Answers
What the studies say about the questions people ask most, each graded A to D for how strong the evidence is. For anything else, ask the evidence yourself.
Supplements
- CDoes creatine help memory in older adults?Creatine may give older adults a small memory boost, but the trials vary a lot and the biggest one found little effect. We don't know yet if it's real.
- CDoes magnesium improve sleep?Magnesium may help some adults fall asleep a little sooner, but the trials are small and inconsistent. We don't yet know if it works for most people.
- BDo NMN supplements raise NAD+ in people?Yes. In several small trials, NMN taken by mouth raised NAD levels in blood, and higher doses raised it more. The size of the rise is uncertain.
- BDoes fish oil prevent heart attacks?Fish oil capsules didn't clearly prevent heart attacks in most people. The one big exception is a high-dose, purified EPA drug, which cut heart events in high-risk people on statins.
- ADoes vitamin D prevent fractures?No. In healthy adults living at home, vitamin D alone did not lower the chance of a broken bone, even at 2,000 IU a day.
- CDoes omega-3 slow cognitive decline?Omega-3 supplements have not clearly slowed cognitive decline. The largest trial found no effect over 3 years, while smaller, shorter trials show small memory gains in some healthy older adults.
- BDoes curcumin help joint pain?Yes, curcumin eased joint pain a modest amount in people with arthritis, mostly knee osteoarthritis, in trials lasting 4 to 36 weeks. The quality of many trials was low.
- CDoes ashwagandha lower cortisol?Yes, in most small trials ashwagandha lowered cortisol, the main stress hormone, more than a dummy pill did. Results vary a lot between trials, and one found no difference.
- DDoes taurine slow aging in humans?We don't know yet whether taurine slows aging in people. It extended lifespan about 10% in mice, but no human trial has tested aging or lifespan.
- DDoes spermidine slow aging in humans?We don't know yet. Spermidine hasn't been tested for slowing aging in people. Small trials looked at memory and blood markers, with mixed results.
- CDoes urolithin A improve muscle in older adults?Urolithin A may add a little muscle strength and endurance in middle-aged and older adults. Walking distance and peak power didn't clearly improve, and we don't know yet whether it matters in daily life.
- DDoes fisetin clear senescent cells in people?We don't know yet whether fisetin clears senescent cells in people. Cleared cells have been shown only in cells and mice, and no human trial has shown it.
- DDoes resveratrol extend lifespan in humans?We don't know yet. No study has shown that resveratrol helps people live longer, and the evidence for longer life comes from animals, with mixed results.
Drugs
- CIs rapamycin safe for healthy people?In small, short trials, low-dose rapamycin caused few serious problems in healthy adults. Long-term safety for healthy people is unknown, and the drug is approved only for transplant and certain diseases.
- CDoes metformin slow aging without diabetes?We don't know yet whether metformin slows aging in people without diabetes. The longest trial found no drop in deaths, and a recent trial in frail older adults found no gain in walking speed.
- ADoes low-dose aspirin still make sense?For healthy people with no heart disease, low-dose aspirin now brings little net benefit and is not advised from age 60. For people who already had a heart attack or stroke, it still clearly helps.
- ADo statins raise the risk of diabetes?Yes. Statins raise the chance of a new diabetes diagnosis a little, by about 10% at usual doses and more at high doses. The heart benefits are larger.
- BDo GLP-1 drugs cause muscle loss?Yes, GLP-1 drugs reduce lean mass along with fat, about a quarter of the weight lost. Whether that means weaker muscles in daily life hasn't been tested well.
- BWhat is known about SGLT2 drugs and aging?SGLT2 drugs lower the risk of heart death and heart failure hospital stays, including in older adults with heart failure or diabetes. Whether they slow aging itself is unknown.
Peptides
- DIs there human evidence for BPC-157?Yes, but very little: three small studies with 30 people in all, none with a comparison group. Most people reported feeling better, though these studies can't show the peptide caused it.
- DIs there human evidence for TB-500?No. Human trials tested full thymosin beta-4 gel on leg ulcers, not TB-500 injections, and no human data show TB-500 heals injuries. Its safety in people is unknown.
- DDoes epitalon extend lifespan in humans?We don't know yet. No study has tested whether epitalon extends human lifespan, and the lifespan claims rest on animal and cell research.
Exercise
- BDoes strength training lower the risk of death?Yes. People who lift weights or do other strength training have about 15% to 20% lower risk of death than people who don't. The best gains come at about an hour a week.
- BHow much does zone 2 training raise VO2 max?Moderate-intensity endurance training raised VO2 max by about 5 mL/kg/min in healthy young and middle-aged adults, roughly a 10% gain. Trials haven't tested zone 2 training on its own.
- BHow many steps a day lower mortality?Risk of death falls steadily as daily steps rise, up to about 6,000 to 8,000 steps for adults over 60 and 8,000 to 10,000 for younger adults. Gains flatten after that.
