I came across this paper investigating the effect of a high vs low GL (glycaemic load) diet on IGF-1 levels.
The researchers used a crossover design (i.e., the same subjects experienced both diets) in 84 overweight-obese and normal weight healthy individuals using two 28-day weight-maintaining high- and low-GL diets (both were 15% energy from protein, 30% energy from fat and 55% energy from carbohydrate, but differed in GL, one being ≥ 250 and the other ≤ 125). They measured both fasting and post-prandial concentrations of insulin, glucose, IGF-1 and IGFBP-3.
Low-GL diet resulted in a 43% lower glucose and 27% lower insulin response after a meal, and while fasting serum glucose concentrations were similar between diet treatments in the lean group, this was not the case in the overweight/obese group: mean fasting glucose was 0.12 mmol/L higher following the low- compared to the high-GL diet. The low-GL diet led to 4% lower fasting concentrations of IGF-1 (10.6 ng/mL, p = 0.04) and a 4% lower ratio of IGF-1/IGFBP-3 (0.24, p = 0.01) compared to the high-GL diet.
This study, therefore, suggests that lowering refined carbs can not only improve glucose metabolism but also have some effect on IGF-1 so helping to reduce cancer risks.
The researchers used a crossover design (i.e., the same subjects experienced both diets) in 84 overweight-obese and normal weight healthy individuals using two 28-day weight-maintaining high- and low-GL diets (both were 15% energy from protein, 30% energy from fat and 55% energy from carbohydrate, but differed in GL, one being ≥ 250 and the other ≤ 125). They measured both fasting and post-prandial concentrations of insulin, glucose, IGF-1 and IGFBP-3.
Low-GL diet resulted in a 43% lower glucose and 27% lower insulin response after a meal, and while fasting serum glucose concentrations were similar between diet treatments in the lean group, this was not the case in the overweight/obese group: mean fasting glucose was 0.12 mmol/L higher following the low- compared to the high-GL diet. The low-GL diet led to 4% lower fasting concentrations of IGF-1 (10.6 ng/mL, p = 0.04) and a 4% lower ratio of IGF-1/IGFBP-3 (0.24, p = 0.01) compared to the high-GL diet.
This study, therefore, suggests that lowering refined carbs can not only improve glucose metabolism but also have some effect on IGF-1 so helping to reduce cancer risks.