Submitted to: North Dakota Academy of Science Proceedings
Publication Type: Other
Publication Acceptance Date: September 30, 1997
Publication Date: N/A
Interpretive Summary: Since the introduction of high-fructose corn sweeteners in 1967, per capita consumption of fructose has increased markedly in the United States. It has been estimated that fructose consumption accounts for more than 10% of the total energy intake of United States citizens, and some intakes, especially those of heavy consumers of soft drinks, probably approach 15% of dietary energy. Another common occurrence among United States citizens is the consumption of diets that supply significantly less that the recommended dietary allowance for magnesium. Studies with rats have indicated that high dietary fructose can affect the need for magnesium, and an interaction between these two nutrients can affect macromineral (e.g., calcium, phosphorus) metabolism. Thus, an experiment was performed with men between the ages of 22 and 40 years housed in a metabolic ward to ascertain whether an interaction between fructose and magnesium affects macromineral metabolism in humans. This study showed that dietary fructose significantly affected magnesium, calcium and phosphorus balances (the amount loss or retained by the body each day). With a low fructose diet (high starch), magnesium balance findings indicated that 170 mg/day of magnesium is inadequate for men. High dietary fructose decreased calcium (especially when dietary magnesium was low) and phosphorus balances, which indicates that dietary fructose affects macromineral metabolism in humans. Further studies are warranted to see if a high fructose diet with low dietary magnesium and marginal calcium leads to bone loss.
Technical Abstract: Studies with rats have found that an interaction between dietary fructose and magnesium affects macromineral metabolism in rats. Thus, an experiment was performed with men between the ages of 22 and 40 years housed in a metabolic ward to ascertain whether an interaction between fructose and magnesium affects macromineral metabolism in humans. Eleven men participated in four dietary periods of 42 days in which dietary magnesium was either approximately 170 or 370 mg/day, and dietary fructose was either 4% or 19% of energy. A decaffeinated beverage containing high fructose corn syrup replaced cornstarch, bread and rice in the low fructose diet to give the high fructose diet. Results showed that dietary fructose significantly affected magnesium, calcium and phosphorus balances. With the low fructose diet (high starch), when dietary magnesium was about 170 mg/day, magnesium balance was -14 mg/day; because this value is markedly lower than when dietary magnesium was 370 mg/day (balance was 29 mg/day), an intake of 170 mg/day is probably inadequate for men consuming a high starch diet. Although fructose improved magnesium balance, it depressed calcium balance with the effect more marked when dietary magnesium was low. High dietary fructose also decreased phosphorus balance and increased the concentration of alkaline phosphatase in plasma. The findings indicate that dietary fructose affects macromineral metabolism in humans.