Vitae Health
TopicsArticlesNewsletterAbout
Ask VitaSign In
Topics/Longevity
09 — Biology

Longevity.
The science of aging well

Aging is not a passive process — it is driven by specific, measurable biological mechanisms. Telomere shortening limits cell division. Senescent cells accumulate and secrete inflammatory cytokines (SASP). NAD+ declines with age, impairing sirtuin activity and DNA repair. Mitochondrial function degrades. Autophagy — the cellular recycling system — slows down. Each of these mechanisms is a potential intervention point. Longevity science is not about living forever — it is about extending the years you spend healthy, functional, and free of chronic disease.

aging biologytelomeresNAD+autophagysenescent cellsmTORsirtuins
Evidence

What the research actually shows.

Peer-reviewed findings on longevity — not opinions, not trends.

01

NAD+ levels decline by approximately 50% between ages 40 and 60. NAD+ is required for sirtuin activation (DNA repair, mitochondrial function) and PARP activity (single-strand DNA break repair). This decline is considered a central driver of age-related metabolic dysfunction.

02

Autophagy — the process by which cells digest and recycle damaged components — declines significantly with age. Fasting for 24-48 hours is one of the most potent known triggers of autophagy in humans, via AMPK activation and mTOR inhibition.

03

Senescent cells make up less than 1% of total cells but drive outsized damage through the senescence-associated secretory phenotype (SASP) — a cocktail of inflammatory cytokines, proteases, and growth factors that damages neighboring healthy cells.

04

VO2 max declines approximately 10% per decade after age 30 in sedentary individuals but only 5% per decade in those who maintain vigorous exercise. The difference between the lowest and highest fitness quintile in mortality risk is larger than the difference between smokers and non-smokers.

From the Research

What 6 peer-reviewed studies show.

01

Pelvic floor muscle training may be an effective treatment for postmenopausal urinary incontinence, but more research is needed to compare it with other treatments.

Meta-AnalysisArchivio italiano di urologia, andrologia : organo ufficiale [di] Societa italiana di ecografia urologica e nefrologica · 2023Bapir R., Bhatti K. et al.PMID 37791545 ↗
02

Physical activity is associated with increased muscle strength and muscle power in older adults.

Meta-AnalysisAgeing research reviews · 2021Ramsey K., Rojer A. et al.PMID 33607291 ↗
Biology Intelligence

Have a question about longevity?

Ask our biology AI — answers grounded in peer-reviewed research.

Ask a question →
Methodology

Every article on longevity is built on systematic reviews, meta-analyses, and RCTs from PubMed. Evidence grade is always disclosed.

Evidence hierarchy →
Ask a question

Biology Intelligence retrieves answers from our verified study database. Ask anything about longevity.

Open Biology Intelligence →
Connected Systems

Longevity connects to everything.

All topics →
01
Movement

The medicine hiding in plain sight

02
Nutrition

What your cells actually need

03
Stress

How chronic pressure reshapes your brain and body

04
Inflammation

The root of modern disease

The Weekly Dose

One study.
Every week.

A single peer-reviewed study broken down every week — the mechanism, the evidence grade, and what it means for you.

Subscribe free

Or follow @vitaehealthco for daily posts

← StressAll TopicsMental Health →
Vitae Health

We dig into the research so you don't have to. Every claim traced to a study. No products. No agenda.

@vitaehealthco
Topics
SleepGut HealthNutritionHormonesCircadian BiologyAll Topics
More
ToxinsStressLongevityMental HealthLightInflammation
Company
AboutEvidence StandardMyth GraveyardResearch LibraryArticlesNewsletterFree GuidesPrivacy
© 2026 Vitae Health. All content is educational and not medical advice.Evidence-based. Always cited. Zero products.
03

Hydrolyzed collagen supplementation can improve skin hydration and elasticity.

Effect: HC supplementation significantly improved skin hydration (Z = 4.94, p < 0.00001) and elasticity (Z = 4.49, p < 0.00001)

Meta-AnalysisNutrients · 2023Pu S., Huang Y. et al.PMID 37432180 ↗
04

Older adults with a history of falls are more likely to have certain risk factors, such as older age and lower physical activity.

Meta-AnalysisFrontiers in public health · 2022Xu Q., Ou X. et al.PMID 36324472 ↗
05

Resistance training and caloric restriction can be effective for reducing body fat percentage in individuals with overweight/obesity.

Effect: ES=−0.34 (95% CI −0.43 to −0.25) for body fat percentage

Meta-AnalysisObesity reviews : an official journal of the International Association for the Study of Obesity · 2022Lopez P., Taaffe D. et al.PMID 35191588 ↗
06

Patients with cardiovascular diseases have a higher prevalence of sarcopenia compared to the general population.

Effect: OR 2.14 (95% CI 1.83–2.51)

Meta-AnalysisJournal of cachexia, sarcopenia and muscle · 2023Zuo X., Li X. et al.PMID 37002802 ↗