Sugar, just empty calories or something more sinister?
For the month of March, our resident nutritionist Melinda Bakker is sharing her thoughts on sugar and some of the new research emerging on the dangers of the sweet stuff. This is part one in a two-part series on sugar. Also, for more of Melinda’s health insights, be sure to check out our Twitter feed where she shares news and handy tips and facts!
When I was preparing for grad school, my supervisor kindly gave me an older (1997) version of a nutrition textbook. When I reached the section on carbohydrates, the author addressed the question of whether or not sugar was bad for you. The answer was as follows:
“Some people think that sugar consumption is unhealthy… However, if you can afford to consume some extra calories, moderate amounts of sugar are not harmful. Scientists think that sugar is mostly a problem when it is eaten at the expense of more nutritious foods. When this happens, a person could become deficient in vitamins and other important nutrients, especially if restricting energy intake from other sources.”
I remember being shocked by this statement – was it really true that added sugar in moderation isn’t harmful? Does sugar just provide ‘empty calories’ or is there a more dangerous side to added sugar? The answer provided by the author shows that he subscribed to the ‘empty calorie’ theory, viewing sugar as okay as long as is not consumed at the expense of healthy foods containing vitamins and minerals.
Even more recently, the 2010 Dietary Guidelines Advisory Committee (DGAC) for Americans suggested a maximum intake of 25% of total energy from added sugars, implying that at this level sugar consumption does not have adverse effects.Their rationale was “based on dietary intake survey data showing that people with diets at or above this level of added sugars were more likely to have poorer intakes of essential nutrients.” Once again, the theory is that sugar provides calories at the expense of essential nutrients.
While it is true that excessive consumption of sugar in place of healthy foods could lead to nutritional deficiencies, I believe that this is only part of the story and that high consumption of processed sugars will have negative effects on your metabolism that go beyond the extra calories. I also think that the sugar industry would like to have you believe that added sugar is just ‘empty calories’. That way, as long as you consume some healthy foods alongside your massive sugar intake and try not to consume too many calories overall, you should be fine, right?
While this is still a subject of scientific debate, I think the tide is turning and many scientists are pointing out the detrimental effects of added sugars. One scientist, Dr Lustig, a professor of pediatrics at the University of California, San Francisco is a leading proponent of reducing sugar consumption. He states that “as long as the public thinks that sugar is just ‘empty calories,’ we have no chance in solving this.”
Increased sugar intake has been found to alter many metabolic processes that may increase risk of a host of chronic diseases. In particular, the fructose found in added sugars wreaks havoc on the liver and promotes increased synthesis of fats. Sugar is thought to increase metabolic disease indirectly by increasing body weight and also directly by its negative effects on lipid and carbohydrate metabolism.
In my next blog post I will explain what happens to the sugar in your body and why high levels of added sugars have negative health effects.
To read more on on the research Melinda touches on in this post, below are some handy references:
Wardlaw, G. M. Contemporary nutrition: issues and insights. Third edition. (McGraw-Hill, 1997).
Report of the dietary guidelines advisory committee on the dietary guidelines for Americans, 2010. at <http://www.cnpp.usda.gov/DGAs2010-DGACReport.htm>
Bunim, J. Societal control of sugar essential to ease public health burden. at <http://www.ucsf.edu/news/2012/02/11437/societal-control-sugar-essential-ease-public-health-burden>
Lustig, R. H., Schmidt, L. A. & Brindis, C. D. Public health: The toxic truth about sugar. Nature 482, 27–29 (2012).
Stanhope, K. L., Schwarz, J.-M. & Havel, P. J. Adverse metabolic effects of dietary fructose: results from the recent epidemiological, clinical, and mechanistic studies. Curr. Opin. Lipidol. 24, 198–206 (2013).