Health Benefits From Diets High in Salicylates May Arise From Improved Utilization of Dietary Copper

Suliburska and Cholik¹ suggest that dietary salicylates can result in blood and urinary concentrations comparable to those observed in patients taking low-dose aspirin. These diets may have anti-inflammatory effects affected by nitric oxide and superoxide anion along with antidiabetic benefits. The authors suggest that dietary salicylates can interact with drugs; perhaps they also interact with dietary nutrients.

Aspirin (acetylsalicylic acid) fed to rats deficient in copper doubled the copper concentrations in liver microsomes, perhaps contributing to the decreased plasma cholesterol observed.² Copper deficiency has adverse effects on the metabolism of glucose and cholesterol and alters nitric oxide physiology.³ Several superoxide dismutase enzymes depend on copper for oxidative defense.⁴ Copper deficiency in mice promotes thrombosis.⁵

Copper in the Western diet has decreased since the 1930s to a point where more than 70% of diets analyzed chemically contain less than 1 mg daily, an amount proved to be insufficient for men and women in carefully controlled depletion experiments.⁶ Two of these men depleted of copper in a metabolic ward responded with decreased glucose tolerance.⁷

Aspirin (and probably most salicylates) is one of a dozen cuprotropic and cholesterotropic chemicals. Some of these, such as calcium, clofibrate, and sodium phytate, improve copper metabolism and lower cholesterol. Several others, such as ascorbic acid, cadmium, and histidine, have opposite effects on both copper and cholesterol.⁸

Glucose intolerance in copper deficiency has been known for nearly a century.^7,9 Suliburska and Cholik¹ mention ginkgolic acid, a derivative of salicylic acid with beneficial effects on glycogen synthesis and blood glucose. Perhaps some of the cholesterotropic chemicals above are glucotropic as well.

In conclusion, it seems likely that some of the benefits of dietary salicylates cited by the authors occur because of improved copper utilization of people consuming diets low in copper. Glucose metabolism, diabetes mellitus, and cardiovascular diseases treated with low-dose aspirin to prevent thrombosis may be most important.

Conflicts of Interest

None declared.

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