Researchers working in biotechnology laboratories in Vienna have found that red wine contains favorable levels of a chemical found in drugs used treat type 2 diabetes patients. In time, they say, red wine treatments may offer an supplemental approach to current therapies.
The results of their research were published in the January issue of Food & Function. The team tested the chemical composition of two white wines from Austria and 10 reds. In the most promising experiment, 100 milliliters of a 2003 Blaufränkisch contained four times the ligands found in the the recommended daily dose of rosiglitazone, a commercially available drug used to treat type 2 diabetes, manufactured by GlaxoSmithKline and marketed as Avandia. Ligands are sticky molecules associated with preventing blood clots, reducing inflammation and optimizing cholesterol digestion.
Type 2 diabetes is a metabolic disease characterized by the body's inability to use insulin to regulate blood-sugar levels. Clinical studies on animals show that red wine may help protect against developing the disease. "However, the molecular modes of action and the different pathways involved are not yet fully understood for most of the active compounds present in red wines," wrote lead researcher Alois Jungbauer, a biotechnologist at Vienna’s University of Natural Resources and Life Sciences.
Ligands contain polyunsaturated fatty acids that bind to cholesterol in the body's tissues and transport it to the liver for excretion. The inability to get rid of cholesterol is a precursor to metabolic syndrome. "Metabolic syndrome is correlated with reduced insulin sensitivity, hypertension and hence a higher risk for development of type 2 diabetes and cardiovascular disease," wrote the authors. Regular doses of ligands could prevent metabolic syndrome and reduce the chances of type 2 diabetes.
Food & Function deputy editor Kathleen Too wrote in an accompanying editorial that the findings may provide a basis for a one-two punch against the risk of metabolic syndrome. "They found that not only did these compounds bind to [cholesterol], but that the wine contained enough of them to rival the activity of the potent drug rosiglitazone."
Not all wines are created equal in this regard, however. The aforementioned Blaufrankisch contained high levels of the chemicals, with 1.71 grams per liter. Second was a 2004 Zweigelt with 1.65 grams per liter. A 2005 Zweigelt contained less, which leads Jungbauer to conclude that different environmental conditions across vintages, as well as differing winemaking techniques, may greatly change the chemical profile of wine.
Nonetheless, none of the 10 reds contained less than 1 gram per liter of measurable polyphenols. The white wines, which are not exposed to grape skins for a prolonged period of time, contained below 0.10 grams per liter.
Chi-Tang Ho, a food researcher at Rutgers School of Environmental and Biological Sciences told Too that the results provide evidence to support moderate red wine consumption, but that the impact of alcohol on the body needs consideration. Those who wish to avoid alcohol may look to other sources rich in similar polyphenols, such as tea and certain fruits.
While red wine cannot be considered an alternative treatment to any of the above ailments, Jungbauer did not discount the power of alternative therapies in the future. "Grape skin extracts have great potential, and although the influence of ethanol is not yet fully understood, I am confident that it will be possible to replace some synthetic compounds by plant extracts," said Jungbauer.