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310 Myrtle Street
Apartment 306
Mount Vernon, WA 98273
E-mail: njkrilanucla{at}hotmail.com
Dear Sir:
We have failed our children (1). The surging worldwide obesity epidemic is catastrophic enough, but look at the steady stream of bad news hitting our biochemically immature little ones: both adult-onset diabetes and nonalcoholic fatty liver disease (2) as early as the age of 4 y, a great rise in the incidence of pertussis and asthma, and, in the mental area, an alarming increase in autism, ritalin use, bipolar disorder, anxiety, and the use of antidepressants in preschool children. With a lifetime to progress to even more-serious problems, the problems of children are far worse than most people seem to realize.
Fortunately, the solution is in the scientific literature. The article by Bray et al (3) in the April issue of the Journal advanced the search for a solution with emphasis on fructose and beverages, but there were errors of commission and of omission in this article. In Figure 1 of Bray et al's article, according to their reference 35, the most recent data point for the percentage prevalence of obesity should be 30.9%, not 26%, and at least some of the data points for the prevalence of overweight should be much higher. The correct values emphasize the recent rapid rise in obesity and increase the urgency of the problem.
Bray et al made good use of the data in their reference 34, but they seemed to miss the extra significance for the child represented by the data in Figure 6 in the 1993 article by Park and Yetley (4). The mean daily intake of fructose (in g/kg body wt) from birth to age 80 y is shown in Figure 6. At age 20 y, the daily intake of total fructose was 0.62 g/kg, and it slowly decreased with age, whereas the naturally occurring fructose intake at age 20 y was 0.2 g/kg. At ages <20 y, however, it was astonishing that the daily intake of total fructose remained >1.9 g/kg body wt from near birth to about the age of 4 y. Through the years of their postnatal brain growth spurt, infants and toddlers are fed 10 times the amount of naturally occurring fructose ingested by adults.
What is a reasonable guess for the daily intake of total fructose for an infant from the Stone Age? Zero. They must have been fed mother's milk, the sugar in which is lactose, which digests to galactose and glucose only. Note that the ratio between the amount of fructose our infants are being fed today and the amount they were fed when our genes were adapting to the environment approaches infinity.
Bray et al pointed out many differences between fructose and glucose, with more troubles from fructose. "It is becoming increasingly clear that soft drink consumption may be an important contributor to the epidemic of obesity, in part through the consumption of larger portion sizes of these beverages and through the increased intake of fructose from high-fructose corn syrup and sucrose." Bray et al referenced Elliott et al (5), who cited more differences between glucose and fructose in their major review. They concluded in part, "...on the basis of the available data regarding the endocrine and metabolic effects of consuming large quantities of fructose and the potential to exacerbate components of the insulin resistance syndrome, it is preferable to primarily consume dietary carbohydrates in the form of glucose (free glucose and starch)." Others concluded that, "if plasma triacylglycerols are a risk factor for cardiac disease, then diets high in fructose may be undesirable...efforts to reduce fructose intake should focus on reducing the amount of fructose added to beverages and foods in the American diet. A reduction in added fructose would be facilitated by an acceptable replacement sugar. Such a sugar might be glucose (6)." Wharton and Hampl (7) concluded that, "Native Americans face some of the highest rates of obesity and diabetes in the world...little attention has been paid to reducing fructose, particularly in the form of HFCS [high-fructose corn syrup] in beverages...numerous studies have documented that beverages are a leading contributor to energy intakes among Native Americans... one approach may be by promoting sugar-free beverages." The titles of the studies by Levi et al (8) and Suarez et al (9) point to additional alarming troubles associated with fructose intake.
Basic biochemistry indicates that glucose and fructose have different chemical properties. Of the 3 major sugars that digest into the human bloodstream, the 2 that are vital to humans, galactose and glucose, are both aldoses, whereas fructose is a ketose—this sugar is the one that the human liver tries hard to keep at essentially a zero concentration in the blood. Murray et al (10) wrote that, "Biomedically, glucose is the most important monosaccharide and ingestion of large quantities of fructose has profound metabolic consequences ...because it bypasses the regulatory step catalyzed by phosphofructokinase. This allows fructose to flood the pathways in the liver, leading to enhanced fatty acid synthesis, increased esterification of fatty acids, and increased VLDL secretion, which may raise serum triacylglycerols and ultimately raise LDL cholesterol concentrations."
Could fructose contribute to nonalcoholic fatty liver disease? With all the documented troubles from fructose, it is clear that the low glycemic index of fructose is misleading at best. The main source of fructose for infants and toddlers is fruit juice and soda. The nutrition-facts labels indicate that both sources are essentially the same, that is, sugar water that digests to nearly equal amounts of glucose and fructose. Of course, more trouble results from the faster sugar ingestion from a water solution than from sugar in solid foods, as noted by Bray et al.
Three summarizing facts call for immediate resolution: 1) we are flooding our infants and toddlers with fructose, 2) we are doing this through their entire postnatal brain growth spurt, and 3) infants and toddlers are being flooded with severe health problems, including brain disorders. How effective is the liver of infants and toddlers in keeping fructose out of their blood? How effective is their blood-brain barrier in keeping fructose out of their brain? Would there be any harm from withholding fructose until an age at which this population could handle whole fruit? How much does the surging worldwide sale of sugar water contribute to the surging obesity epidemic? Should fructose be withdrawn from the list of "generally recognized as safe" substances?
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