Is fructose all to blame for obesity?

What was the pivotal moment for the ban on trans fats? It was tough convincing the scientific community and certainly the industry that trans fats were especially harmful. This is because of the dogma that margarine and Crisco oils were somehow better for you than were lard and butter. The evidence kept coming in from epidemiological studies showing that people who ate more trans fats had increased levels of LDL and decreased levels of HDL, and the dogma that saturated fat was the villain in heart disease was reinforced. Maybe that pivotal moment was when a researcher with experience testing trans fat deposition in cadavers and pigs sued the US Food and Drug Administration (FDA) for not acting on cumulative evidence sooner.

Do we have this kind of evidence to make a claim for the FDA to ban HFCS? What we have is the time course of HFCS entry into the food supply which occurred in 1970. This coincided with the growing prevalence of obesity between 1960 and 2000.

The excess energy in SSBs can provide a hedonic stimulus that overcomes the natural energy balance regulatory mechanism because SSBs excess energy comes in liquid form and may bypass the satiety signal in the hypothalamus.

We still have to prove this.

Blaming fructose in HFCS as the sole cause for the increase obesity will be much tougher than blaming trans fats for an increase in LDL cholesterol and a decrease in HDL cholesterol.

The prevalence of obesity has increased worldwide, even in countries where SSBs do not contain HFCS.

Still, the proof that HFCS can override the satiety pathway and cause excess calorie intake is intriguing and may have teeth if we can pinpoint the increase in prevalence of obesity in children and adolescents on increased ingestion of HFCS in SSBs. There is no reason nutritionally to add sugar or HFCS to liquids. Plus, if HFCS has a metabolic disadvantage then all the more reason to ban it. Then, it becomes like trans fats: a toxin in the food supply.

Dr. Apovian is a Faculty Member, Department of Medicine; Co-Director, Center for Weight Management and Wellness, Section of Endocrinology, Diabetes, and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts. She has disclosed financial relationships with Altimmune, Inc; Cowen and Company, LLC; Currax Pharmaceuticals, LLC; EPG Communication Holdings, Ltd; Gelesis, Srl; L-Nutra, Inc; NeuroBo Pharmaceuticals; and Novo Nordisk, Inc. She has received research grants from the National Institutes of Health; Patient-Centered Outcomes Research Institute; GI Dynamics, Inc.

A version of this article appeared on Medscape.com.