Tailor yogurt for diabetes and hypertension management.

Type 2 diabetes is a growing health concern. Statistical data indicate that the total prevalence of diabetes in the United States is 20.8 million, which is about 7% of the total population. In 1980 and 2003, this was 5.8 million and 13.8 million, respectively. Type 2 diabetes and cardiovascular diseases are largely diet-linked diseases. We need cost-effective, simple dietary solutions as the first and major line of defense--with diet-based prevention as the focus.

Scientists at the University of Massachusetts investigated the anti-diabetic and anti-hypertension potential of plain and fruit-enriched yogurts. Their efforts show that dairy or soy yogurt enriched with fruit phytochemicals has potential use in Type 2 diabetes and hypertension management.

The investigators began by screening select brands of dairy and soy yogurt enriched with strawberries, blueberries and peaches. They wanted to determine total phenolic content, antioxidant activity, the enzymes relevant to the in vitro inhibition of type 2 diabetes, such as alpha-glucosidase and pancreatic alpha-amylase, and the inhibitory activity of hypertension-relevant angiotensin-converting enzyme (ACE-I).

Researchers found that the blueberry yogurt had the highest phenolic content of all selected brands. Blueberry yogurt also had the highest DPPH scavenging activity and alpha-glucosidase inhibition potential, which correlated to phenolic content. Alpha-amylase inhibitory activity was not correlated to any specific types of yogurt, whether they were plain, soy-based or fruit-enriched.

The variation in inhibitory activity in the highest range was from 48% to 69% in certain brands that were plain, soy-based or fruit-enriched. Regarding ACE-I inhibition, the highest activity was correlated to soy-based and fruit-enriched yogurts. DPPH radical scavenging and alpha-glucosidase inhibitory activity may be correlated to total phenolic content, whereas alpha-amylase and ACE-I inhibition may not. All soy yogurts and select fruit enriched dairy yogurts had high ACE-I inhibitory activity.

The work is continuing. These were preliminary in vitro studies that helped the researchers to focus studies toward rat and human models. From these initial studies, the scientists found that soy and blueberry base in yogurt has the best enzyme inhibition potential.

One challenge in commercial yogurts is the high levels of added sugar. This has to be considered with overall sugar intake per day so that it is targeted to the right person with the right need. The researchers also are developing soy-based fruit synergies with live probiotic bacteria and lactic acid bacteria and with low added sugar as a liquid-based buttermilk formulation. This could be taken as an acid drink with different flavors, or it could be added to soups or salad dressings, to fit an appropriate food culture or choice.

Further information. Kalidas Shetty, Department of Food Science, University of Massachusetts-Amherst, 340 Chenoweth Laboratory, 100 Holdsworth Way, Amherst, MA 01003; phone: [phone]; fax: [phone]; email: [e-mail].