The first orange juice containing sterols was launched at the end of last year on the US market, developed by Coca-Cola's Minute Maid brand using Cargill's plant sterol ingredient CoroWise.

The new results, based on a 10-week study of 72 healthy volunteers with mildly elevated cholesterol levels, are thought to be the first to show the cholesterol-reducing effects of plant sterols in a non-fat beverage.

"Fortifying orange juice with plant sterols is an easy and effective way to boost a diet's LDL-fighting power in individuals with mildly elevated cholesterol levels," said Sridevi Devaraj, an assistant professor of pathology at the University of California Davis Medical Center who led the sterol study.

"The inclusion of sterols in orange juice offers an important treatment option without increasing saturated fat and at the same time providing vitamin C, flavonoids and other essential nutrients,"

Cholesterol is a key component in the development ofartherosclerosis, the accumulation of fatty deposits on the inner lining of arteries. Mainly as a result of this, cholesterol increases the risks of heart disease, stroke and other vascular diseases.

According to the World Health Organisation, almost one fifth (18 per cent) of global stroke events (mostly nonfatal events) and about 56 per cent of global heart disease are attributable to total cholesterol levels above 3.2 mmol/l. This amounts to about 4.4 million deaths (7.9 per cent of the total) and 2.8 per cent of the global disease burden.

For the study, partly funded by Coca-Cola, researchers enrolled healthy volunteers aged 20 to 73 with mildly elevated cholesterol levels. The volunteers were asked to eat their normal diet but to drink a cup of juice along with whatever they had for breakfast and dinner. Half of the group had the sterol-fortified orange juice while the others drank regular orange juice by the same manufacturer.

Fasting blood tests were taken before and after the study to determine total cholesterol, total triglyceride, LDL cholesterol, high-density lipoprotein cholesterol and apolipoprotein B levels.

Volunteers who drank the sterol-fortified orange juice had a 7.2 per cent decrease in total cholesterol, 12.4 per cent decrease in LDL cholesterol, and 7.8 per cent decrease in non-high-density lipoprotein levels compared to baseline and to the group that received the non-sterol orange juice group, said the researchers in the March 8 issue of the journal Arteriosclerosis, Thrombosis and Vascular Biology .

"Orange juice has wide appeal since it is consumed by individuals of all ages, from early childhood to old age. And for individuals who do not want to take a drug for mildly elevated cholesterol, this may provide a healthy and attractive alternative," said Devaraj.

Previous studies at other institutions have evaluated plant sterols in yoghurt and other low-fat and non-fat foods, with variable results. The UC Davis study may be unique in that it did not place volunteers on a special diet and only asked that they drink the juice with their normal meals.

"The fat in the meals may have helped to emulsify the sterols, but further research will need to be done to determine the meal's relevance," said Ishwarlal Jialal, professor of pathology and internal medicine and director of the Laboratory for Atherosclerosis and Metabolic Research at UC Davis Medical Center.

"We also would like to investigate whether sterols can add to the LDL-reducing effects of statin drugs in higher-risk individuals," he added.

The phytosterols market is growing due to strong research showing the benefits of the ingredient and a recently approved heart health claim helping to raise the profile of the natural compounds. The American Heart Association and National Cholesterol Education Program recommends a diet that is low in saturated fat and cholesterol and rich in soluble fiber and plant sterols to help individuals reduce their risk of heart disease.

Meanwhile Minute Maid has added three new flavors to its line of low-calorie juice drinks targeted at consumers counting calories or carbs. The company already markets a Light Lemonade, said to be the number one light juice drink brand, outselling competition two to one.