Your Glycemic index reminder

By John DiTraglia - Contributing Columnist

We were reminded about this thing called the glycemic index, which is probably really a thing, by the April 8 issue of the New England Journal of Medicine. (1) The glycemic index, which we have belabored before (The glycemic index doesn’t matter, Portsmouth Daily Times 2-2-15), is defined as how much 50 grams of food containing carbohydrates raises the blood glucose level.

It might be thought of as the sugar spikiness of a food. (Spikey vs spiky makes a big list on Google) In general, spikiness is a violation of the proposition that an even keel is better and wide fluctuations are generally found to represent malfunction and/or are damaging to your health. Then there is another thing that this report looked at called the glycemic load of a diet. They calculated this by “multiplying the mean net carbohydrate intake by the glycemic index and then dividing by 100.”

I am not sure what this means exactly but I guess it’s the overall “carbiness” of the food in a diet. You could say that glycemic load includes foods with a high glycemic index and foods without – “carbs lite.” We have also griped about the anti-carb bandwagon numerously in past fat science columns.

The point of the glycemic index and the glycemic load comes from the debate about whether it causes obesity or is otherwise bad for your health.

In this study report, coordinated from the Departments of Nutritional Sciences and Medicine, Temerity Faculty of Medicine, University of Toronto, they looked at a multinational group of 137,851 persons between the ages of 35 and 70 years and analyzed their diets and followed them for an average of 9.5 years to see how much the glycemic spikiness and overall carbiness of diets were associated with death from cardiovascular diagnoses or death overall or nonfatal heart attack, stroke and heart failure.

Bottom line – yes. Diets with a high glycemic index were associated with all those bad things.

Now come the issues:

– This was a multinational project. The point of doing this is because most data about this topic comes from high-income Western populations. In that rich Western world, “although many studies support the consumption of a diet with a low glycemic index in the prevention and treatment of diabetes, data regarding the association between a diet with a low glycemic index and a reduction in cardiovascular risk have been more mixed.”

– In this study, the associations were much stronger in persons with obesity and much weaker among persons with a body mass index of less than 25 which is pretty skinny these days. Insofar as you ascribe to the more-improbable-than-not notion that high carb intensity can cause obesity, and certainly in persons with type 2 diabetes this issue is highly convoluted with obesity. Nobody argues that people with diabetes need to pay a lot of attention to sugar load. However, the people who eat a lot of candy and white bread and stay not obese may not need to be severely sanctioned.

– The results of the analysis with glycemic load/carbs lite were similar but weaker than the results with glycemic index per se.

– Finally, there are the standard heavy provisos that this was an observational study although the proverbially better prospective long term double-blinded controlled study of a low glycemic index diet in non-diabetics is probably going to be impossible to do, and association is not proof of causation.

So sugar is like those other addictive substances, salt and alcohol. Since so many people even in other countries, are pre-diabetic or diabetic/pre-hypertensive or hypertensive/pre-alcoholic or alcoholic that it’s probably beneficial on a population wide basis to eat less sugar/salt/booze. But it’s not as bad as smoking or not wearing your seat belt or jumping out of an airplane without a parachute or not getting a coronavirus vaccine.

1. Jenkins DJA et al. Glycemic index, glycemic load, and cardiovascular disease and mortality. N Engl J Medicine 2021;384:1312-22.

By John DiTraglia

Contributing Columnist

This writer’s opinion is their own and not the opinion of this newspaper

John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- or phone-354-6605

This writer’s opinion is their own and not the opinion of this newspaper

John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- or phone-354-6605