Research Digest
Research Library
Peer-reviewed papers from top journals, summarized and graded by evidence strength. Updated Mon, Wed & Fri.
May 10–16, 2026
2 studiesBlood NAD+ Levels Stay Flat With Age, Challenging Popular Aging Theory
One of the most repeated ideas in longevity is that NAD+ declines as we age, a story that helped make NR and NMN household names in the space. This large, carefully controlled study takes a closer look. Across seven independent cohorts and more than 300 people, researchers found that whole-blood NAD+ levels stayed remarkably stable with age, and didn't shift meaningfully in response to exercise, protein-rich diets, or multimodal lifestyle interventions in older adults. Importantly, NR supplementation did raise blood NAD+ as expected, confirming that the supplements work pharmacologically, the question is just whether blood NAD+ is the right thing to be measuring in the first place.
Just 5,700 Daily Steps Cut Death Risk By 13% In Older Adults
Looking at dozens of studies with over 367,000 older adults, regular walking was tied to lower risk of death, disease, and cognitive decline. Each extra 1,000 daily steps was linked to a 13% drop in death from any cause. Walking pace did not change the benefit, so slow walks counted too.
May 3–9, 2026
2 studiesLong-Lived Genes May Give Grandkids a Healthier Start in Life
Grandchildren of Danish families known for exceptional longevity had about half the risk of dying in infancy compared to the general population. They also showed better health markers at birth. But by the great-grandchildren generation, this advantage faded considerably, hinting that the protective effect dilutes over time.
Exercise Linked to Younger Biological Age, But Effect Is Modest
Pulling together 44 studies on nearly 145,000 people, researchers found that more physical activity is tied to a younger biological age, but only on certain epigenetic clocks. The effect showed up clearly on GrimAge and Horvath clocks, but not on Hannum or PhenoAge. The size of the benefit was small, and most data came from snapshot studies, so we can't say exercise actually causes the slowdown yet.
Apr 26 – May 2, 2026
2 studiesStress Response Trade-Off: Less ATF4 Activity May Extend Lifespan in Flies
Scientists used to think turning on the body's stress response made organisms live longer. But in fruit flies, the opposite was true. When researchers dialed down a key stress pathway called GCN2-ATF4, flies lived longer. Cranking it up shortened their lives. This complicates the popular idea that all forms of cellular stress activation are good for aging.
How Polyphenols From Tea, Berries, and Curcumin May Slow Aging Pathways
This review looks at how common plant compounds like resveratrol, EGCG from green tea, curcumin, and quercetin may influence aging. They appear to nudge the same pathways targeted by longevity drugs, including AMPK, sirtuins, and mTOR. They also feed gut bacteria that produce urolithin A, a compound linked to better mitochondrial health.
Apr 12–18, 2026
2 studiesCholesterol, Immune Cells, and IGF-1 Emerge as Key Longevity Signals
Researchers combed through massive genetic databases to find what actually drives long life and slower biological aging. Three factors stood out: cholesterol levels, immune cell traits, and IGF-1 (a growth hormone linked to aging). They also flagged 30 genes and several proteins as possible drug targets for future anti-aging therapies.
Quail Bred to Reproduce More Aged Faster, Supporting a Core Theory of Aging
Researchers selectively bred Japanese quail for higher or lower reproductive effort across several generations. By generations five and six, the high-reproduction birds died sooner. The lifespan difference came from faster aging rates, not from being more fragile to begin with. This is some of the cleanest experimental evidence in vertebrates that investing more in reproduction comes at a real cost to longevity.
Mar 29 – Apr 4, 2026
2 studiesMetformin's Anti-Aging Case: Strong Clues but Still No Proof
This review pulls together lab, population, and clinical trial evidence on metformin as a potential aging-slowing drug. At normal doses, metformin seems to flip several key aging switches: boosting cellular cleanup, calming inflammation, and improving energy production. Large population studies link metformin use to lower rates of age-related diseases, even in people without diabetes. However, the review honestly notes that metformin may actually worsen aging in older animals, so the picture is still mixed.
Longevity Protein Klotho May Protect Against Cognitive Decline in Parkinson's
People with Parkinson's disease who carry a specific variant of the klotho gene tended to perform better on executive thinking tasks across two separate groups. In mice engineered to model Parkinson's, boosting klotho levels improved brain function and reduced alpha-synuclein (a toxic protein that builds up in Parkinson's). The cognitive benefits showed up without improving motor symptoms. Lab experiments suggested klotho may work by helping brain cells clear that toxic protein more effectively.
Disclaimer: Research summaries are provided for informational purposes only and do not constitute medical advice. Always consult a qualified healthcare professional before making changes to your health routine.
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