- CIs high-intensity interval training safe after 60?High-intensity interval training looks safe for healthy older adults in small, supervised trials, with no serious problems reported. Too few trials tracked harms to rule out rare ones.
- CDoes creatine increase muscle strength in older adults?Yes, a little. In older adults doing resistance training, creatine added a small strength gain beyond training alone. Some trials found no extra gain, and results for those not training are unknown.
- BDoes more physical activity lower the risk of dying early?Yes. People who are more active die early less often, and the biggest gain comes from moving from doing nothing to doing a little.
Nutrition
- BDoes intermittent fasting beat calorie cutting?Mostly no. Intermittent fasting and cutting calories every day lead to about the same weight loss. Alternate-day fasting may edge ahead by roughly 1 kg in shorter trials.
- CHow much protein do older adults need?Most healthy older adults do well on about 1.0 to 1.2 g of protein per kg of body weight a day, and 1.2 to 1.5 g if ill or active. That is above the standard 0.8 g.
- CDoes a Mediterranean diet extend life?People who eat a Mediterranean-style diet more closely tend to live longer, but this comes from observational studies. Trials haven't shown the diet itself extends life.
- DIs moderate drinking good for the heart?We don't know yet. Older studies link light drinking to fewer heart problems, but stricter and genetic studies find no real benefit, and alcohol raises cancer risk.
Sleep
- CIs melatonin safe to take every night?Melatonin caused only mild side effects in trials lasting up to a few months, and nightly use for years hasn't been tested well enough to call it proven safe.
- DHow much sleep do adults over 65 need?Most older adults seem to do best with about 7 to 8 hours a night. Studies linking sleep to health risks are observational, and few focus on people over 65.
Hormones
- AIs testosterone therapy safe for the heart?In middle-aged and older men with low testosterone, treatment did not raise the risk of heart attack, stroke or heart death over about 2 years. Atrial fibrillation (an irregular heartbeat) and blood clots in the lungs were more common.
- BIs hormone therapy safe after menopause?For healthy women under 60 or within 10 years of menopause, hormone therapy is reasonably safe for hot flashes. It raises the risk of blood clots, stroke and, with a progestin, breast cancer. Risks rise with age.
- BDoes DHEA do anything for older adults?Oral DHEA did little for healthy older adults in the larger, longer trials: no gain in strength, thinking or quality of life. A vaginal form eases menopause-related dryness and pain.
Brain
- CCan exercise slow cognitive decline?Exercise gave small gains in thinking and memory test scores in many trials, but it hasn't been shown to prevent dementia. Several trials found no edge over stretching.
- CDoes neurofeedback help anxiety?Neurofeedback eased anxiety in several small trials, but the best reviews can't separate its effect from placebo and attention. We don't know yet if it works better than other treatments.
- DDoes methylene blue improve memory?We don't know yet whether methylene blue improves everyday memory. Small, short trials hint at memory gains after a single low dose, and one found it could backfire.
- BDoes loneliness or social isolation predict early death?Yes. Socially isolated people died earlier in studies that followed people over time, about a third more often than connected people. Lonely people died about 15% more often, though results varied.
- DDoes hearing loss raise the risk of dementia, and do hearing aids help?Hearing loss is linked to a higher chance of dementia, roughly one and a third times as high. Whether hearing aids lower that risk is unproven, because the main trial found no benefit overall.
- BDoes a low Digit Symbol Substitution Test score predict dementia and death?Yes, in older adults a low score on this test is linked to a higher risk of death. It is also linked to dementia, though the dementia studies used related speed tests.
- CDoes Stroop color-word test performance predict cognitive decline or dementia?People with mild memory-related cognitive impairment do worse on Stroop-type tests than healthy people. No study has shown that one person's Stroop score predicts later decline or dementia.
- BDo slow breathing exercises reduce stress?Yes, slow breathing exercises lowered stress by a small to medium amount in trials of healthy and mixed adult groups. Most trials had some weaknesses, and the longer-term effect is less clear.
Tests
- AWhat does a coronary calcium score tell you?A coronary calcium score measures hardened plaque in the heart's arteries. A higher score is linked to more heart attacks and strokes, and a score of zero points to low risk.
- AIs ApoB a better test than LDL cholesterol?Yes, apoB predicts heart disease risk better than LDL cholesterol, mainly when the two disagree. Whether treating by apoB improves outcomes beyond treating by LDL isn't yet tested.
- DAre full-body MRI scans worth it?Probably not for healthy people with no symptoms. Scans found cancer in about 1 in 64 people, often turned up harmless findings, and no study shows people live longer or healthier.
- BWhat do epigenetic age tests actually measure?Epigenetic age tests read chemical tags on your DNA, mostly from blood, and turn them into an "age" estimate. That estimate predicts risk of death and disease, but whether it measures aging itself is unproven.
