The study, published in Nutrition Research suggests that consumption of concentrated orange juice, known to contain high levels of flavonoids, may reduce levels of LDL cholesterol in people with high cholesterol levels, and may also benefit the lipid profile of all people by increasing free cholesterol transfer.
“Considering the results of this study, the effects of orange juice consumption can be considered beneficial to both subjects with normal lipids and those with hypercholesterolemia,” wrote the authors, led by Thais Cesar from Sao Paulo State University, Brazil.
The researchers reported that orange juice consumption has become a worldwide dietary habit, and stated that the consumption of concentrated juice has increased steadily over the years.
Concentrated orange juice is known to have a greater flavonoid content; such as polymethoxylated flavones (PMF), hesperitin and naringin, when compared to fresh orange juice.
Such differences are due to the manufacturing process which uses the entire fruit to produce concentrated juice, therefore meaning pectin and essential oils contained in the peel are also found in concentrate.
Previous studies have shown supplementation with PMF, hesperitin, and naringin to reduce low-density lipoprotein (LDL) cholesterol, and triglycerides. Whilst studies involving orange juice consumption or orange extract of flavonoids have also reported beneficial effects on plasma lipids.
However, the authors stated that despite the great importance of orange juice as a widely consumed dietary item, its effects on serum lipids have rarely been investigated.
The new study investigated whether consumption of orange juice concentrate would improve lipid levels and lipid metabolism, which are important in high-density lipoprotein (HDL) function in normolipidemic (normal lipid profile) and hypercholesterolemic (high cholesterol) subjects.
Orange juice consumption was reported to decreased low-density lipoprotein cholesterol (LDL) in the hypercholesterolemic group but not in the normolipidemic group. However, HDL-cholesterol and triglycerides were observed to remain unchanged in both groups.
The researchers reported free-cholesterol transfer to HDL increased in both groups, whereas triglyceride and phospholipid transfers decreased.
In normolipidemic subjects, orange juice intake was reported to elicit a 48 per cent increase in free cholesterol transfer and nine per cent decrease in the transfer of phospholipids.
For the hypercholesterolemic group, free cholesterol transfer increased by 22 per cent; whereas the phospholipid transfer decreased 10 per cent and triglyceride transfer reduced by 23 per cent after orange juice consumption.
The authors concluded that orange juice consumption “leads to a reduction of LDL-cholesterol in hypercholesterolemic subjects, an effect that is undoubtedly anti-atherogenic.”
Source: Nutrition Research
Volume 30, Issue 10, Pages 689-694, doi: 10.1016/j.nutres.2010.09.006
“Orange juice decreases low-density lipoprotein cholesterol in hypercholesterolemic subjects and improves lipid transfer to high-density lipoprotein in normal and hypercholesterolemic subjects”
Authors: T.B. Cesar, N.P. Aptekmann, M.P. Araujo, C.C. Vinagre, R.C. Maranhão