Nutritionists are concerned with what you put in your mouth. What happens to it after you swallow is outside their jurisdiction. Sure, whole grains contain substances that may prevent cancer, so nutritionists tell you to eat them. However, all the carbohydrates that come packaged with those nutrients, by raising insulin levels, will compromise your ability to absorb those nutrients.

It's a similar story, for instance, with orange juice. Orange juice contains vitamin C, so nutritionists tell you to drink orange juice. But orange juice contains a lot more glucose than vitamin C. Glucose and vitamin C have a similar chemical structure, so they use the same receptors at the cellular level. If there's a lot of glucose in your blood, those receptors will never get around to the vitamin C. So the vitamin C in orange juice is pretty much useless; it never gets absorbed. That doesn't stop nutritionists from telling us that orange juice is healthy because it contains vitamin C.

The beneficial nutrients in whole grains are available in plenty of other foods with fewer carbohydrates. There's no need for whole grains and no appreciable health benefits to eating them. To say that whole grains are better than refined grains is akin to saying that filtered cigarettes are healthier than non-filtered cigarettes.