Adding Sugar Makes High-Fat Diet Worse

New research that sheds light on the effects of adding fructose to a high-fat, Western diet shows that a regimen high in sugar and fat may be worse than a high-fat diet alone.

University of Naples researchers showed that short-term consumption of a Western diet rich in saturated fats and fructose is more damaging for healthy liver development than following a diet that’s strictly high in fat, finding that a high fructose, high-fat diet had a harmful impact on adult rats’ livers.
_______________________________________________________________________________________________________________________________________________________

RELATED CONTENT
Saturated Fats May Not Be As Bad As We Thought
Saturated Fat Is Your Friend, Not Foe
_______________________________________________________________________________________________________________________________________________________

The authors performed the research by using an animal model of adult sedentary humans, consisting of adult rats. The rats were fed for 2 weeks with either a low-fat diet, a high-fat diet, or a diet rich in fat and fructose, according to the researchers, who note that the latter diet is very similar in composition to the diet consumed by the majority of the Western population. After the diet period, the authors evaluated liver function, finding that the presence of fructose in the high-fat diet exacerbated the impairment of the liver, by increasing the build-up of fat, and decreasing liver insulin sensitivity.

“Our present findings point to the harmful effect of adopting dietary habits that include packaged foods,” says Susanna Iossa, PhD, a professor in the department of biology at the University of Naples, and lead author of the study, “usually containing high amounts of fructose.”

While noting that more research should be done in the future—especially with regard to the impact of the high-fat, high-fructose diet on other metabolically critical organs—to determine the true impact of a high-sugar, high-fat diet on overall health and well-being, Iossa and the authors say the findings should spur discussion about the use of fructose and fructose-containing sweeteners in beverages and packaged foods.

—Mark McGraw

Reference

Crescenzo R, Bianco F, et al. Fructose supplementation worsens the deleterious effects of short term high fat feeding on hepatic steatosis and lipid metabolism in adult rats. Experimental Physiology. 2014.