That sneaky, sweet substance in many people's favourite treats can be downright dirty when it comes to playing with the heart and liver. Unfortunately, Britons love the stuff and consume, on average, 238 teaspoons of the substance each week, more than three times the average from 50 years ago. Now that's a lot of sugar.
Broken down, table sugar is essentially composed of molecules of fructose and glucose. When too much fructose finds its way into the human body, it doesn't break down and metabolise like other carbohydrates. Robert Lustig, professor of pediatric endocrinology at University of California, explained that what the body does instead is "turn excess fructose into liver fat. That starts a cascade of insulin resistance (insulin promotes sugar uptake from blood) which leads to chronic metabolic disease, including diabetes and heart disease."
Researchers at The University of Texas Health Science Center at Houston (UTHealth) recently published a study in the Journal of the American Heart Association which showed a correlation between eating too much sugar and heart failure. The reason for this is a small molecule called glucose 6-phosphate (G6P). When too much of this sugar molecule accumulates, it causes changes to muscle proteins and also induces poor pump function, which can ultimately lead to heart failure.
Another study published in the American Journal of Clinical Nutrition illustrated that fructose can rapidly cause liver damage even if no weight is gained. During the study, researchers at the Wake Forest Baptist Medical Center tested animals who were fed a diet high in fructose to measure biomarkers of liver damage. The control group was fed a diet of complex carbohydrates and soy protein.
"What surprised us the most was how quickly the liver was affected and how extensive the damage was, especially without weight gain as a factor," said Kylie Kavanagh, D.V.M., assistant professor of pathology-comparative medicine at Wake Forest Baptist and lead author of the study. "Six weeks in monkeys is roughly equivalent to three months in humans."
Results indicated that, in the high-fructose group, intestinal bacteria was migrating to the liver more rapidly than the control group and causing damage. This was apparently due to the fact that fructose was causing the intestines to be less protective than normal and allowing bacteria to leak out a fairly high rate.
Laura Thomas, founder of happysugarhabits.com, commented, "Changing one's sugar habits is truly about making a conscious choice to be healthier and live longer, and it seems like science is continually proving that point as it delves further into the chemistry and effects of sugar."