The concept of “glycemic index” is often discussed in health circles. Today we answer the question of one of our readers. 

This is what Martha says: 

“When talking about the optimal diet, one of the criteria listed was “low glycemic index”. Again, this comes back to the question of fruit, as many fruits are high on the glycemic index – so again, even though I love fruit I am beginning to wonder to what extent it is wise to consume it on a regular basis.”

ANSWER:

In general, I do not find the glycemic index table useful.

Essentially, to create this index they measured the “average” blood sugar response in “average” people, after eating different types of food.

The key word is “average”.

The average person does not exercise, is overweight, and eats a high fat diet.

So the results of the glycemic index tables will only reflect how the average person reacts to food, not necessarily how a healthy person reacts.

To address the specific concern of your question: Most fruits are not “high” on the glycemic index. Banana is 51 (low), Kiwi is 47 (low), Grapefruit is 25 (low), Mango is 41 (low), Oranges is 31 (low), Papaya is 56 (low). Only watermelon is listed as “high” in most charts (72).

According to Dr. Joel Fuhrman, author of the excellent book “Eat to Live,” “Scientific evidence indicates that the glycemic index of a food is not a reliable predictor of the effect food has on blood glucose levels, cholesterol, and insulin levels.”

You need not be concerned about the glycemic index of a particular food if it is otherwise nutrient and fiber-rich.

The presence of fiber in whole fruits is much more important in blood glucose control than the glycemic index. 

Even high-glycemic carbohydrates such as grains, which I do not recommend anyway, will not cause blood sugar problems or diabetes if they are consumed whole and in the context of a low-fat diet. 

Those high-glycemic foods are linked to glucose intolerance and insulin insensitivity, or insulin resistance (the inability for insulin to properly “carry” sugar to the cells) when consumed with excessive quantities of fat. 

Due the consumption of high-fat foods, there’s a lack of insulin receptors in the cell surface and high levels of insulin are secreted.

When carbohydrates, including sweet fruits, are consumed without fat, and in the context of a low-fat diet, they cause a rather low insulin response.

When someone decides to follow a low-glycemic index diet they may even be causing diabetes if they are eating more high-fat foods that cause the body to secrete more insulin because of insulin resistance.

The glycemic index is also very imprecise because the effect of the same foods on different people can be so different that it would be wrong to consider the glycemic index charts accurate in the first place.

Fruits and vegetables are low to moderate, some being a bit high on the glycemic index, but this doesn’t even matter.

Even high glycemic index foods such as potatoes have no incidence on diabetes and sugar-metabolic disorders in the context of a low-fat diet.

Many cultures have a 0% incidence of diabetes and their diet is composed of 80% high-glycemic foods such as potatoes or rice.

People who write about diet and tell people NOT to eat certain fruits and vegetables because they are supposedly “high-glycemic,” or because of some other issue such as “hybridization” or “natural fructose” are scaring people away from natural foods and instead promote coconut oil and grass-fed beef. It’s sad.

Natural and whole foods are ALWAYS better than refined foods, and it doesn’t matter where they fit on a glycemic chart that some scientists made up using unhealthy people eating a standard western diet as their point of reference.

I never took these faulty charts or theories seriously when I transitioned to raw foods because it’s information we don’t want; and they complicate things when there’s no need. I encourage you to follow the same approach!