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Is Sugar Really a Toxic Substance?


Most of us have experienced a sugar crash before. Some even try to break-up with sugar altogether, saying that avoiding the sweet stuff results in weight loss and better mood. Well, earlier this week, Dr. Robert Lustig took the sugar-is-bad-for-you argument to another level. The California-based endocrinologist told CBS News’ “60 Minutes" that sugar is addictive, toxic, and it's killing us. 

Although his lecture on the negative effects of sugar has been posted on YouTube since 2009, using the word "toxic" and "poisonous" caused quite a stir. So did Lustig's research, which he says shows that sugar causes heart disease, cancer, Type 2 diabetes, and obesity. Although Lustig was not able to comment directly for this piece due to travel, a quick survey of registered dietitians quickly showed that sugar is to be avoided. But how bad it is—and why it's so damaging to the body—varies slightly from expert to expert.

Kathie Madonna Swift, a registered dietitian who teaches at Kripalu Center for Yoga and Health and is the author of The Inside Tract: Your Good Gut Guide to Great Digestive Health, agrees that sugar in excess is toxic. However, she admits that the research on sugar’s role as a dietary contributor to a myriad of health problems is mixed. While some studies have shown a connection between sugar intake and metabolic syndrome, inflammatory disorders and even certain types of cancer, others have not.

However, in her own practice, she's seen the addictive properties of sugar and the benefits of cutting added sweeteners out of the diet. When a person commits to removing sugar from the diet, Swift says that she usually sees improvements in c-reactive protein (an inflammatory marker), fasting insulin, fasting blood sugar, triglycerides, and liver enzymes. 

"Increased sugar consumption via the tsunami now available in the American food supply is clearly one of the most troublesome dietary practices that is fueling chronic disease," Swift says. "At some point, even if the research is not 'pure white,' regarding the damaging effects of sugar, should we not rely on the power of common sense and nutrition intuition to guide us on a sweeter path to health and longevity? Consider the dietary intake of regions in the world with the greatest proportion of centenarians — sugar and sugar-laden foods were not on the menu!"

The average America eats a third of a pound of sugar every day, which adds up to an incredible 130 pounds a year. Marji McCullough, registered dietitian and strategic director of the Nutritional Epidemiology National Home Office of the American Cancer Society agrees that excess sugar consumption plays a role in cancer and other health issues. 

"In excess, yes," McCullough says. "And most people consume it in excess. Excessive consumption leads to weight gain and obesity, both of which are risk factors for cancer and many other diseases. We are in the midst of an obesity epidemic the consequences of which could be devastating especially for the younger generation."   

The problem isn't just us about us adding a little sugar to our coffee or having the occasional piece of cake. The real issue is that sugar — often highly processed in the form of high fructose corn syrup — is everywhere. In addition to desserts, it's also in fast food, breads, yogurt, peanut butter, and sauces.

The American Heart Association recommends that most women have no more than 100 calories per day from added sugar, which equals about 6 teaspoons. For men, the cutoff is 150 calories from added sugars or about 9 teaspoons. The naturally occurring sugars in fruit, milk and yogurt, and some vegetables and grains don’t count towards those totals though, says Mary Hartley, a registered dietitian in New York City.

Hartley isn't ready to call sugar "poisonous" yet. In fact, she says that moderate amounts are OK. It's when you eat too many of them — just like when you eat too much of anything — that things go awry. Excess calories, regardless of source, are harmful to the body because the body doesn’t need the wear and tear of processing more food than it needs, she says.  

"There isn’t a direct scientific link between weight gain in our population and excess calories from sugar," Hartley says. "Sugar has a 'supportive' role but that does not prove cause-and-effect. The real problem with excess sugar is that it can contribute to nutrient deficiencies by supplying calories without providing nutrients (empty calories), and it can contribute to tooth decay." 

If one thing seems to be clear about sugar though, it's that whether or not we agree on how bad it is for us, we should all limit the refined, processed stuff in our diets. In order to eat less sugar, Swift recommends taking a "sweet sabbatical" for at least two weeks to help re-orient your taste buds to the sweet tastes found in nature, including fresh fruit, nuts such as almonds, roasted vegetables, sweet potatoes, unsweetened herbal teas, and spices such as cinnamon, cloves, and allspice. 

So tell us, do you eat sugar and sugary drinks? Try to avoid it except in natural sources like fruit? Do you think its toxic and hurting our health? Share your opinion!


Jennipher Walters is the CEO and co-founder of the healthy living websites and A certified personal trainer, lifestyle and weight management coach and group exercise instructor, she also holds an MA in health journalism and regularly writes about all things fitness and wellness for various online publications.


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