Year 8 Science - Cells: Diabetes

Consumption of sugar, specifically sugar-sweetened beverages, has been widely held responsible by the media for the global rise
in Type 2 diabetes (T2DM).
Areas of controversy: Much of the association between sugars and T2DM
is eliminated by adjusting data for body mass index (BMI). However, BMI
adjustment does not fully account for adiposity (r
2
=0.65–0.75). Excess
sugar can promote weight gain, thus T2DM, through extra calories, but has
no unique diabetogenic effect at physiological levels.

Globally, type 2 diabetes mellitus (T2DM) is considered as one of the most common diseases. The etiology of T2DM is complex and is associated with irreversible risk factors such as age, genetic, race, and ethnicity and reversible factors such as diet, physical activity and smoking.

We investigated the effects of diet-induced obesity on
glucose metabolism in two strains of mice, C57BL/6J
and A/J. Twenty animals from each strain received
ad libitum exposure to a high-fat high-simplecarbohydrate diet or standard Purina Rodent Chow
for 6 mo. Exposure to the high-fat, high-simplecarbohydrate, low-fiber diet produced obesity in both
A/J and C57BL/6J mice. Whereas obesity was
associated with only moderate glucose intolerance and
insulin resistance in A/J mice, obese C57BL/6J mice
showed clear-cut diabetes with fasting blood glucose
levels of >240 mg/dl and blood insulin levels of >150
^ll/ml. C57BL/6J mice showed larger glycemic
responses to stress and epinephrine in the lean state
than AJ mice, and these responses were exaggerated
by obesity. These data suggest that the C57BL/6J
mouse carries a genetic predisposition to develop
non-insulin-dependent (type II) diabetes. Futhermore,
altered glycemic response to adrenergic stimulation
may be a biologic marker for this genetic
predisposition to develop type II diabetes. Diabetes
37:1163-67,1988

In recent decades, temporal patterns in SSB intake have shown a close parallel between the upsurge in obesity and rising levels of SSB consumption. SSBs are beverages that contain added caloric sweeteners such as sucrose, high-fructose corn syrup or fruit-juice concentrates, all of which result in similar metabolic effects. They include the full spectrum of soft drinks, carbonated soft drinks, fruitades, fruit drinks, sports drinks, energy and vitamin water drinks, sweetened iced tea, cordial, squashes, and lemonade, which collectively are the largest contributor to added sugar intake in the US. It has long been suspected that SSBs have an etiologic role in the obesity epidemic, however only recently have large epidemiological studies been able to quantify the relationship between SSB consumption and long-term weight gain, type 2 diabetes (T2DM) and cardiovascular disease (CVD) risk.

Added Sugars and Type 2 Diabetes. Recent meta-analyses indicate that consumption of sugar, added sugars or total sugars does not increase the risk of Type 2 Diabetes. Epidemiological studies suggest an association between drinking large amounts of sugars-sweetened beverages and an increased risk of Type 2 Diabetes; however this may be due to an overall unhealthy lifestyle pattern.