A 2024 primate study investigated effects of an off-patent drug on age-related changes:

“We evaluated geroprotective effects of metformin on adult male cynomolgus monkeys. The study encompassed a comprehensive suite of physiological, imaging, histological, and molecular evaluations, substantiating metformin’s influence on delaying age-related phenotypes at the organismal level.

Results highlighted a significant slowing of aging indicators, notably a roughly 6-year regression in brain aging. Metformin exerts a substantial neuroprotective effect, preserving brain structure and enhancing cognitive ability.

Geroprotective effects on primate neurons were partially mediated by activation of Nrf2, a transcription factor with anti-oxidative capabilities.”

https://www.cell.com/cell/abstract/S0092-8674(24)00914-0 “Metformin decelerates aging clock in male monkeys” (not freely available). Thanks to Dr. Pradeep Reddy for providing a copy.

From this study’s Nrf2 activation findings:

“Metformin treatment resulted in increased nuclear phosphorylated Nrf2, accompanied by up-regulation of Nrf2 target genes like HO-1, NQO-1, SOD3, GPX2, and GPX1, which were generally suppressed and typically down-regulated during human neuron senescence.

Genes pivotal for neuronal function, such as dendrite morphogenesis/extension and synapse assembly (e.g., GSK3B, GRID2, and NRG3), were down-regulated during aging in excitatory neurons (ExN), inhibitory neurons (InN), oligodendrocytes (OL), oligodendrocyte progenitor cells (OPC), microglia, and astrocyte but were restored by metformin treatment. By contrast, pathways that were up-regulated during aging, including activation of the immune response, complement activation, and regulation of the TGF-b receptor signaling pathway, were reset to lower levels by metformin treatment.

We verified that markers associated with brain aging and progression of neurodegenerative diseases were restored by metformin treatment to levels similar to those observed in young monkeys. Additionally, we observed that reduced myelin sheath thickness, a characteristic of aged monkeys, was rebuilt to a younger state following metformin treatment.

These findings align with the levels of nuclear-localized phosphorylated Nrf2, suggesting that Nrf2 pathway activation is a key mechanism in metformin’s role in delaying human neuronal aging and, by extension, brain aging. Consistent with our in vitro findings, Nrf2 pathway activation was also detected across multiple tissues in metformin-treated monkeys, including frontal lobe neurons.

At last count, I’ve curated 250+ papers this decade on cruciferous vegetables, and many of these explored relationships with Nrf2 activation. Basically, eating a clinically-relevant daily dose of 3-day-old cruciferous sprouts and taking off-patent metformin both induce Nrf2 activation effects.

Don’t expect to see many researchers highlighting this equivalency. They’d rather wait another decade to nitpick other studies with not-enough-subjects / not-exactly replicated / other nitpicks before expressing opinions urging caution from their nursing home beds.

But even then, they won’t get their facts straight. For example, a contemporaneous opinion article https://www.nature.com/articles/d41586-024-02938-w “The brain aged more slowly in monkeys given a cheap diabetes drug” attempted to summarize this study, and flubbed two points:

1. The study said: “We conducted a proof-of-concept study involving male cynomolgus monkeys (Macaca fascicularis) aged between 13 and 16 years, roughly equivalent to approximately 40–50 years in humans. Monkeys adhered to this regimen for a period of 1,200 days, approximately 3.3 years, which corresponds to about 10 years in humans.”

The opinion claimed: “Animals took the drug for 40 months, which is equivalent to about 13 years for humans.”

2. The opinion quoted a New York City researcher involved in a separate metformin study and employed at a medical school for:

“Research into metformin and other anti-ageing candidates could one day mean that doctors will be able to focus more on keeping people healthy for as long as possible rather than on treating diseases.”

This statement is a big break from the realities of medical personnel daily actions at least so far this decade, which is when I started to pay close attention:

• Doctors have very little diet and exercise training in medical school. There’s no way they can give health advice. There’s no way that a “keeping people healthy” paradigm will emerge from the current medical system.
• Fixing a disease doesn’t restore a patient’s health. Dr. (PhD) Goodenowe cites several examples in his talks, such as a study that compared colorectal cancer therapy with post-operation patient health.
• If you listen to yesterday’s two-hour-long podcast, the currently injured person in the first hour gave plenty of contrary evidence of doctors’ focuses: behaviors of trying to blame and gaslight the patient, thinly-disguised punitive actions, CYA etc., all of which they will be sued for one day. The doctor in the second hour provided an example of the quoted researcher in her explanation of how doctors higher in the hierarchy either can’t see or can’t admit realities of doctor/patient interactions, and what therapies have actually benefited or harmed a patient.