The interaction of type of dietary carbohydrates with copper deficiency

Abstract

The present study was designed to determine if the more severe copper deficiency in rats fed sucrose and fructose, as compared to starch, is due to a specific effect of the fructose or to a nonspecific effect of any simple carbohydrate. Seventy weanling male rats were fed, for 9 wk, copper-deficient diets or copper-supplemented diets containing either 62% starch, fructose, or glucose. Decreased hematocrit, serum copper, and ceruloplasmin concentrations but increased heart and liver weights, total liver lipid, and hepatic iron concentrations were found in all copper-deficient rats regardless of the dietary carbohydrate. Feeding rats the high glucose diet decreased plasma albumin and liver glycogen but increased blood urea nitrogen when compared to rats fed starch. However, rats fed fructose generally exhibited a more severe copper deficiency as compared to rats fed either starch or glucose. The severity was characterized by lower (p less than 0.05) body weight, liver glycogen, hematocrit, serum copper, and albumin. Conversely, liver and heart weights, blood urea nitrogen, and plasma glutamic oxaloacetic transaminase were higher (p less than 0.05). Plasma cholesterol was increased by copper deficiency only in rats fed fructose or glucose. During the study, 17 of the 40 rats fed copper-deficient diets died; 66% of those fed fructose, 26% fed glucose, and 30% fed starch. These results suggest that the fructose moiety of sucrose is responsible for the increased severity of copper deficiency in rats fed sucrose as compared to starch.

The Role of Copper as a Modifier of Lipid Metabolism

“…Follow-up work indicated that when diets with fructose, glucose or starch were combined with copper deficiency, both glucose and fructose raised plasma cholesterol levels. However, severity of copper deficiency and mortality were much greater with fructose as opposed to glucose feeding (65), suggesting that the exacerbation of copper deficiency by sucrose was due to the fructose component. More recent work (66) indicates that the effect of fructose may be at the level of absorption, whereby copper deficiency induces upregulation of the copper transporter Ctr1, but this effect is eliminated by high fructose feeding (Figure 1).…”

Effects of Antihypertensive and Triglyceride‐lowering Agents on Hepatic Copper Concentrations in Rats with Fatty Liver Disease

“…and plasma and hepatic triglyceride concentrations and thus exaggerate hepatic inflammation [20,21]. It is suggested that dietary fructose, in addition to its metabolic effects, may also impair gut absorption of copper by inhibiting the copper transporter located in the duodenal and proximal jejunum [10,22].…”

Alterações metabólicas e funcionais do cobre em diabetes mellitus

“…Neste contexto, o tipo de carboidrato da dieta constitui também um fator importante na utilização do cobre, sendo a frutose o mais investigado, principalmente em estudos de deficiência deste mineral (Reiser et al, 1983;Fields et al, 1984;Fields et al,1986;Werman & Bhathena, 1992).…”

“…Experimentos delineados para testar os efeitos do consumo de frutose ou amido na deficiência de cobre têm mostrado que ratos machos alimentados com dietas deficientes em cobre contendo frutose apresentam sinais de deficiências mais graves do que os ratos alimentados com amido (Reiser et al,1983;Fields et al, 1984). Acrescentando-se o fato de que ratas alimentadas com dietas deficientes em cobre parecem estar protegidas desses efeitos (Fields et al, 1986;Werman et al, 1995), tem-se sugerido que os animais metabolizam frutose de forma diferente, dependendo do sexo.…”