Restore Youthfulness & Vitality to the Aging Brain & Body | Dr. Tony Wyss-Coray

KEYPOINTS

• 01

  Young blood can rejuvenate old tissues in mice

  Wyss-Coray, a Stanford neurology professor, describes parabiosis, in which an old and a young mouse are surgically joined so their blood mixes. His colleague Tom Rando showed that young circulation restored old muscle's ability to regenerate. In their joint brain studies, old mice exposed to young blood reactivated brain stem cells, had less inflammation, showed more neural activity and, most importantly, had better memory.

• 02

  Blood is a window into how old you are

  While searching for blood signatures of Alzheimer's disease, his lab found the biggest differences in blood proteins were between young and old people. Labs can now measure about 11,000 proteins in a drop of blood, and some come from specific organs. Joining these protein measurements with large cohorts followed for decades lets researchers build 'clocks' for individual organs.

• 03

  Organs age at different rates, and the gap predicts disease

  For most people, organ ages roughly match their actual age. When one organ's estimated age runs ahead of the person's age (an 'age gap'), it strongly predicts disease in that organ. A fast-aging heart predicts heart disease, kidney predicts kidney disease and brain predicts Alzheimer's. He co-founded Vero Biosciences to offer this kind of profiling, combined with clinical and wearable data, so that fast-aging organs can be caught early.

• 04

  Old blood both adds harmful factors and loses helpful ones

  With age, inflammatory proteins rise. Knocking them out or neutralizing them improved cognition in old mice. Young blood also supplies pro-growth factors, such as GDF11, IGF-1 and Klotho, that help maintain stem cells. The challenge is finding the smallest set of factors that matters; Wyss-Coray thinks a drug might emerge in 5–10 years.

• 05

  Exercise benefits travel through the blood

  Blood from exercised young mice improved the brains of sedentary mice. His former trainee Saul Villeda found that exercised blood had an even stronger effect in old mice. Both labs traced part of the effect to factors released by the liver. Wyss-Coray's lab identified clusterin (apolipoprotein J), a complement-pathway protein, and found that injecting a synthetic version mimicked some of the benefits.

• 06

  Plasma-based treatments look promising but aren't proven

  His company Alkahest showed that young human blood had similar effects in mice, then worked with plasma maker Grifols to test fractions of pooled donor plasma in small Alzheimer's and Parkinson's trials, with promising results. A blinded, placebo-controlled Grifols trial in about 500 Alzheimer's patients that removed their plasma and replaced it with albumin showed significant benefits. A large definitive trial is still needed for FDA approval.

• 07

  No supplement has been shown to extend human lifespan

  Asked about NAD boosters like NMN, Wyss-Coray says no intervention has been validated to extend human lifespan; only exercise and diet have proven benefits. NMN supplements do raise blood levels. A Singapore researcher testing 10 NMN products found many didn't contain what the label said. Huberman takes NMN for a perceived energy boost but doesn't expect it to lengthen his life.

• 08

  Fasting evidence in humans is weak

  Calorie restriction extends life in worms and mice, partly by lowering inflammation and oxidative damage and improving energy use and cellular cleanup. But there's no agreed definition of intermittent fasting, the field is 'a mess,' some monkey studies suggest harm (such as worse kidney function), and no clinical study shows a clear benefit in humans.