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Pennington Biomedical Research Center
6400 Perkins Road
Baton Rouge, LA 70808-4124
E-mail: brayga{at}pbrc.edu
University of North Carolina–Chapel Hill
Chapel Hill, NC
Dear Sir:
Krilanovich has written a stimulating and provocative letter to the Editor with a call to action based on our critique of high-fructose corn syrup (HFCS). He has pointed out a significant error in our Figure 1 (1) and emphasized the potentially detrimental effects of fructose during the period of brain maturation in children. His letter serves to highlight this additional area of concern, and we applaud him for that.
At the end of our article (1) we stated that, "...we believe that an argument can now be made that the use of HFCS in beverages should be reduced and that HFCS should be replaced with alternative noncaloric sweeteners." On the basis of the special issues relating to fructose and children that were highlighted by Krilanovich, which we did not dwell on, we support his suggestion that a reduction or elimination of fructose from HFCS as well as in sucrose in beverages available to infants and children could be a high-priority nutritional policy.
We thank Krilanovich for pointing out the error in our Figure 1. He is absolutely correct that the prevalence of obesity was 30.5% in 2000, not 26%. We submitted an amended figure to the Journal, which was published in response to an earlier letter (2). As Krilanovich noted, the correct value makes the rise in the prevalence rates of obesity more evident and the temporal relation of the increasing use of HFCS clearer.
Since our paper was published, a subsequent analysis of carbohydrate intake in relation to the prevalence of diabetes was published by Gross et al (3). Their observations dovetail with ours. They showed a decline in carbohydrate intake of from 500 g per capita in 1910 to 362 g per capita during the first three-quarters of the 20th century. Thereafter, carbohydrate intake returned to the same level as earlier in the 20th century. HFCS represents almost all of the increased carbohydrate during this latter period. Their study also nicely highlights the temporal relation of this change in carbohydrate intake with the rising incidence of diabetes.
Nature prefers glucose and rejects fructose. Fructose does not enter the brain or pancreas to any appreciable degree. Yet fructose is considerably sweeter than either glucose or sucrose. As Krilanovich points out, infants and young children in our society are exposed to higher intakes of fructose than were our ancestors. The fructose from HFCS used in beverages differs from the fructose combined to form sucrose in 2 ways. First, it is free fructose and as such is sweeter molecule for molecule than is sucrose or glucose—the other half of the sucrose molecule. In addition, HFCS solutions have a higher osmotic pressure than do equimolar sucrose solutions, because there are 2 molecules in the HFCS solution (fructose and glucose) compared with a single molecule in sucrose. This enhanced sweetness and high osmolarity may serve to stimulate the taste receptors more intensely and to "imprint" this intense taste in the plastic neurocircuitry of young and growing brains, a change that may increase the desire for sweet taste throughout life. If this is even a remote possibility, the suggestion by Krilanovich to eliminate the exposure of infants and children to fructose might be worth serious consideration. As we know, intrauterine exposure to maternal smoking (4) or diabetes (5) enhances the risk of obesity and overweight later in life. Thus, we support Krilanovich in encouraging a review of whether exposure to fructose either as HFCS or in sucrose during the early years of life may play an important role in the current epidemic of obesity in children (6). If there is even a suggestion that this is so, then access by infants and young children to beverages with fructose should be curtailed during critical periods of brain growth and development.
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