Is One Ingredient to Blame?

I’m a nutrition consultant for various food and beverage companies, but my opinions are my own.

“Sugar is Toxic.”

“The Case Against Sugar.”

“How to Ditch the Sugar Habit.”

“Is Sugar Destroying the World?”

Perhaps you have seen some of these headlines over the past couple of years. As researchers in the medical field continue to search for the cause of obesity and its associated diseases, sugar is the scapegoat of the moment. Starting in the 1970s it was all about fat, which led to a plethora of low-fat products lining supermarket shelves; however, obesity rates continued to rise and the onus of blame shifted to added sugars like sucrose (table sugar) and high fructose corn syrup.

But is it really fair to say that increased rates of obesity, type 2 diabetes, and cardiovascular disease are caused by one ingredient? 

Dr. John L. Sievenpiper of St. Michael’s Hospital, University of Toronto doesn’t think so. In a new textbook, Fructose, High Fructose Corn Syrup, Sucrose and Health (Springer Publishers March 6, 2014), edited by James Rippe, MD, Dr. Sievenpiper shares his thoughts. “We have to be careful of this one nutrient approach to things, because we don’t consume in a vacuum.” Recognizing that removing one nutrient or ingredient from the diet is only part of the equation – what that nutrient is replaced with is just as important – Dr. Sievenpiper emphasizes that  “Healthy eating in general is what we need to talk about. Sugar is only a problem in so far as it contributes to excess calories, but no more so than other highly palatable foods that can be over consumed and provide excess calories without a lot of nutrients. If you keep the total calories the same but replace the sugars with refined starch, you’re not going to do any better.”

Dr. Sievenpiper has spent years using the gold standard of research – randomized controlled trials – to investigate diet and disease relationships, with a focus on the metabolic effects of sweeteners and diabetes. When it comes to sweeteners and health outcomes, observational and population-based studies are more common than clinical trials. While these studies often have the advantage of long follow-up periods and the ability to determine the incidence of disease, they are limited in design. Arguably their most important limitation is that in the end they don’t really tell us why we see the relationship we do – they only show association, not causation.

So why not do more randomized controlled trials? Dr. Sievenpiper says that cost is the main reason. “Randomized controlled trials are very expensive. The cost to do the same trial on humans as on animals would be an order of magnitude of difference.” For example, a 10-year trial looking at hard outcomes like diabetes and cardiovascular disease in over 100,000 participants would likely cost approximately $300 million. As a result, we see more ecological, observational, and cohort studies completed, with findings given more weight than they deserve. The media often sensationalizes these findings despite their significant limitations.

So what will resolve the obesity and diabetes crisis? The World Health Organization recently reinforced their 2003 recommendation of no more than 10% of daily calories from added sugar, and they made headlines by setting a conditional recommendation of no more than 5% of daily calories from added sugar based on evidence relating to dental caries that the researchers themselves reported was “very low-quality.” The jury is still out on the 2015 Dietary Guidelines for Americans recommendations for added sugar, but Dr. Sievenpiper doesn’t believe any of the science points to a change in the current recommendations.

And then there’s the topic of regulation, which some people think is the answer. Dr. Sievenpiper doesn’t agree: “We need to go back to dietary patterns – what’s a healthy diet and how do we achieve it. What good things are available and what swaps can we make? How do we build healthy dietary patterns without forsaking exercise? We need to teach life skills and then create an environment where people can exercise them. Rather than regulating serving sizes and taxing specific foods, I’d rather see regulations relating to home economics in school – from an early age we should be teaching all kids about food – how to read food labels, how to prepare food – so they can be independent and informed thinkers. More physical activity mandated in schools – at least one hour a day every day. Not just team sports, but activities kids can learn for life like walking and hiking. We need cultural changes in terms of our approach to food and physical activity. It’s not relying on any one thing. We need a radical shift in the way we think. The biggest enemy to success is this one nutrient approach.”

What do you think is the answer to obesity?