Sugar (in the form of added sugar, like table sugar/ glucose) is generally considered to be a slow poison, specially if it is consumed in excessive amounts. However, it seems that fructose might be more harmful than normal table sugar or sucrose/ glucose.
A new study has shown that fructose has drastic effects on the reproductive systems and lifespans of female mice, as opposed to the table sugar. Sugar exists in several types, with chemical differences distinguishing them from each other, which might be accounting for their different effects. The experiment involved feeding female mice with the equivalent of human doses of fructose. They were then demonstrated to have their reproductive abilities reduced. Furthermore, their lifespans also decreased.
The mice were divided into two groups: one was fed with high proportion of fructose compared to glucose, and the second one was fed with table sugar. The proportions were determined by finding the equivalent of the sugar consumption by humans. The mice were then followed for 40 weeks. Their lifespan, offspring, and the competition existing between the individuals were observed and evaluated.
The results showed that females consuming lots of fructose had 1.87 times higher death rates than their counterparts feeding on sucrose-based diets. The former also had 26.4 % fewer offspring, indicating that their reproductivity might have been adversely affected as well.
However, this difference in effects were not observed in male mice. This was interpreted to mean that both sugars – fructose and table sugar – are toxic to male mice to the same extent. Previous studies had already shown that sugar has negative repercussions on the male mice.
The lead researcher himself, scientist Wayne Potts, was surprised at the marked difference between fructose and table sugar.
“This is the most robust study showing there is a difference between high-fructose corn syrup and table sugar at human-relevant doses,” said biologist Wayne Potts.
Why the discrepancy between the two sugars? Scientists have not yet confirmed the cause of difference. The chemical nature and the way they are broken down might play a role. Perhaps, at the level of the gut where food consumed interacts with the microbiota present in the alimentary canal to ease digestion, certain reactions are occurring that lead to the mentioned impacts. One type of sugar might be favouring the propagation of bacteria more than usual and hence causing the disruptions in the system of the mice.
The relevance of these results to our context relates to how fructose is widely used in our food preparation. Corn syrup which contains great levels of fructose is found in many processed foods like soft drinks. It is to be borne in mind that fructose and table sugar are chemically distinct. Corn syrup, for instance, has more fructose than glucose, and thus, the two sugars exist as separate molecules. However, in the white powdered table sugar we usually use, fructose and glucose are in more or less the same proportion such that they exist as bonded molecules.
According to past surveys, Americans have shifted from using sucrose as their main added sugar, to corn syrup that contains great amounts of fructose. The lead author, Potts, pointed out that this change in sugar-type consumption coincided with the time when non-communicable diseases like diabetes and obesity began developing into epidemics. Both the shift from sucrose to fructose and the general increased consumption of added sugar are said to account for the drastic increase in the occurrence of these diseases.
Therefore, the consumption of high quantities of fructose by humans is problematic if the fructose is indeed responsible for the negative changes in one’s body system.