Dietary Insulin And Colon Cancer

The Study

In this investigation, Harvard researchers created a dietary scoring system of foods that promote a high insulin response. They called it the Empirical Dietary Index for Hyperinsulinemia (EDIH). This is different than the glycemic index, which focuses on the blood sugar effects of carbohydrate containing foods. This index includes all foods that spike insulin after consumption. 

The food groups that contributed to a high EDIH score include red meat, low energy soda, cream soups, processed meats, margarine, poultry, French fries, fish, sugar sweetened beverages, tomatoes, low fat dairy and eggs.

The food groups that contributed to a low EDIH score included wine, coffee, fruit, high fat dairy products and green leafy vegetables.

Over 120,000 men and women from the Nurses’ Health Study and the Health Professional Follow-up Study had an EDIH score calculated for their diet and were followed for 26 years. Subjects with the greatest EDIH score had a statistically significant 26% higher risk of colon cancer when compared to subjects with the lowest EDIH score. American Journal of Clinical Nutrition 2018; 108:363-70.

Take Home Message

When choosing a diet to promote weight loss, you always want to look at the long-term health effects of the diet as well.   

The EDIH score takes the idea of the glycemic index a step further. The GI focuses on the blood sugar effects of carbohydrate foods. The EDIH score includes any food that increases insulin. A lot of these foods are proteins. Many popular current diets are really high in animal protein, and this study makes you think twice about them. 

As far as mechanisms go, it is thought that very high levels of insulin, and insulin derived growth hormone may be carcinogenic. 

In addition to keeping your glycemic index low, it is a good idea to go easy on the animal proteins. It is particularly important to limit red meat and processed meats. It is also a good idea to substitute vegetable proteins such as beans, nuts, whole grains and legumes for animal proteins whenever possible.