Aging & Longevity Research

The Science of Blood and Aging

One of the most compelling discoveries in aging research over the past two decades is that the blood itself carries signals that either promote or inhibit tissue regeneration. This finding emerged from heterochronic parabiosis experiments — where the circulatory systems of young and old animals are surgically connected.

When old animals share blood with young animals, their tissues show remarkable rejuvenation: improved muscle repair, enhanced neurogenesis, reduced neuroinflammation, better liver function, and restored stem cell activity. Critically, the reverse is also true — young animals connected to old ones show accelerated aging.

This research has led to a profound question: Is it possible to achieve similar benefits in humans by modifying the blood’s composition?

Key Research: The Conboy Laboratory

The Plasma Dilution Discovery

In 2020, researchers at UC Berkeley led by Irina and Michael Conboy published a landmark study that shifted the field. Rather than requiring young blood (which raises ethical and practical concerns), they demonstrated that simply diluting old plasma with saline and albumin — without adding any young blood factors — produced rejuvenation effects comparable to young blood exposure.

Their findings showed that neutral blood exchange (NBE) in aged mice:

• Improved muscle repair and stem cell function
• Enhanced neurogenesis (new brain cell growth) and reduced neuroinflammation
• Improved liver function with reduced adiposity and fibrosis
• Lowered inflammatory markers across multiple tissues

The Critical Insight

The Conboy research suggests that aging is partly driven by accumulated pro-aging factors in old blood plasma rather than merely the absence of youthful factors. Removing these inhibitory, pro-inflammatory, and pro-fibrotic factors through plasma exchange may allow the body’s own regenerative capacity to function more effectively.

This is mechanistically equivalent to therapeutic plasma exchange — removing old plasma and replacing it with albumin solution.

What Accumulates in Aging Plasma

Research has identified several categories of age-related plasma changes:

Pro-inflammatory Factors

• Elevated cytokines — IL-6, TNF-alpha, IL-1beta (the “inflammaging” profile)
• Senescence-associated secretory phenotype (SASP) factors — Secreted by senescent cells, these circulating proteins promote inflammation and inhibit tissue repair
• C-reactive protein (CRP) — Chronic low-grade inflammation marker that increases with age

Pro-fibrotic and Inhibitory Signals

• TGF-beta — Elevated with age; inhibits stem cell activation and promotes tissue fibrosis
• CCL11 (eotaxin) — Increases with age; shown to impair neurogenesis and cognitive function
• Beta-2 microglobulin (B2M) — Accumulates with age; impairs hippocampal function

Damaged Proteins and Metabolites

• Advanced glycation end products (AGEs) — Proteins damaged by sugar crosslinking
• Oxidized lipoproteins — Contributing to vascular aging
• Misfolded protein aggregates — Including amyloid fragments

How TPE Relates to Longevity Research

Therapeutic plasma exchange is the clinical procedure most closely analogous to the neutral blood exchange performed in the Conboy experiments:

1. Plasma removal — A volume of plasma is separated from blood cells and discarded
2. Albumin replacement — Clean 5% albumin solution replaces the removed plasma
3. Net effect — Dilution of all circulating plasma proteins, including pro-aging factors, inflammatory mediators, and accumulated waste

A single standard TPE exchange removes approximately 60-70% of circulating plasma proteins, directly reducing the concentration of age-associated inflammatory and inhibitory factors.

Current Evidence in Humans

What We Know

• TPE in human patients safely reduces measurable inflammatory markers (CRP, IL-6)
• The AMBAR trial (for Alzheimer’s) demonstrated that repeated plasma exchange with albumin replacement produced cognitive benefits in elderly patients
• A 2025 randomized placebo-controlled trial (Fuentealba et al.) in 42 healthy adults over age 50 showed that biweekly TPE (with or without IVIG) and monthly TPE produced measurable multi-omics changes — including shifts in DNA methylation, proteomics, and metabolomics — consistent with biological age rejuvenation compared to placebo, with the biweekly TPE + IVIG regimen proving most effective across 15 epigenetic clocks (FDR < 0.05)
• Case reports document improvements in inflammatory biomarkers and subjective wellness following TPE in aging-focused protocols
• Plasma proteomics studies confirm that hundreds of proteins change predictably with age, and many are removable by plasma exchange

What Remains Under Investigation

• Whether TPE-induced plasma dilution produces lasting tissue rejuvenation in humans as observed in mice
• Optimal frequency and volume of exchanges for longevity-oriented protocols
• Which specific biomarkers best predict and track response
• Long-term safety and benefit of repeated exchanges in otherwise healthy individuals
• Whether epigenetic age clocks (Horvath, GrimAge) change following plasma exchange protocols

Biomarkers of Interest

For individuals pursuing longevity-oriented plasma exchange, several measurable markers may be tracked:

• Epigenetic clocks — DNA methylation-based biological age estimates (GrimAge, DunedinPACE)
• Inflammatory markers — hs-CRP, IL-6, TNF-alpha, fibrinogen
• Proteomics panels — Comprehensive plasma protein profiling (e.g., SomaLogic platform)
• Functional measures — Grip strength, cognitive testing, VO2max, walking speed
• Organ-specific markers — GFR (kidney), liver function, HbA1c, lipid panels

What This Is — and What It Is Not

This IS:

• An emerging area of legitimate scientific research published in peer-reviewed journals (Nature, Science, Nature Medicine, Aging)
• A mechanistically rational application of an existing FDA-approved procedure (TPE)
• An individualized discussion between physician and patient about potential benefits and unknowns

This IS NOT:

• An FDA-approved treatment for aging
• A guaranteed anti-aging intervention
• “Young blood transfusion” (no young donor blood is used — only albumin replacement)
• A substitute for established longevity practices (exercise, nutrition, sleep, stress management)

Our Approach at Plasma Life Center

Our board-certified physician will evaluate your situation thoroughly and you will make an informed decision together, based on the current state of research and your individual health goals.

Next Steps

If you are interested in discussing the science of plasma exchange in the context of biological aging and want to understand whether it may be appropriate for you, request a consultation. Come prepared with questions — this is a conversation about emerging science, and informed decision-making requires transparent dialogue about both promise and uncertainty.