Researcher Jon Ramsey, PhD is Professor in the Department of Molecular Biosciences within the School of Veterinary Medicine at UC Davis. His study of animals focuses on nutrition as it relates to obesity and aging. The goal of his research is to understand the biological mechanisms that contribute to the aging process and to develop dietary interventions that promote healthy aging and weight loss. In this podcast, NBT Scientific Director Megan Roberts interviews Dr. Ramsey about his research in the area of calorie restriction and its beneficial effects on longevity and healthspan. They examine the scientific literature on energy and macronutrient restriction, including some of the possible biological mechanisms driving the anti-aging effects of these interventions. They also discuss what this all means in practical terms for those seeking optimal health as they age. Here’s the outline of this interview with Jon Ramsey: [00:01:35] Calorie restriction for increasing lifespan. [00:02:01] Theories of aging. [00:04:40] Osborne and Mendel; Study: Osborne, Thomas B., Lafayette B. Mendel, and Edna L. Ferry. "The effect of retardation of growth upon the breeding period and duration of life of rats." Science 45.1160 (1917): 294-295. [00:04:58] Clive McCay; Studies: McCay, Clive Maine, and Mary F. Crowell. "Prolonging the life span." The Scientific Monthly 39.5 (1934): 405-414 and McCay, Carl M., Mary F. Crowell, and Lewis A. Maynard. "The effect of retarded growth upon the length of life span and upon the ultimate body size: one figure." The journal of Nutrition 10.1 (1935): 63-79. [00:06:25] Calorie restriction literature in animals. [00:07:39] Types of rodents studied. [00:08:09] Comparing effect of caloric restriction (CR) on different strains of mice; Study: Liao, Chen‐Yu, et al. "Genetic variation in the murine lifespan response to dietary restriction: from life extension to life shortening." Aging cell 9.1 (2010): 92-95. [00:09:08] Time restricted feeding in animal models. [00:11:51] Calorie restriction vs. malnutrition. [00:12:00] Different levels of calorie restriction. Study: Weindruch, Richard, et al. "The retardation of aging in mice by dietary restriction: longevity, cancer, immunity and lifetime energy intake." The Journal of nutrition 116.4 (1986): 641-654. [00:13:36] Effects of 10% dietary restriction: Richardson, Arlan, et al. "Significant life extension by ten percent dietary restriction." Annals of the New York Academy of Sciences 1363.1 (2016): 11-17. [00:15:09] CALERIE study and resulting Publications. [00:17:56] Analyses of CALERIE data. Studies: Belsky, Daniel W., et al. "Change in the rate of biological aging in response to caloric restriction: CALERIE Biobank Analysis." The Journals of Gerontology: Series A 73.1 (2017): 4-10. and Redman, Leanne M., et al. "Metabolic slowing and reduced oxidative damage with sustained caloric restriction support the rate of living and oxidative damage theories of aging." Cell metabolism 27.4 (2018): 805-815. [00:19:21] Dietary restriction and oxidative stress; Study: Walsh, Michael E., Yun Shi, and Holly Van Remmen. "The effects of dietary restriction on oxidative stress in rodents." Free Radical Biology and Medicine 66 (2014): 88-99. [00:20:29] Podcast: How Oxidative Stress Impacts Performance and Healthspan, with Megan Roberts. [00:20:40] Effects of CR on reactive oxidative species production; Study: Ramsey, Jon J., Mary-Ellen Harper, and Richard Weindruch. "Restriction of energy intake, energy expenditure, and aging." Free Radical Biology and Medicine 29.10 (2000): 946-968. [00:20:59] Effects of fasting on the liver; Study: Salin, Karine, et al. "Decreased mitochondrial metabolic requirements in fasting animals carry an oxidative cost." Functional Ecology (2018). [00:21:56] Control of food intake: Do animal models accurately reflect human behavior? [00:25:06] Enriched environment; Study: McMurphy, Travis, et al. "Implementation of environmental enrichment after middle age pr