Orange juice fortified with plant sterols lowers bad cholesterol

(SACRAMENTO, Calif. USA) – Plant sterols — recognized for their cholesterol-lowering power when added to margarines, salad dressings and other fats — are just as effective in reducing low-density lipoprotein, or ‘bad’ cholesterol’ levels, when added to orange juice, say researchers at UC Davis School of Medicine and Medical Center.

The results, based on a 10-week study of 72 healthy volunteers with mildly elevated cholesterol levels, are published in the March 8 issue of the American Heart Association’s journal Arteriosclerosis, Thrombosis and Vascular Biology (available online at http://www.atvbaha.org).

‘Lowering LDL cholesterol is a well-accepted means of reducing the likelihood of heart disease,’ said Sridevi Devaraj, an assistant professor of pathology and investigator in the Laboratory for Atherosclerosis and Metabolic Research at UC Davis Medical Center who led the sterol study.

‘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.

‘Fifty percent of Americans have mildly elevated cholesterol levels, defined as having a total cholesterol reading of more than 200 mg/dL. 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.’

The American Heart Association and National Cholesterol Education Program recommend 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. Read more

Fruit Flies Can Shed Light On High Cholesterol, Obesity In Humans

How do fruit flies get high cholesterol and become obese? The same way as people do – by eating a diet that’s too rich in fats.

More importantly, according to two new studies led by a University of Utah human geneticist, fruit flies use the same molecular mechanisms as humans to help maintain proper balances of cholesterol and a key form of stored fat that contributes to obesity. The findings mean that as researchers try to learn more about the genetic and biological processes through which people regulate cholesterol and fat metabolism, the humble fruit fly, also called Drosophila, can teach humans much about themselves.

“Not a lot is known about these regulatory mechanisms in people,” says Carl S. Thummel, Ph.D., professor of human genetics at the U of U School of Medicine and senior author on the two studies. “But we can learn a lot by studying metabolic control in fruit flies and apply what we learn to humans.”

High cholesterol and obesity, which affects an estimated 25 percent to 30 percent of the U.S. population, are linked to heart disease, diabetes, and other diseases that take huge tolls on health and add billions of dollars to the nation’s medical bills. Understanding the processes that regulate cholesterol and fat in humans could be critical for addressing those health risks in people, Thummel believes.

The two studies identify a nuclear receptor, DHR96, which plays a critical role in regulating the balance or homeostasis of cholesterol and another fat molecule called triacylglycerol (TAG). Nuclear receptors are proteins that sense the presence of chemical compounds within cells. DHR96 corresponds closely to a nuclear receptor in humans, called LXR, that is known to regulate cholesterol levels.

In a study published Dec. 2 in Genes & Development, Thummel and colleagues at the U of U and two Canadian universities show that DHR96 helps regulate cholesterol in fruit flies by binding with this compound. When this binding occurs, it allows DNA to be read, which switches genes on and off that help maintain proper levels of cholesterol, according to Thummel, who also holds an H.A. and Edna Benning Presidential Endowed Chair in Human Genetics. Read more