Blood Test for Longevity

Scott LaFee
Tue, 14 Apr 2026 21:00:00 -0700
Lifestyle

You can do all the right things to live long and well — eat right, exercise, refrain from smoking, etc. — but it's still pretty much a guessing game whether such behaviors will add up to measurably added years.

But a new, experimental blood test developed by researchers at Duke Health and the University of Minnesota might someday provide empirical clues — at least in the sense of short-term survival.

The scientists found that measuring levels of small RNA molecules called Piwi-interacting RNAs accurately predicted whether older adults are likely to survive at least two more years.
Updated: Wed Apr 15, 2026

You can do all the right things to live long and well — eat right, exercise, refrain from smoking, etc. — but it's still pretty much a guessing game whether such behaviors will add up to measurably added years.

But a new, experimental blood test developed by researchers at Duke Health and the University of Minnesota might someday provide empirical clues — at least in the sense of short-term survival.

The scientists found that measuring levels of small RNA molecules called Piwi-interacting RNAs accurately predicted whether older adults are likely to survive at least two more years.

"The combination of just a few piRNAs was the strongest predictor of two-year survival in older adults — stronger than age, lifestyle habits or any other health measures we examined," said study author Virginia Byers Kraus at Duke University School of Medicine.

PiRNAs help regulate development, regeneration and the immune system. Researchers measured piRNA levels in adults age 71 and older and found that lower levels of certain piRNAs correlated to longer survival. Advanced statistical modeling revealed that a group of six piRNAs alone predicted two-year survival with accuracy as high as 86%.

Next steps include studying whether treatments, lifestyle changes or medications, such as GLP-1-based therapies, alter piRNA levels. Researchers will also compare piRNA levels in blood with levels inside tissues to better understand how these molecules function.

"These small RNAs are like micromanagers in the body, helping control many processes that affect health and aging," said Kraus.

Body of Knowledge

Human lips are reddish in color because of the great concentration of tiny capillaries or blood vessels just below the skin. The blood in these capillaries is normally highly oxygenated and thus quite red. People who are anemic or who have lost a lot of blood often have pale lips. Similarly, lips turn "blue" in very cold weather because the capillaries constrict, reducing the flow of bright red, oxygenated blood.

Doc Talk

Claudication: Limping caused by a reduction in blood supply to the legs

Mania of the week

Hexometromania: Obsession with writing in hexameter — Homer, Virgil and Ovid were clearly addicted

Life in Big Macs

One hour of walking briskly while carrying something weighing less than 25 pounds burns 306 calories (based on a 150-pound person), the equivalent of 0.4 Big Macs. FYI, it takes approximately 50 Big Macs to equal 25 pounds. If you ate all 50 Big Macs, you'd have to walk briskly for more than 100 hours, or more than 4 days and nights, to burn them all off.

Best Medicine

The biggest drawback to fasting for seven days is that it makes one weak.

Hypochondriac's Guide

Reward deficiency syndrome is a concept introduced in 1996 by American pharmacologist Kenneth Blum, who connected an inborn chemical imbalance that alters neural signaling in the brain's reward process, resulting in addictive, obsessive or compulsive behaviors. The syndrome isn't officially or medically recognized, but we all recognize someone who has it.

Observation

"The bus scares me. Way too many gross people on the bus. Sixty-five people on the bus and I was the last one on. I felt like calling 'Unsolved Mysteries.' 'Yeah, I found everybody.'" — American comedian Kathleen Madigan (b. 1965)

Medical History

This week in 1625, the word "microscope" was coined as a suggested term for the device in a letter written by Johannes Faber of Bamberg of Germany to Federico Cesi, Duke of Acquasparta and founder of Italy's Accademia dei Lincei (Academy of the Lynx).

The academy, possibly the world's first scientific society, took Lynx for its name after the animal due to its reputation of having exceptional vision.

Ig Nobel Apprised

In 2005, the Ig Nobel Prize in medicine went to Gregg A. Miller of Oak Grove, Missouri, for inventing Neuticles — artificial replacement testicles for neutered dogs. They came in multiple sizes and degrees of firmness.

Sum Body

Fourteen symptoms that should prompt medical attention:

— Diarrhea lasting more than three days

— Headache that won't go away or gets worse

— Heartburn that doesn't go away for several weeks

— Back pain that doesn't go away within a few days, especially if it radiates down the legs and/or comes with weakness, numbness, redness, swelling or a fever

— A bump to the head, followed by symptoms such as confusion, fogginess, sleep issues, nausea or mood changes

— Menstrual bleeding much longer or heavier than usual, or bleeding between periods

— Severe or disabling menstrual cramps

— Sadness or depression that doesn't go away

— Thoughts of harming oneself or others

— Social withdrawal

— Extreme emotional highs and lows, or excessive anxiety, fear or worry

— Skin changes, like a new or changing mole

— Irregular or rapid heartbeat

— Concerning symptoms after surgery or starting a new medication

(Note: This is not an exhaustive list. You should see a doctor for any concerning symptoms that are chronic, appear suddenly or don't go away on their own.)

Last Words

"Oh well, whatever." — Lola S. Holt (1923-2004)