Calorie Restriction and Age-Related Gene Expression Changes in the Brain
The practice of calorie restriction with optimal nutrition, a lowered calorie intake while maintaining necessary dietary micronutrient levels, slows near all measures of aging in laboratory animals such as mice. The human studies of calorie restriction show pretty impressive results on shorter term measures of health, greater benefits than any presently available medical technology can provide to an essentially healthy individual at any age. If calorie restriction was a drug, it would be a household name, which probably explains why so much effort is devoted to the development of calorie restriction mimetic drugs. Sadly that is actually a very poor approach to producing treatments for aging, as the calorie restriction response is exceedingly complex: near everything in the operation of metabolism changes in response to lowered food intake, researchers are nowhere near the level of understanding required to proceed effectively, and even if successful the end results will be of only slight benefit.
Thus we shouldn't take our cues for the future of longevity science from its past investigations of natural variations in longevity: the future must look more like engineering, an undertaking in which researchers attempt to repair the cellular and molecular damage that causes aging rather than work on ways that merely gently slow down the damage accumulation. You can't use calorie restriction to reliably live to age 90 and beyond, it just modestly improves your odds. The only way to reliably live much longer in good health is to develop actual, working rejuvenation treatments based on damage repair as a strategy.
In any case, here is an example of the sort of research that helps to maintain the presently high level of interest in calorie restriction mimetic development among researchers:
Neuroscientists [have] shown that calorie-reduced diets stop the normal rise and fall in activity levels of close to 900 different genes linked to aging and memory formation in the brain. Researchers say their experimental results, conducted in female mice, suggest how diets with fewer calories derived from carbohydrates likely deter some aspects of aging and chronic diseases in mammals, including humans. "Our study shows how calorie restriction practically arrests gene expression levels involved in the aging phenotype - how some genes determine the behavior of mice, people, and other mammals as they get old. [It adds] evidence for the role of diet in delaying the effects of aging and age-related disease."While restrictive dietary regimens have been well-known for decades to prolong the lives of rodents and other mammals, their effects in humans have not been well understood. Benefits of these diets have been touted to include reduced risk of human heart disease, hypertension, and stroke, [but] the widespread genetic impact on the memory and learning regions of aging brains has not before been shown. Previous studies [have] only assessed the dietary impact on one or two genes at a time, but [this] analysis encompassed more than 10,000 genes. For the study, female mice, which like people are more prone to dementia than males, were fed food pellets that had 30 percent fewer calories than those fed to other mice. Tissue analyses of the hippocampal region, an area of the brain affected earliest in Alzheimer's disease, were performed on mice in middle and late adulthood to assess any difference in gene expression over time.