Sugar consumption, metabolic disease and obesity: The state of the controversy

Abstract

The impact of sugar consumption on health continues to be a controversial topic. The objective of this review is to discuss the evidence and lack of evidence that allows the controversy to continue, and why resolution of the controversy is important. There are plausible mechanisms and research evidence that support the suggestion that consumption of excess sugar promotes the development of cardiovascular disease (CVD) and type 2 diabetes (T2DM) both directly and indirectly. The direct pathway involves the unregulated hepatic uptake and metabolism of fructose, which leads to liver lipid accumulation, dyslipidemia, decreased insulin sensitivity and increased uric acid levels. The epidemiological data suggest that these direct effects of fructose are pertinent to the consumption of the fructose-containing sugars, sucrose and HFCS, which are the predominant added sugars. Consumption of added sugar is associated with development and/or prevalence of fatty liver, dyslipidemia, insulin resistance, hyperuricemia, cardiovascular disease and type 2 diabetes, and many of these associations are independent of body weight gain or total energy intake. There are diet intervention studies in which human subjects exhibited increased circulating lipids and decreased insulin sensitivity when consuming high sugar compared with control diets. Most recently, our group has reported that supplementing the ad libitum diets of young adults with beverages containing 0, 10, 17.5 or 25% of daily energy requirement (Ereq) as high fructose corn syrup (HFCS) increased lipid/lipoprotein risk factors for cardiovascular disease (CVD) and uric acid in a dose response manner. However, un-confounded studies conducted in healthy humans under a controlled, energy-balanced diet protocol that allow determination of the effects of sugar with diets that do not allow for body weight gain are lacking. Furthermore, there are recent reports that conclude that there are no adverse effects of consuming beverages containing up to 30% Ereq sucrose or HFCS, and the conclusions from several meta-analyses suggest that fructose has no specific adverse effects relative to any other carbohydrate. Consumption of excess sugar may also promote the development the development of CVD and T2DM indirectly by causing increased body weight and fat gain, but this is also a topic of controversy. Mechanistically, it is plausible that fructose consumption causes increased energy intake and reduced energy expenditure due to its failure to stimulate leptin production. Functional magnetic resonance imaging of the brain demonstrates that the brain responds differently to fructose or fructose-containing sugars compared with glucose or aspartame. There are epidemiological studies which show sugar consumption is associated with body weight gain, and there are intervention studies in which consumption of ad libitum high sugar diets promoted increased body weight gain compared with consumption of ad libitum low sugar diets. However, there are no studies in which energy intake and weight gai...

Introduction of "Sugar Tax" in South Africa: Placebo or panacea to curb the onset of cardio-metabolic diseases?

“…(9) It is important to bear in mind that SSB intake can promote cardio- Long-term, high SSB intake can elicit direct and indirect effects in the body. The glucose and fructose components making up SSBs can trigger perturbations that lead to downstream metabolic and functional effects.…”

Fructose Consumption in the Development of Obesity and the Effects of Different Protocols of Physical Exercise on the Hepatic Metabolism

“…Concomitant with the increased incidence and prevalence of obesity and metabolic syndrome, the consumption of fructose has increased around 30% in the last 40 years [4]. More specifically, because fructose is less able to promote satiety and is more palatable, it will stimulate a higher consumption of food [4], and alter the metabolism of lipids and carbohydrates, thereby favouring the synthesis and accumulation of fat [5]. The accumulation of adipose tissue has come to be considered a global public health problem.…”

Sugar, Cavities, Systemic Disease and Addiction?

“…sucrose) produce greater degrees of metabolic abnormalities than does glucose (either isolated as a monomer, or in chains as starch) and may present greater risk of CHD. To reduce the burden of CHD, guidelines should focus particularly on reducing intake of concentrated sugars, specifically the fructose-containing sugars like sucrose and high-fructose corn syrup in the form of ultra-processed foods and beverages [19] Others have found that consumption of added sugar is associated with development and/or prevalence of fatty liver, dyslipidemia, insulin resistance, hyperuricemia, CVD and type 2 diabetes and failure to stimulate leptin production [20][21][22][23].…”