Adolescent fructose consumption: Fructose, obesity, and metabolic syndrome in children

The fact that the title of this column includes the words obesity, metabolic syndrome, and children should alarm us. It is sad they are interrelated. Metabolic syndrome refers to a cluster of conditions such as increased blood pressure, elevated blood sugar levels, excess body fat around the waist, and abnormal cholesterol levels—all of which increase risks for type II diabetes and cardiovascular diseases. These conditions, along with nonalcoholic fatty liver diseases, were once seen primarily in adults, but tragically, now also occur in children. One of the villains perpetuating this reality is excessive sugar consumption.

Fructose in children's diets

Robert Lustig, MD, has long been an outspoken advocate of warning of the dangers of excessive fructose consumption in children. He is a pediatric endocrinologist and has seen firsthand an increase in the prevalence of fatty livers, type II diabetes, and obesity in his pediatric clientele. He is one of the lead authors of a recent study that explored whether or not restricting fructose in children's diet would impact metabolic syndrome in Latino and African-American children who consumed a lot of sugar and suffer from obesity and metabolic syndrome.¹ His study lasted only nine days and evaluated 43 participants, but the results are worth noting.

During the nine days of the study, the children's food and beverage intake restricted added sugar and substituted complex carbohydrates to essentially maintain the same caloric intake they were accustomed to at baseline. The study was designed to examine the impact of fructose restriction without the confounding factor of weight loss, which independently could explain improvements in metabolic assessments.

Total dietary sugar and fructose were reduced from 10% to 4% daily. Essentially, each participant served as his or her own control. Systolic blood pressure did not change over the test period; however, diastolic blood pressure decreased by 4.9 mm Hg. There was a clinically significant decrease in the heart rate, improvement in glucose tolerance, enhanced insulin sensitivity, and improvements in fasting serum lipids at the end of the nine-day period compared to baseline. Based upon improvements seen in liver function during the period of restricted fructose consumption, the authors hypothesized that excessive dietary fructose causes mitochondrial overload, which in turn results in metabolic syndrome.

A strong message

While critics from the food and beverage industry may strive to minimize results, this is the first study to be able to put fructose on trial, so to speak, and the verdict is revealing. Previous studies have had a difficult time proving causation where fructose is concerned due to factors that this study accounted for. Most studies used short-term protocols featuring an excess dose of oral fructose to examine the effects on metabolic function. In the absence of specific biomarkers for dietary fructose, most studies use dietary recall from participants, which notoriously underestimates sugar consumption.

The outcome of this study simply says yes—for children who are obese, limiting or eliminating the villain fructose shows measurable improvement in metabolic markers within a matter of days! Interestingly, another study published last year revealed that kindergartners' weight was a strong predictor of later childhood obesity.² In fact, when children are obese by age five, they are at a four to five times greater risk of being obese by eighth grade.

Unfortunately, most physicians are not in the habit of sharing a "fructose warning" with pediatric patients and their parents. So where does that leave the average dental professional? With an enormous opportunity before us.

A strong message of what fructose can do to overall health needs to receive greater "air time" from dental professionals. Most of our patients are not aware that data confirms regular consumption of decadent cupcakes, donuts, ice cream, and fructose-laden beverages literally accelerates the movement toward fatty livers, cardiovascular diseases, and type II diabetes. A great place to start in the dental office is to simply ask what beverages patients drink regularly. Most added sugar in the US comes in the form of liquid, from sweetened coffees and teas to energy drinks and sodas. You can even ask patients to list their three most common beverages when they fill out the patient registration form. Initiating the conversation about the dangers of fructose and the benefits of restricting it could have a profound effect and might even save some patients from metabolic syndrome, or worse.

The fact that Americans spend well over $2 billion annually for Halloween candy alone reveals an ongoing disconnect between sugar indulgence and health outcomes for children in this country. It's scary to imagine what health-care costs future generations will bear if daily consumption of fructose doesn't take a serious nosedive. So, colleagues, let's be advocates of restricting fructose to those under our influence. And how about if we lead by example?

References

1. Lustig RH, Mulligan K, Noworolski SM, et al. Isocaloric fructose restriction and metabolic improvement in children with obesity and metabolic syndrome. Obesity 2015. Published online October 2015. doi:10.1002/oby.21371.
2. Gortmaker SL, Taveras EM. Who becomes obese during childhood - clues to prevention. N Engl J Med. 2014; 370:475-476.

Karen Davis, RDH, BSDH, is the founder of Cutting Edge Concepts, an international continuing education company, and practices dental hygiene in Dallas, Texas. She is an independent consultant to the Philips Corp., Periosciences, and Hu-Friedy/EMS. She can be reached at [email protected].