Wednesday, February 01, 2012

Whole Grains And Diabetes

I was scanning studies this morning, as is my wont, and stumbled upon:

Cereal Grains, Legumes And Diabetes, European Journal Of Clinical Nutrition, 2004
"This review examines the evidence for the role of whole grain foods and legumes in the aetiology and management of diabetes.

Epidemiological studies strongly support the suggestion that high intakes of whole grain foods protect against the development of type II diabetes mellitus (T2DM). People who consume approximately 3 servings per day of whole grain foods are less likely to develop T2DM than low consumers (< 3 servings per week) with a risk reduction in the order of 20–30%.

This is consistent with the results of dietary intervention studies that have found improvements in glycaemic control after increasing the dietary intake of whole grain foods, legumes, vegetables and fruit. The benefit has been attributed to an increase in soluble fibre intake. However, prospective studies have found that soluble fibre intake is not associated with a lower incidence of T2DM. On the contrary, it is cereal fibre that is largely insoluble that is associated with a reduced risk of developing T2DM. Despite this, the addition of wheat bran to the diets of diabetic people has not improved indicators of glycaemic control. These apparently contradictory findings might be explained by metabolic studies that have indicated improvement in glucose handling is associated with the intact structure of food. For both grains and legumes, fine grinding disrupts cell structures and renders starch more readily accessible for digestion. The extent to which the intact structure of grains and legumes or the composition of foods in terms of dietary fibre and other constituents contribute to the beneficial effect remains to be quantified.
I thought this was a fairly comprehensive and well-referenced article on diets, whole grains, and diabetes. I'm still scouring it. Here are two more bits I found informative, about insulin resistance:
"High intakes of fat, especially saturated fatty acids may increase resistance to the action of insulin, the underlying abnormality in many cases of T2DM."

"Considering the scope of these dietary intervention studies, there is little doubt that diets containing substantial intakes of whole grain foods, fruit, vegetables and legumes are associated with an improvement in insulin sensitivity and other indicators of carbohydrate metabolism including improved glycaemic control in people with diabetes."
They really drive home the point that grain should be in the unrefined, whole state.
That's a photo of my brown basmati rice, rinsed, waiting for the water to boil before I drop it in.


Laurie Endicott Thomas said...

Grains are high in carbs but low in fat. We've known for about a hundred years that low-fat, high-carb diets improve insulin sensitivity. Why do people express such surprise every time this obvious fact is "discovered"?

preserve said...

Laurie: This post is not "obvious".

1) I was not aware that red-vines candy, low in fat and high in carbs would improve insulin sensitivity.

2) The benefits of fiber is also not obvious. There are many people out there that think they are eating healthy simply because they are eating processed fiber.

Anonymous said...

I would think the benefit from eating whole grains is due to the "health halo"... the participants who ate whole grains vs. white are probably more health conscious, probably exercise more, probably are at a healthier weight, etc, etc... so this does not prove whole grains are good for us.

Bix said...

I think you make a great point in that you can never fully account for the placebo effect. (I use the word placebo here not as a null therapy but as a positive therapy - with the expectation for healing, as opposed to nocebo, a negative therapy, with the expectation for dis-ease.)

People who eat whole grains with the belief that whole grains are good for them have a placebo operating, in addition to (or perhaps synergistic with?) any effect from the food itself.

As to the food itself, why wouldn't an intact grain, sprouted even, provide more nutrition than, say, Wonder Bread?

Dr. Mel said...

@Anonymous--So you're saying it's not simply what you *eat* but the way you conduct your life? Exercise and so forth?

Anonymous said...

Saturated fat increasing resistance to insulin is a good thing if you are on a low-carbohydrate <20% protein diet (which is, BTW, the best diet for longevity).