Differences reported in the lifespan and aging of male Wistar rats maintained on diets containing fat with different fatty acid profiles (virgin olive, sunflower or fish oils) are not reflected by histopathological lesions found at death in central nervous and endocrine systems.

The present study was designed to examine if dietary fat sources that have shown differences in lifespan and if some aging-related aspects can modulate the range of histopathologic changes in central nervous and endocrine systems that occur during the lifespan of Wistar rats. Moreover, it was attempted to gain insight into the relationship between longevity and the development of the different pathological changes, as well as possible interaction with diet. In order to achieve this, male Wistar rats were randomly assigned to three experimental groups fed semisynthetic and isoenergetic diets from weaning until death with different dietary fat sources, namely virgin olive, sunflower, or fish oil. An individual follow-up until death of each animal was performed. Incidence, severity, and burden of specific or group (i.e., neoplastic or non-neoplastic proliferative and non-proliferative) of lesions was calculated along with individual's disease and individual organ lesion burden. Most of the histopathological lesions found have been described in previous studies. Neoplasms, and in particular pituitary adenomas followed by brain tumors, were the most prevalent lesions found in the rats and the main cause of death involving both systems. Incidence of brain lesions was associated with age-at-death. Assayed dietary fats did not present differential effects on pathological changes occurring in endocrine and central nervous systems throughout rat lifespan.

Longevity and Cause of Death in Male Wistar Rats Fed Lifelong Diets Based on Virgin Olive Oil, Sunflower Oil, or Fish Oil.

Extending life by delaying the aging process has been proven to be the most effective way to fight multiple chronic diseases in elderly adults. Evidence suggests that longevity is inversely related to unsaturation of membrane phospholipids. This study investigated how different unsaturated dietary fats affect life span and cause of death in male Wistar rats fed diets based on virgin olive oil (V), sunflower oil (S), or fish oil (F), which were supplemented or not with Coenzyme Q10 (CoQ10). Previous results suggest that individual longevity and survival probability at different ages may be modulated by an appropriate dietary fat treatment. Lifelong feeding with V or F diets would reduce death probability compared to feeding with S diet at certain ages, although the effects of V diet would be maintained for most of life. Furthermore, the addition of lower amounts of CoQ10 reduced mortality associated with S diet, but CoQ10 had no effect on survival when combined with virgin olive oil or fish oil. Supplementation with low doses of CoQ10 failed to increase the maximum life span potential of rats fed a V or F diet. No clear evidence showing that monounsaturated fatty acids, n-3 polyunsaturated fatty acids, or CoQ10 exerted the observed effects by modulating the rate of aging has been found.