Longevity & Anti-Ageing

Landmark Cell review of mTORC1 as the master anabolic sensor. mTORC1 is activated by amino acids (leucine is the primary signal), insulin (in response to glucose/carbohydrates), and growth factors — driving muscle protein synthesis, cell growth, and inhibiting autophagy. Chronic mTORC1 activation by nutrient excess is associated with accelerated ageing, cancer, and insulin resistance. Conversely, periodic mTORC1 suppression via fasting or caloric restriction allows autophagy and cellular quality control — the mechanistic basis of intermittent fasting's longevity benefits.

AMPK (AMP-activated protein kinase) is the cellular energy sensor activated by caloric restriction, fasting, exercise, and metformin (the anti-diabetic drug). AMPK activation suppresses mTORC1, activates autophagy and mitochondrial biogenesis, and improves insulin sensitivity. Dietary activators include polyphenols (resveratrol, EGCG), berberine, and caloric restriction. Exercise is the most powerful AMPK activator — providing a mechanism by which physical activity extends healthspan independently of weight loss.

Defining Cell review identifying 9 hallmarks of biological ageing including genomic instability, telomere attrition, epigenetic alterations, mitochondrial dysfunction, cellular senescence, and deregulated nutrient sensing (mTOR, AMPK, sirtuins). Dietary interventions targeting multiple hallmarks simultaneously include caloric restriction (mTOR suppression, autophagy), protein sufficiency (prevents sarcopenia and reduces frailty), omega-3 fatty acids (anti-inflammatory), and polyphenols (AMPK activation, epigenetic modification) — the scientific basis for a longevity-focused dietary pattern.

Prospective cohort study (n=73,744 women; n=43,339 men over 12 years) demonstrating that improving diet quality score by 1 standard deviation over any 12-year period reduced all-cause mortality by 8–17% and CVD mortality by 7–14%. Improvements in Mediterranean diet adherence score were most protective. Crucially, improvement at any age predicted mortality benefit — establishing that dietary change in middle age and later life still substantially extends lifespan.

Measured leukocyte telomere length (a biological ageing biomarker) in 4,676 women from the Nurses Health Study in relation to Mediterranean diet adherence score. Each 1-point increment in Mediterranean diet score corresponded to longer telomeres equivalent to 1.5 years of chronological ageing. Subjects in the highest vs lowest tertile of adherence showed telomere differences corresponding to ~4.5 biological years. Olive oil, fish, nuts, and vegetables were the highest-loading components — consistent with anti-inflammatory and polyphenol-mediated epigenetic effects on telomere maintenance.

Synthesis of dietary and lifestyle patterns across five "Blue Zones" (Okinawa, Sardinia, Nicoya, Icaria, Loma Linda) where centenarian rates are 10× higher than the US average. Common dietary features: predominantly whole-food, plant-based with low but regular animal protein (10–20% of calories); legumes as a daily staple (lentils, soy, fava beans); minimal sugar and processed foods; moderate calorie intake; alcohol only as moderate red wine (Sardinia/Icaria). These communities achieve longevity without caloric restriction per se but through naturally low-energy-density, high-fibre, high-polyphenol diets.

Comprehensive review of caloric restriction effects on human biomarkers. 20–25% caloric restriction for 2+ years reduces: fasting insulin (−40%), IGF-1 (−22%), thyroid hormones (adaptive), inflammatory cytokines (TNF-α, CRP), and oxidative stress markers. CR does not impair muscle mass when protein intake remains ≥1.5 g/kg/day. Practical longevity interventions include: time-restricted eating, periodic 5:2 fasting, and protein cycling (lower protein on rest days, higher on training days) to create intermittent mTOR suppression without sacrificing muscle.

CALERIE Phase 1 RCT (n=48) achieving 25% caloric restriction for 6 months. Body weight fell 10.4%, fasting insulin −40%, resting metabolic rate fell less than expected (adaption), core body temperature fell (longevity biomarker in animal models). Importantly, this RCT demonstrated that moderate CR is feasible in free-living humans and produces metabolic signatures associated with extended lifespan — without requiring extreme restriction or protein deficiency.

Defines "anabolic resistance" — the blunted muscle protein synthesis (MPS) response to amino acids and exercise in older adults (≥60 years). Anabolic resistance means older adults require ~40g protein per meal (vs 20–25g in young adults) to achieve the same MPS stimulation. Mechanisms: impaired mTORC1/S6K1 signalling, reduced leucine sensitivity, greater splanchnic amino acid extraction, and low-grade systemic inflammation. Resistance training partially reverses anabolic resistance, reinforcing the synergistic importance of weight training + high-protein meals in ageing populations.

Systematic review specifically addressing protein requirements in master athletes (≥35 years). Concluded that masters athletes require 1.6–2.4 g protein/kg/day — higher than young adult recommendations — with individual meals targeting ≥40g leucine-rich protein for maximal MPS. Post-exercise protein timing window is more critical in masters athletes (blunted late-phase response) and pre-sleep protein (40g casein) is uniquely effective at countering overnight catabolic elevation. This informs the platform's age-adjusted leucine and protein distribution thresholds.

ESCEO expert group systematic review of nutritional strategies to prevent sarcopenia (age-related muscle loss, affecting 10–15% of adults over 60). Strongest evidence supports: daily protein ≥1.0–1.2 g/kg (ESPEN recommendation) ideally 1.5–2.0 g/kg with exercise; leucine enrichment of protein meals; vitamin D ≥800 IU/day combined with calcium; and omega-3 supplementation (improving muscle anabolic sensitivity). Sarcopenia increases fall risk 3×, mortality 2×, and healthcare costs substantially — making protein-adequate ageing a critical public health issue.