The Effects of One Month High Fructose Intake on Plasma Glucose and Lipid Levels in Non‐insulin‐dependent Diabetes

Abstract

The effects of a high fructose diet on the control of blood glucose and serum lipids were studied in 10 non-insulin-dependent diabetic patients (mean age 64.4 years, mean duration of diabetes 5.6 years). Comparison was made following 28 days on the usual diabetic diet and 28 days during which 25% of the usual carbohydrate was substituted with fructose. There was no change in mean (+/- SEM) fasting plasma glucose (on usual diet 9.2 +/- 0.5 mmol/l, on fructose diet, 9.1 +/- 0.4 mmol/l), but there was a fall in mean plasma glucose levels at 30, 60, and 120 min in a 75 g OGTT following the fructose diet. There was no significant change in fasting lipids: on usual diet mean serum cholesterol 5.8 +/- 0.2 mmol/l, on fructose diet 5.6 +/- 0.2 mmol/l; serum triglyceride, on usual diet 1.3 +/- 0.1 mmol/l, on fructose diet 1.3 +/- 0.1 mmol/l; HDL cholesterol on usual diet 1.4 +/- 0.1 mmol/l, on fructose diet 1.4 +/- 0.1 mmol/l. Mean body weight did not vary significantly between the two diets. Incorporation of fructose into the diabetic diet may lower post-prandial glucose levels without disturbing serum lipids.

Metabolic Effects of Dietary Sucrose and Fructose in Type II Diabetic Subjects

“…Regarding lipid metabolism, there has been some concern about the occurrence of detrimental effects of high-fructose diets in diabetic patients (35,36), despite bulky evidence against it (8,(32)(33)(34)(37)(38)(39). As a matter of fact, the increase in fasting triglycerides observed by Grigoresco et al (36) when supplementing fructose for 2 months to diabetic subjects may not have been related to fructose itself, as it was not statistically different from that which also occurred with their control starch diet.…”

“…It is more slowly absorbed from the gastrointestinal tract than glucose (30), is rapidly taken up and converted into the liver to glycogen, triglycerides, and CO2 (31), is sweeter than sucrose, and its initial metabolism is independent of insulin action. The majority of the studies focusing on the influence of dietary fructose on the glucose metabolism of diabetic patients have demonstrated either beneficial or neutral effects (4,5,8,12,(32)(33)(34)(35)(36)(37). The long-term studies, although limited in number, have shown an absence of detrimental effects of fructose on the carbohydrate metabolism, whereas in the short term the beneficial effects are more easily observed.…”

Metabolic Effects of Fructose and the Worldwide Increase in Obesity

“…These studies reported conflicting results, in part explained by variations in experimental conditions (duration of treatment, type of carbohydrate replaced by fructose in the diet, etc.). Only about half of them resulted in a significant reduction in blood glucose (10,14,16,55,56,85,139,154,210,211). These studies however pointed out the fact that fructose was associated with a substantial increase in plasma triglyceride and a decrease in highdensity lipoprotein (HDL)-cholesterol.…”

Current Issues in Fructose Metabolism

“…Conflicting results may be explained, at least partly, by differences in experimental conditions, e.g. animal versus human studies, the duration of feeding, the background diet, the degree of metabolic control of the subjects, or the type of carbohydrate replaced by fructose in the diet (3,4,9,13,23,24,44,45,61,68,73,96,97,105,110).…”