Sugary Beverages and Their Bitter Effects

11/23/2011 04:49 pm ET | Updated Jan 23, 2012
  • Eric Ding, Ph.D. Nutritionist, Epidemiologist, Econometrics | Harvard University


Photo: Harvard School of Public Health

I'm often asked the question, "What is the single most harmful food in our diet today?" Although we have identified numerous harmful foods, over the years from studying nutrition and disease risk, the evidence is mounting that it is the excess consumption of sugary beverages in our diet. Actually, it's not just mounting -- the science is now "double-rainbow" -- overwhelming that it is astronomically harmful, and likely exerts an immense toll on mortality and quality of life.

Indeed, American consumption of sugar-sweetened beverages (SSBs) has more than doubled since the late 1970s, and they are now considered the primary source of added sugar in the U.S. diet. And science is showing that sugary beverages cause many diseases, perhaps more than other foods.

However, don't get me wrong -- ironically, I'm actually not anti-sugar critic per se (and the scientific jury is still out on high-fructose corn syrup). Although I'm not a fabulous fan of the empty-calorie nature of sugar, a sugar cube is not the direct culprit to blame. Nor is water. It is, however, when these two ingredients combine -- into liquid sugar. Indeed, the dangers of SSBs emerge when sugar becomes dissolved in liquid, which has strong negative effects in causing malfunctions in your appetite control, leading to excess hunger.

The difference between liquid sugar and solid sugar is best seen in an experiment between sugary beverages vs. jelly beans (with same number of calories). While jelly bean eaters become full and ate less food later in the day, liquid sugar drinkers were not fully satiated and become hungrier sooner and consumed more calories at the end of the day (compared to solid sugar eaters). This is why sugary beverages (but not sugar) are inherently dangerous -- because liquid sugar is partially "invisible" to our hunger control system.


Photo: JAMA

Moreover, SSBs also causes separate metabolic effects through their contribution to a high dietary glycemic load, leading to inflammation, insulin resistance and impaired pancreas function, in addition to accumulation of fat tissue and obesity. All these contribute to increased risk of many various chronic diseases that our Harvard research has shown time and time again (see the slideshow below of harmful effects).

All in all, such is why many nutrition scientists label liquid sugar as a "metabolic poison," and the reason many nutritionists highlight sugar-sweetened beverages as one of the most harmful foods in our diet.

A bitter drink to swallow, indeed. Let's all eat a hard dark chocolate bar instead.

8 Harmful Effects of Sugary Drinks

8 Harmful Effects of Sugary Drinks

Dr. Eric Ding is a nutritionist and medical researcher at Harvard University, and founder of the Campaign for Cancer Prevention.

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