More than one-third of American adults are now classified as obese, meaning they have a body mass index of greater than 30—and putting them at increased risk for numerous health problems, including stroke, many types of cancer, and osteoarthritis. Obesity is also a key risk factor for type 2 diabetes, which in turn can lead to vision loss, kidney disease, and heart disease.
What is driving the increase? According to a panel of experts who gathered Sept. 13 at UC Berkeley to discuss the issue, there is growing evidence that sugar—specifically the sugar that’s added to packaged and processed foods and beverages—may be a significant culprit in our deteriorating health. This is true not just in the U.S., they suggested, but around the globe, where rates of both obesity and diabetes are mirroring the increases we’re seeing here.
Sugar and sickness
According to speaker Gary Taubes, author of “The Case Against Sugar” and co-founder of the Nutrition Science Initiative, where he serves as Senior Scientific Advisor, there is “powerful circumstantial evidence” that added sugar is in fact making us sick. In fact, he stated that “sugar is the prime suspect on a worldwide level” when it comes to increased rates of diabetes and obesity. Taubes was joined in his assertion that sugar consumption is dangerous to our health by other nutrition and medical experts, including Ronald Krauss, MD, Senior Scientist and Director of Atherosclerosis Research at Children’s Hospital of Oakland Research Institute (CHORI); Janet King, PhD, Executive Director at CHORI and UC Davis Department of Nutrition faculty member; and Kristine Madsen, MD, Associate Professor at UCB School of Public Health.
These experts have been exploring the fundamental question of which environmental and dietary triggers may be causing the obesity epidemic and related diseases. Dr. Krauss, whose interest lies in heart disease, noted that there is compelling evidence linking the consumption of added sugar to heart disease. There are physiological reasons for this connection, said Dr. Krauss. For one thing, the fructose in refined sugar and high fructose corn syrup targets the liver in a specific way that leads to fatty liver disease and metabolic syndrome—a cluster of cardiometabolic risk factors linked to heart disease. Note that this doesn’t apply to the naturally occurring fructose in fruit, which is not considered an added sugar.
Taubes asserted that sugar has a unique influence on health beyond the calories it contributes to the diet, stating that our previous understanding of a “calorie equaling a calorie” is “incomprehensibly naïve” when it comes to understanding the role of what we eat and obesity. According to Taubes, “different foods have fundamentally different effects on the body,” including the different hormones that tell our body to store and process fat. Dr. King further noted that foods high in sugar take the place of healthier foods, and that individuals with high-sugar diets tend to consume less of the recommended intakes for vitamins, minerals, protein, and other important nutrients compared with those whose diets contain less added sugar.
Curbing our consumption of added sugars
The experts pointed to two factors needed to decrease the amount of added sugar being consumed in the U.S. and abroad: increased knowledge and public health initiatives. The panel agreed that upcoming changes to nutrition labels showing the amount of added sugar in a serving will provide some help, though it will be important for public health officials to help the public understand what those labels actually mean. (Companies have until 2020 to implement the new labels, pushed back from the original deadline of 2018.) Dr. Madsen noted that taxes on sugar-sweetened beverages (also known as soda taxes) have been successful at reducing soda consumption in some areas where they’ve been implemented, including Berkeley. The effect appears to be particularly strong in low-income communities. A tax on soda, Dr. Madsen said, may be one way of competing against the profit-driven motives of the soft drink industry—which spends billions of dollars every year on advertising and marketing. Soda taxes, she added, are one of the few public health interventions that actually raise money instead of costing money.
The panel recognized that changing our national focus to the health effects of added sugar may be difficult. To the public, nutrition advice often seems to swing like a pendulum, and consumers may mistrust a focus on a “new” dietary villain after decades of hearing mainly about the evils of fat. The panel also pointed to a lack of understanding among the public about what constitutes “good science,” making it easy for industry to exert influence on public opinion. Public health officials and health workers can play a key role in helping communicate nutrition advice and health recommendations to the public, they concluded.