Grapes tend to be a simple and easy snack where not much thought or preparation needs to be given. At the University of Nevada, Reno, though, researchers have given much thought to grapes, in particular the extract made from the seeds, and their use as a way to lower cholesterol and so far, their studies show a positive effect.
Within the walls of the Max Fleishmann Agriculture building, Assistant Professor Marie-Louise Ricketts and her team of students are focused on an extract made from the seeds, which are rich in procyanidins. Procyanidins are water-soluble plant pigments that are naturally present in vegetables, fruits and beverages such as wine and tea.
The results of the studies being conducted at the University on grape seed extract, which is made from the seeds of white grapes, show that it acts in the body to exert a protective effect, lowering serum cholesterol and triglyceride levels in healthy rodents, as well as significantly reducing abnormally high triglyceride levels and fatty liver disease in a rat model.
"I started working on this project a few years ago when I was a post-doctoral Fellow at Baylor College of Medicine," Ricketts, in the Department of Agriculture, Nutrition and Veterinary Sciences, said. "It was a collaboration with a Spanish-based research group that had done some initial studies in rats. And when I came to the University, my interest in investigating the molecular effects of dietary components expanded."
The research being conducted in the lab aims to further determine the underlying mechanisms used by grape seed procyanidin extract to lower cholesterol and triglyceride levels, the main perpetrators of increasing lipids (a type of fat) in humans and other animals.
Diets that are rich in fruits and vegetables tend to be high in procyanidins, which can exert cardioprotective effects in humans. While dietary procyanidins are commonly found in grapes and apples, and have been known to reduce the risk for cardiovascular disease, the aim of this research is to focus on identifying the ways in which grape seed procyanidin extract functions. Since it is a rich source of low molecular weight procyanidins, grape seed extract can be easily absorbed in the digestive tract and taken into the body.
Why it is important to overall health
Currently, cardiovascular disease is the leading cause of death in the U.S. and around the world.
Obesity is also a major health concern that is reported to affect 78.6 million adults in the U.S., with increasing incidence among children. Obesity is a disorder in which there is an excessive amount of fat in the body.
"Reducing serum cholesterol and triglyceride levels is important in order to prevent cardiovascular disease," Ricketts said. "If you can find a natural compound that can decrease these, it's a good thing because it's easier to consume. More importantly, although there is increasing incidences of non-alcoholic fatty liver disease, in both adults and children, there is currently no effective treatment. Finding something from dietary sources that will reduce fat accumulation in the liver is an important area of research."
Ricketts explained how natural compounds tend to be safer as they work with the entire body as opposed to pharmaceutical drugs that target and help only one area of the body, but may be bad for another part, leading to complicated side effects.
"Procyanidins are important compounds within the diet," Ricketts said. "By eating foods that are rich in these compounds, nature provides us with what we need. In nature, these types of compounds tend to be more flexible rather than a synthetic compound that is made to target a particular receptor, for example."
So far, no well-controlled studies have been conducted in humans in order to test the effectiveness of grape seed extracts in the body to combat risk factors associated with cardiovascular disease. But, Ricketts said, they are laying the foundation through their observations in rodent models.
"Controlled studies, using grape seed extracts, still need to be done on humans, but before that can happen, we need to better understand how they function at the cellular and molecular level," she said. "Our work is helping to identify mechanisms by which it can exert beneficial effects, so understanding this will allow more appropriately controlled experiments to be performed, such as whether the health status of an individual and their diet could affect whether there are likely to be positive effects observed by taking grape seed extracts."
Originally from Wigan, England, Ricketts received her bachelor's degree in biomedical science from Sheffield Hallam University, England. She then went on to obtain her doctorate in medicine from the University of Birmingham, England. Her post-doctoral work led her to Université Laval in Quebec City, Canada, and another post-doctoral fellowship at Baylor College of Medicine.
Ricketts is extremely passionate about her work, and continues to work on this project a decade after beginning it.
"I really believe that procyanidins are nature's medicine and the fact that these compounds are present in the diet and exert such affects at the molecular level is really fascinating," she said. "Learning more about these compounds from our studies makes them all that more intriguing and provides more avenues for continued investigation."