Now that even China has joined the worldwide diabetes epidemic, it’s crucial that we all truly understand how we could prevent this very preventable disease — at least for type 2 diabetes, which is the adult-onset diabetes mostly related to obesity and the “Western” lifestyle.

The key concept for diabetics is limiting carbohydrates — and that doesn’t only mean sugar. I see many diabetics who think they’re doing well because they’re “cutting back on sweets and dessert”, when the main diabetic culprit in their diet is the starch carbs from rice, pastas and breads.

One popular method of monitoring carbs is the glycemic index. This index is a ranking from 0-100 of how high a carbohydrate raises blood sugar levels after eating. Here’s a graph below showing the basic concept: a healthy food has a low glycemic index, which means the sugar levels in your body peak lower and slower, thus not stressing out your insulin-secreting pancreas. Unhealthy foods have a high glycemic index, where the sugar levels peak very high and very quickly. This stresses out your pancreas to make insulin, and it’s this chronic repeated stress of your pancreas that partly causes it to slowly fail, producing less insulin — and thus causing diabetes.

Think Brown

Following this GI list of foods, and tracking your foods, can honestly be quite cumbersome. Many believe that patients’ counting their carbs is a more effective tool. But in either case, I have an easy clue for everyone: think brown. Brown food is always better than the equivalent white food. What do I mean? I mean that white foods are quite unnatural; white rice and breads and pastas are finely processed versions of the original grains. And these original grains have the “brown” husks full of vitamins, oils, magnesium, fibers and other nutrients. In other words, brown rice is much healthier than white rice for many more reasons than just lowering risk of diabetes. The glycemic index of brown rice is 55, a bit lower than the 72 for short-grain white rice, which is the most common rice in China. Here’s more data which may convince you: a huge 2010 cohort study showed that switching from white to brown rice can lower your risk of diabetes by 16%. Switching to whole grains lowered risk even better, by 36%. That’s an enormous benefit!

Bread & Pastas: The Same Benefit

The same concept applies to white bread, which is made of finely processed flour and thus has lost its husk of nutrients and fiber. The GI of white bread is 70 (a GI over 70 is considered unhealthy), while whole grain breads have a GI of 51. Pasta, on the other hand, has a much better glycemic index than breads or rices, with a GI range from 43 to 61.