THE EVIDENCE DESK
What the research actually shows.
Plain-language reviews of the studies behind longevity products: what is well supported, what is promising but thin, and what isn’t worth your money.
Ratings run Strong, Moderate, Mixed, Weak and Not supported. They describe the evidence for a claimed benefit, not the quality of any product. Read the grading method.
EVIDENCE REVIEWS
What the evidence says, category by category
Air quality
Do air purifiers work? What the evidence shows for health
The evidence is strong for the narrow claim: in randomized trials in real homes, HEPA purifiers cut indoor fine particles (PM2.5) by about half or more.
Strong evidenceBlood, biological-age & glucose testing
Is a CGM worth it if you don’t have diabetes? What the evidence shows
We found no trial showing that wearing a CGM improves health or prevents disease in people without diabetes. Recent reviews say the evidence in this group lacks consistency and quality.
Not supported by evidenceCold plunges & contrast therapy
Do cold plunges work? What the evidence shows
In active people, cold-water immersion eases soreness and helps them feel recovered the day after hard exercise. But routine use after strength training appears to blunt gains in strength and muscle size.
Mixed evidenceRed-light therapy
Does red light therapy work? The evidence for skin, hair, muscles, joints and aging
Results depend on the use. The best evidence is for pattern hair loss and knee pain, and both come with catches. For wrinkles, acne and exercise recovery, the trials are small, varied or inconclusive.
Mixed evidenceSaunas
Are saunas good for you? What the evidence shows and what it doesn’t
In a long-running Finnish cohort, men who used a traditional sauna four to seven times a week had lower rates of cardiovascular death, death from any cause and dementia than once-a-week users.
Moderate evidenceSleep & bedding
Do cooling mattress pads, sleep masks and sheets help you sleep? What the evidence shows
Falling asleep is closely tied to the body shedding heat through the skin, but evidence for the products built on that link is thin. Studies of a temperature-controlled mattress cover are small and lasted about a week.
Weak evidenceThird-party-tested supplements
Do creatine, fish oil, vitamin D and magnesium work? What trials show in healthy adults
The evidence differs by supplement. Creatine with resistance training has the most consistent support: modest gains in lean mass and strength. In large trials of healthy older adults, routine fish oil and vitamin D didn’t prevent heart events or cancer.
Mixed evidenceBlood, biological-age & glucose testing
Are longevity blood tests and biological-age clocks worth it? What the evidence supports
Large longevity panels and biological-age clocks aren’t supported as a way to improve health. Trials of general health checks found little or no effect on deaths, and we found no trial showing that a large panel or clock score helps healthy adults.
Not supported by evidenceWater filtration
Do water filters work? What certification proves and what it means for your health
The evidence is strong for the narrow claim: a filter certified for a contaminant reduces that contaminant. Each claim covers one contaminant, and today’s PFAS test target of 20 ppt is well above EPA’s 4.0 ppt limits for PFOA and PFOS.
Strong evidenceSleep & recovery wearables
How accurate are sleep trackers? What the validation studies show
Consumer rings and watches catch more than 90% of sleep in lab studies, but they miss much of the time you spend awake and agree only fairly to moderately on sleep stages.
Moderate evidenceWORTH IT
Worth it
WORTH IT
Are home blood pressure monitors worth it? Yes, with a validated cuff that fits
Worth it if you have, or may have, high blood pressure. Use a validated upper-arm cuff in the right size, and take readings the same careful way each time.
Moderate evidencePARTLY WORTH IT
Are smart scales worth it? Yes for weight trends, not for body-fat or metabolic-age readings
Partly worth it. A scale that makes regular weighing easy is a reasonable tool inside a weight-management plan, but advice to weigh yourself with nothing else hasn’t been shown to work.
Moderate evidenceWORTH IT
Is home exercise equipment worth it? Yes, if you’ll use it every week
Large cohort studies consistently link muscle-strengthening activity and higher aerobic fitness with lower death rates, but the link is observational.
Moderate evidenceWORTH IT
Are walking pads and under-desk treadmills worth it? Yes, with caveats
Worth it, with caveats, if it gets you walking on days you’d otherwise sit. The rating is Moderate because the evidence is good but indirect.
Moderate evidenceNOT WORTH IT
Not worth the money
BLUE-LIGHT GLASSES
Do blue-light glasses work? What the Cochrane review and eye doctors say
A 2023 Cochrane review of 17 small, short randomized trials found that blue-light filtering lenses may make little or no difference to eye strain from computer use.
Not supported by evidenceGROUNDING AND EARTHING
Does grounding work? What the earthing mat and sheet studies show
The case for grounding mats and sheets rests on a handful of small, short studies. In the two blinded trials we could read directly, self-reported soreness, sleep quality and stress didn’t differ between real and sham groups.
Weak evidenceHYDROGEN WATER
Is hydrogen water worth it? Small trials, small effects, no proof of slower aging
The headline claims for hydrogen water, from anti-aging to antioxidant protection, haven’t been shown in people. Pooled trials find no gain in aerobic fitness and no drop in a key oxidative-stress marker.
Not supported by evidenceNMN SUPPLEMENTS
Does NMN work? Blood NAD+ rises, but anti-aging benefits are unproven
NMN reliably raises NAD+ in blood. But small, short trials in mostly healthy adults show no consistent benefit for blood sugar, cholesterol, muscle or physical function.
Not supported by evidencePEMF MATS AND DEVICES
Do PEMF mats work? Uncertain pain relief, no evidence for longevity
The evidence doesn’t support PEMF for wellness or longevity. No human trial we found measured lifespan, biological aging or cellular energy.
Not supported by evidenceSIT-STAND DESKS
Are standing desks worth it? Not a proven heart-health fix, but useful for some
Standing more is not a proven heart-health fix: in a large UK study, standing time wasn’t linked to lower cardiovascular risk. Sit-stand desks cut sitting at work, mostly by replacing it with standing.
Not supported by evidencePOLICY