FRUCTOSE IN ENERGY FUELS: RATIONALE AND IMPLICATIONS

By Steve Born

In nearly 40 years in the health food/sports supplement and fuel industry, including almost 24 years employed at Hammer Nutrition, I have not seen another sports nutrition company spend as much time and energy promoting overall health as it does promoting its products (including frequent messaging focused on selling those products).

A longtime friend of Hammer Nutrition once wrote: “An endurance athlete is a healthy person first, an athlete second, and an endurance athlete third.”

That statement reflects why we place significant emphasis on overall health. This is why there have been more articles about healthy eating practices and what to avoid (for example, artificial ingredients, excess sodium, and processed seed oils). Good health is required to obtain benefits from training and to perform well in competition.

Over Hammer Nutrition’s 39+ years, we have frequently discussed the harmful effects of sugar on health and athletic performance. More recently, as there has been renewed interest in consuming very large amounts of carbohydrates (including formulas that use fructose), this raises the need to discuss what we consider the worst substance to consume for health and athletic performance: fructose.

A review of the research on fructose and its adverse effects indicates that it is a substance to avoid. One research paper states: “The increased consumption of fructose in the average diet through sweeteners such as high-fructose corn syrup (HFCS) and sucrose has resulted in adverse outcomes in society, producing considerable economic and medical burden on our healthcare system. Ingestion of fructose chronically has contributed to multiple health consequences, such as insulin resistance, obesity, liver disorders, and diabetes [1].”

Another health concern linked to fructose intake is uric acid (UA) production. Elevated uric acid can lead to gout, which Dr. Bayne French describes as “a truly painful condition.” Dr. French also writes that elevated UA “drives the formation of insulin resistance, elevated blood sugar, type 2 diabetes, heightened blood pressure, distorted cholesterol, systemic inflammation, and weight gain. It is directly implicated in a large percentage of all-cause mortality, especially from cardiovascular disease.”

According to Dr. French, “on its own, elevated uric acid corresponds with disease.”

Uric acid is also produced from alcohol and purines, but fructose can reasonably be considered a primary contributor. One reason is that fructose intake has increased for decades. Research has reported that fructose intake per person rose by approximately 32% from the 1970s to the early 2000s [2]. Given the widespread presence of fructose in foods and beverages and predicted dietary patterns (higher fructose consumption), fructose intake likely increased beyond 32% over the past 15–20 years.

Another reason fructose is a leading candidate for uric acid production comes from a study analyzing fructose consumption in 21,483 individuals aged 2 to 71+. The results estimated mean fructose intake at 54.7 g/day (range 38.4–72.8 g/day), accounting for 10.2% of total caloric intake. Intake was highest among adolescents (12–18 years) at 72.8 g/day (12.1% of total calories), and one-fourth of adolescents consumed at least 15% of calories from fructose [3]. Because many participants were younger and likely consumed limited alcohol and fewer purine-rich foods, fructose appears to be the most likely contributor to uric acid production in this context.

An important point noted in Dr. French’s article is that elevated uric acid and gout are associated with sugar-sweetened beverages, but not with whole fruit consumption. Research has also reported a similar pattern for coronary heart disease (CHD). A study in The American Journal of Clinical Nutrition [4] concluded: “Intakes of TGE (glucose monosaccharides, disaccharides, and starch), total sugar, added sugar, and fructose from added sugar and juice were associated with higher CHD risk, but TFE (fructose monosaccharides and sucrose) and fructose from fruits and vegetables were not.”

Lead researcher Dr. Kristine K. Dennis summarized: “For prevention of CHD, diets emphasizing whole fruits and vegetables while limiting added sugars and refined starches should be encouraged. Our research aligns with other evidence that whole fruit appears to have a protective role, regardless of fructose content. At the same time, it also aligns with other evidence suggesting that carbohydrate quality is important for cardiovascular disease risk.”

Fructose in energy fuels: rationale and implications

The information above represents only a small portion of the research describing negative health effects associated with fructose intake from sources other than whole fruits and vegetables. The central point is that fructose is harmful to health. This leads to a practical question: why do companies continue to use fructose in energy fuels marketed to athletes? If fructose is harmful to general health, it is unclear how it would improve athletic performance.