Fiber and Insulin Sensitivity.

Bluddy Americans. It's Fibre! But anyway....

Stabby the Raccoon posted the following study in a comment on CarbSane's blog. I thought that it was so interesting that I am linking to it here.

Fiber and Insulin Sensitivity.

This study has built-in cognitive dissonance.

The first Fig. suggests that cereal fibre is associated with a much lower RR for Type 2 Diabetes Mellitus (T2DM) and that fruit & veggie fibre aren't.

Schulze et al. 2007: Cereal Fiber RR = 0.6 - 0.7. Fruit Fiber RR = 0.9 - 1.05. Vegetable Fiber RR = 0.95 - 1.15 approx.

The next table suggests otherwise.

Andersson et al., 2007: Whole grain diet contained 112 g/d of whole grain, 18 g fiber. No effect of whole grains on insulin sensitivity.

Ebeling et al., 1988: 5 g/d granulated guar. No effect on insulin sensitivity.

Johnston et al., 2010: Resistant starch supplement -40g/d. Improved insulin sensitivity with resistant starch.

Landin et al., 1992: 30 g/d granulated guar, given in 3-10 g doses. Improved insulin sensitivity with guar diet.

Maki et al., 2011: High-resistant starch diet- 30 g/d, Low-resistant starch diet- 15 g/d. Improved insulin sensitivity with both resistant starch diets, but effect only reached statistical significance for men.

Nilsson et al., 2008: White bread enriched with barley fiber and 8g resistant starch, Barley kernel based bread. Improved glucose tolerance with resistant starch.

Pouteau et al., 2010: 28 g/d acetogenic fibers (acacia gum and pectin). No effect on insulin sensitivity.

Robertson et al., 2003: High-resistant starch diet- 60 g/d. Improved insulin sensitivity with resistant starch.

Weickert et al., 2006: Fiber-enriched with 31.2 g insoluble fiber. Improved insulin sensitivity with increased insoluble fiber.

In conclusion, the resistant starches found in high-amylose rices such as Basmati, refrigerated boiled rice & boiled potatoes, also rye & barley breads are beneficial in terms of reducing your RR for T2DM. Watch out, though. Too much dietary resistant starch can cause colic, flatulence & diarrhoea if your intestinal bacteria are knackered. You want fermentation to short-chain fatty acids to occur, not osmotic laxation! See Genetics of Food Intolerance.