A lot of you probably keep up with the latest health news, especially as it relates to diabetes. Late last year, one of the newsworthy items had to do with soy yogurt and diabetes. Not exactly a topic of great excitement, you might be thinking, but this story has generated sparks of interest, especially in the blogging community.
In a study published in the December 2006 issue of the Journal of Food Biochemistry, researchers at the University of Massachusetts, Amherst, examined different kinds of yogurt—plain and fruited, including soy yogurt—for compounds that might help control diabetes.
There are certain diabetes medicines, called alpha-glucosidase inhibitors, that target enzymes in the digestive tract. These enzymes, alpha-amylase and alpha-glucosidase, are involved in carbohydrate digestion. Blocking the action of these enzymes helps slow the digestion of carbohydrate, thus slowing the typical rise in blood glucose after eating a meal. The researchers in the yogurt study tested the different types of yogurt to see if they had any effect on these enzymes.
The researchers were also interested in how the various types of yogurt affected another enzyme, called angiotensin-I converting enzyme (ACE-I), which might sound familiar to you if you happen to take an ACE inhibitor for your blood pressure or kidney health. ACE-I can cause blood vessels to narrow, thereby raising blood pressure.
Plant compounds can block all three of these enzymes, opening the door for the use of more natural therapies. Of course, drugs are effective, but as we all know, drug therapy can sometimes have unpleasant and even harmful side effects.
Samples of peach, blueberry, strawberry, and plain yogurts (all different brands, including a soy brand) were tested for their ability to block these three enzymes. Interestingly, the blueberry soy yogurt packed the most punch by blocking all three enzymes. The peach and strawberry yogurts did a pretty good job, too, and even the plain soy yogurt fared well.
It’s known that fruit and soy products contain natural compounds called phenols. Phenols are known to boost heart health and are found in tea, red wine, and dark chocolate, among other foods. In this experiment, the yogurts with the highest phenol content—the plain soy yogurt and the blueberry dairy yogurts—were the best at blocking the enzyme alpha-glucosidase. The soy yogurts were also the best at inhibiting ACE-I.
While this experiment didn’t involve human subjects, it did add to the arsenal of evidence that diets rich in fruits and vegetables (and soy) may help protect against certain diseases.
But don’t stop taking your diabetes or blood pressure medicines just yet. What isn’t known is how much blueberry yogurt, for example, a person would have to eat to see an improvement in blood glucose or blood pressure readings. And while you might already be eating yogurt for a snack or as part of a meal, you still need to consider the carbohydrate content. On average, a six-ounce serving of a fruited soy yogurt contains about 30 grams of carbohydrate (the amount found in two slices of bread or in a medium-sized banana), along with 160 calories and 2 grams of fat. The nutrition content of many fruited dairy yogurts is similar.
So, despite its potential benefits, yogurt isn’t a “free” food. Go ahead and enjoy yogurt and soy yogurt, but remember to count those carbohydrates. More on dairy and diabetes next week.