Hemp protein reduces blood glucose and insulin after a meal Original paper

Although acute studies suggest that whey and soy protein reduce the blood glucose response to a carbohydrate meal,^[1][2] little research has looked at hemp protein in this context.

This study assessed the effect of hemp protein on blood glucose, insulin, and satiety compared to soy protein and a carbohydrate control. In two separate randomized crossover trials, 43 participants (27 in trial I, 16 in trial II) consumed calorie-matched smoothies containing 40 grams of hemp protein, 20 grams of hemp protein, 40 grams of soy protein, 20 grams of soy protein, or a fruit smoothie without added protein (the carbohydrate control). Sixty minutes after the smoothie treatment, the participants consumed a pizza meal.

In trial I, the pizza meal was provided without restriction, and the authors recorded the participants’ calorie intakes. In trial II, the participants were given a fixed quantity of pizza. In both trials, the investigators assessed blood glucose and subjective appetite at various time points from smoothie ingestion until 140 minutes after pizza ingestion (200 minutes after smoothie ingestion), and in trial II, they also assessed insulin.

In trial I, both 40-gram protein treatments (soy and hemp) led to lower cumulative (up to 200 minutes) blood glucose than the 20-gram protein treatments and the control. The 20-gram protein treatments also decreased blood glucose compared to the control. The 40-gram hemp protein condition increased appetite compared to the 20-gram soy protein condition.

In trial II, blood glucose in the 40-gram treatment groups was lower than in the 20-gram and control treatment groups, and the 20-gram treatments lowered blood glucose compared to the control. The 40-gram soy protein treatment significantly reduced insulin compared to the control. Although the other treatments tended to reduce insulin in a dose-dependent manner, the differences were not significant. None of the conditions had an effect on appetite.

The authors concluded that hemp protein, like soy protein, lowers postprandial (postmeal) blood glucose and insulin concentrations in a dose-dependent manner compared to a carbohydrate control. However, the protein content of the drinks was inversely associated with carbohydrate content, so the decreased glucose response may have been partially due to the reduced carbohydrate concentration in the high-protein drinks.

Although the authors assessed multiple outcomes, they did not make statistical adjustments for multiple comparisons, increasing the likelihood of obtaining a false positive.