Can diets reverse or delay aging?

 Studies from the early 1990s that analyzed the impact of reduced food intake on life span in rats indicated delayed development and increased adult life span in such animals. Other works by Walford, Masoro, and Weindruch made the concept of caloric restriction (CR) an important factor for anti-aging intervention in both mice and rats. These studies also suggest that along with an increase in life span, CR reduces the disease burden and slows down many functional declines of old age.

The CR definition in such studies is "reduced caloric intake in the absence of malnutrition." However, the exact mechanism of food limitation, degree of restriction, and timing of initiation varied. Similar studies also took place in invertebrate models, but due to different culture conditions across species, these interventions were termed "dietary restriction" (DR). These studies helped identify a highly conserved growth-promoting and nutrient-sensing network capable of regulating biological aging in several different organisms. Some of the important proteins of this network involved the mechanistic target of adenosine 5′-monophosphate (AMP)–activated protein kinase (AMPK), rapamycin (mTOR), insulin and insulin-like growth factor 1 (IGF-1)–like receptor, nicotinamide adenine dinucleotide (NAD)– dependent sirtuin deacetylases, as well as FOXO-family transcription factors.

Following this, research focused on identifying small molecules that could mirror the effects of CR on health and lifespan without reducing food consumption. A few "CR mimetics" included the antidiabetes drug metformin, the mTOR inhibitor rapamycin, the intestinal a-glucosidase inhibitor acarbose, sirtuin-activating compounds, and the glycolytic inhibitor 2-deoxyglucose. However, most of them have been unable to match CR's health and lifespan benefits.

A new review published in the journal Science aimed to summarize the commonly studied anti-aging dietary interventions and their impact on human health and longevity.

Rise of anti-aging diets

Anti-aging diets can be categorized into two groups; CR and isocaloric nutrient restriction. Diets such as fasting-mimicking diets (FMDs), intermittent fasting (IF), and ketogenic diets (KDs) fall under the CR group, while protein restriction (PR), time-restricted feeding (TRF), and amino acid restriction fall under the isocaloric nutrient restriction group.

Source: News-Medical