 3.1 ± 1%, P < .05), but not in NC. In control subjects, plasma lipids and transfers were unaltered for 60 days. Thus, by decreasing atherogenic low-density lipoprotein cholesterol in HCH and increasing HDL ability to take up free cholesterol in HCH and NC, OJ may be beneficial to both groups as free-cholesterol transfer to HDL is crucial for cholesterol esterification and reverse cholesterol transport.