Getting to the heart of the positive power of red wine

With cardiovascular disease still ranked as the leading cause of death in Australia, researchers at UniSA’s Nutritional Physiology Research Centre (NPRC) are embarking on a new study to look more closely at the potential of polyphenols found in red wine in reducing the risk of cardiovascular disease.

The possible link between red wine and heart health was first noted as far back as 1819 when researchers noticed that, despite a diet rich in saturated fats, the French appeared to suffer less from heart disease.

Coined the French Paradox in 1992, this early research sparked a huge spike in sales of red wine worldwide. Since then the early research has been brought into question, leading to more detailed investigations of what properties of red wine might actually have heart protective qualities.

One major risk factor for fatal and non-fatal cardiovascular disease is progressive increase in blood pressure. This makes early detection and intervention a priority in any bid to reduce cardiovascular disease mortality and morbidity.

Project coordinator at UniSA’s NPRC Dr Narelle Berry says that the antioxidant resveratrol, found in the skin of red grapes, may be a key ingredient in red wine that improves heart health.

“However the evidence is still fairly basic and more research is needed to really pin down the benefits,” she said.

Dr Berry is currently investigating acute effects of Resveratrol on the relaxation of blood vessels which may influence blood pressure at rest and during exercise.

“Even with people who have only marginally elevated blood pressure when they are at rest, impaired blood vessel function can trigger exaggerated rises during exercise or in response to other simple stresses,” she said.

“Individuals with exaggerated blood pressure responses to exercise are at risk of developing hypertension. What’s more, the exaggerated responses can place tremendous stress on the heart.

“Our aim is to find out if resveratrol, by improving blood vessel function, can ease the blood pressure responses to exercise.”

The centre is now calling for research volunteers.

“We need to identify suitable volunteers to help with this study,” Dr Berry said.

“We’re looking for overweight men or postmenopausal women aged between 30 to 70 years with borderline high blood pressure who are not taking blood pressure lowering medication and are otherwise healthy.”

Volunteers will be screened to check that their weight and blood pressure is in the required range. Those eligible will be asked to come into the centre for a 2 hour visit each week for four weeks. During the visit they will take a Resveratrol supplement and blood flow changes in the arm will be assessed using ultrasound. A blood sample will also be taken before volunteers undergo a short exercise bike test in which blood pressure will be monitored continuously using a cuff around the finger.

(Source: University of South Australia: March 2009)