This study, available in full text for free, makes some very interesting reading.
It compares the end results of two diets of identical macronutrient ratios, but differing sucrose contents, on insulin sensitivity. The subjects were moderately insulin resistant, slightly heavy volunteers. Result: Obtaining 25% of your calories from sucrose, compared to 10%, has absolutely no adverse effect on your insulin sensitivity. That's s relief to any sugar dependent young white male on the verge of type 2 diabetes. Or any researcher who's funding comes from here:
" This study was supported by an unrestricted research grant from The Sugar Bureau and Suikerstichting, the Netherlands".
But the study is very strange. It only compared the end results of the two diets. Neither diet was the volunteers' habitual diet. There was no formal comparison of the effect of the two new diets on the initial baseline parameters of health in the study participants. Oddly enough some of the changes do get mentioned in the discussion, others don't, on a rather random basis. The excess rise in LDL cholesterol (for anyone who cares) in the 25% sucrose diet compared to the 10% sucrose diet gets attributed to the higher saturated fat content of the high sucrose diet. What sort of dietician fails to control for this variable in a study reporting cholesterol levels? No need to answer that. And why not attribute it to the sucrose?
But you can look at a small number of the baseline data, selected by Dr Black and co, although not all of what was certainly measured.
So if you got to Table 2 of the results, on page 3568, line 8, you can see the fasting plasma glucose was 4.8mmol/l. Normal.
After 6 weeks on the dietician designed diet what was the fasting blood glucose? This never gets a mention anywhere in the paper. But it's there, tucked away in a table in the discussion of all places. Look at Table 7, page 3570, third variable reported.
Ooooooh, it's 5.6mmol/l. Whichever diet you look at.
A fasting plasma glucose of 4.8mmol/l for a carboholic is normal. A value of 5.6mmol/l is prediabetic.
How do you convert a slightly chunky healthy young Irish chap in to a prediabetic?
Easy, get a university nutritionist to design his diet.
Those freeliving chaps were eating 45% of calories as carbohydrate and 35% as fat before the study. Just increase the carbohydrate to 55% of calories and reduce the fat to 33% and voila, prediabetes in 6 weeks. Irrespective of sucrose content.
But don't mention this anywhere in the paper.
Why not? Re check who funded the study.
The purpose of the study was to show sucrose is harmless. It was not designed to look at the effect of carbohydrate in general on fasting blood glucose. It did that by accident.
Sometimes the truth just slips in and no one notices. Or they're not saying.
Enough of this depressing study. A much better one for the next post.