Dietary, caging and temperature factors in the ageing of collagen fibres in rat tail tendon.

The effect of dietary fat, carbohydrate and protein on tail tendon collagen ageing was studied in male Wistar rats. When rats were fed low-calorie diets there was no evidence that the content of carbohydrate, fat or protein affected the ageing of collagen. However, on high-calorie diets there was evidence that high-fat diets (21%) either saturated or unsaturated aged collagen fibres at a faster than low-fat diets (7%). Isolated housing of rats, which is necessary to control food intake, was found to slow the rate of collagen ageing. This effect was associated with reduced tail tendon temperatures.