Those of us who have diabetes have something to smile about when we learn that a tasty food we love to eat but we thought was bad for us is actually good. As I ate my blueberries this week I experienced those smiles.
Nobody likes blueberries more than I do. But the few times I have eaten them lately have been guilty pleasures. That’s because blueberries are high in carbohydrates, which can wreck havoc with our blood glucose control.
Blueberries seemed to decrease inflammation when researchers tested them in animals. In spite of their carb content animals appeared to have lower BG levels when they ate their berries.
But until now we didn’t know much about what blueberries would do for people. So Drs. William Cefalu and associates set out to study what blueberries might do for us. They work at the Pennington Biomedical Research Center, a part of the Louisiana State University System.
They didn’t study people with diabetes. Instead, for six weeks they studied 32 obese people who have prediabetes, or insulin resistance.
So, is this work relevant to those of us who have gone all the way into diabetes? I think so, because the difference between prediabetes and diabetes comes down to whether we have burned out lots of the beta cells in our pancreas or not. Like us, people with prediabetes already have a lot of insulin resistance that can eventually burn out the beta cells.
This study meets the highest standards of clinical trials -- it is a double-blind, randomized, and placebo-controled clinical study design. The Journal of Nutrition will publish their findings in its October 2010 issue. Meanwhile, however, the journal has already published the study, “Bioactives in Blueberries Improve Insulin Sensitivity in Obese, Insulin-Resistant Men and Women,” online. While only the abstract is free online, I got the full-text through my subscription.
The people in the study who ate the blueberries had significantly improved insulin sensitivity compared to those in the control group who weren’t so lucky. Changes in body fat, calorie intake, or inflammation were not at work here.
Researchers guess that the health benefits of blueberries might come from their phenolic bioactive compounds like anthocyanins, which are also anti-oxidant. They are red, purple, or like blueberries in particular, blue. Dark blue.
The people in the study got their blueberries from frozen powder in a smoothie. The control group got their smoothies without the blueberries but with the same taste and calories.
Not increasing our calories -- and the amount of carbs we eat -- is also our challenge when we add blueberries to our diet. After all, one cup of them has 12 grams of carbs, the maximum amount those of us who eat low-carb will want to have in any meal.
When we add blueberries to what we eat, we can remove something else. This way we can keep smiles on our faces as we consume a delicious and healthy food.