- ADoes the sitting-rising test predict how long you live?Yes. In middle-aged and older adults, people who needed hands or knees to sit and rise from the floor were much more likely to die over the next 6 to 12 years.
- CDoes being able to stand on one leg for 10 seconds predict survival?Yes, in middle-aged and older adults, people who couldn't hold the pose died about four times as often over 7 years. It's a warning sign for groups, and can't predict one person's future.
- BDoes walking speed predict how long older adults live?Yes. Older adults who walk slower are more likely to die sooner, and the link is consistent across many studies. It shows risk in groups and can't forecast one person's lifespan.
- CDoes the 30-second chair stand test predict falls in older adults?We don't know yet. Small studies give mixed results on whether the 30-second chair stand test predicts falls, and no single test predicts falls reliably.
- BDoes resting heart rate predict mortality?Yes. A faster resting heart rate is linked to a higher risk of early death, and the link holds in many large studies. Whether the heart rate itself causes the extra risk is unclear.
- BDoes waist-to-height ratio predict heart disease and death?Yes. In large studies following people over time, a higher waist-to-height ratio was linked to more heart disease and earlier death. It is a useful warning sign, not a forecast for any one person.
- CDoes push-up capacity predict heart disease?In one study of about 1,100 active male firefighters, men who could do more than 40 push-ups had far fewer heart events over 10 years. Larger studies are needed to confirm it.
- ADoes a higher Life's Essential 8 heart health score predict longer life?Yes. Adults with high Life's Essential 8 scores lived longer: roughly 40 to 45% lower risk of death than those with low scores, and about 9 more years of life expectancy at 50 in one study.
- ADoes cardiorespiratory fitness predict how long you live?Yes. People with high cardiorespiratory fitness die at about half the rate of people with low fitness over follow-up, and each step up in fitness is linked to lower risk.
- ADoes phenotypic age from routine blood tests predict mortality?Yes. People whose phenotypic age is older than their actual age die sooner, and in large studies it predicted death somewhat better than age alone.
- BHow accurate are the AHA PREVENT equations at predicting heart disease?The PREVENT equations rank people by heart disease risk well. They can still under- or over-estimate actual risk, and in some US health systems they predicted far fewer events than occurred.
- BHow accurate is the STOP-Bang questionnaire at detecting sleep apnea?STOP-Bang catches most people with sleep apnea in sleep clinics and before surgery, but it also flags many people who don't have it. A low score is more reliable than a high one.
- ADoes slower reaction time predict mortality?Yes. Slower reaction time is linked to a modestly higher risk of dying, about 10 to 14% higher in pooled results. It describes groups of people and can't predict one person's fate.
- CHow accurate is the ADA diabetes risk test at finding undiagnosed diabetes?The ADA risk test catches roughly 7 or 8 in 10 people with undiagnosed diabetes at best, and most who score high don't have it. Few studies tested the ADA score itself.
- CDoes the CDC Stay Independent questionnaire predict falls in older adults?Only a little. In one small study that tracked falls, the questionnaire sorted people who fell from those who didn't only slightly better than chance. We don't know yet how well it predicts falls.
- BDoes the FRAIL scale predict disability and death?Yes. Older adults scoring as frail on the FRAIL scale had several times the risk of later disability and death, though it sorts groups better than it predicts one person's fate.
- BHow accurate is the AUDIT-C at detecting unhealthy drinking?The AUDIT-C picks up most unhealthy drinking in primary care, but it misses some cases, especially in women. It works about as well as the full 10-question test.
- ADoes lower kidney function (eGFR) predict death and heart disease?Yes. Once eGFR falls below about 60, the risk of death and heart disease rises step by step, and it climbs steeply as kidney function drops further.
- CDoes postural sway predict falls in older adults?Sometimes, but not reliably. Some sway measures, especially side-to-side sway, are linked to later falls in some studies, and others found no link. Sway alone can't predict one person's falls.
- CHow accurate is the Amsler grid at detecting macular degeneration?The Amsler grid catches roughly 7 in 10 cases of wet macular degeneration, so it misses about 3 in 10. A normal grid result doesn't rule out disease.
Recovery
- CDo cold plunges help muscle recovery?Cold plunges eased muscle soreness a little after hard exercise in pooled trials. Strength and blood-marker results were mixed. Cold water may also blunt muscle gains from regular strength training.
- DDoes sauna use lower heart disease risk?Finnish men who used saunas often had fewer heart deaths over about 20 years. Whether the sauna itself lowers heart disease risk is unknown, because no trial has tested heart attacks or deaths.
- DDoes hyperbaric oxygen slow aging?We don't know yet. In two small trials of healthy older adults, 60 daily sessions improved thinking tests and fitness, but no study measured aging, frailty or lifespan.
Skin
- BDoes topical retinol reduce wrinkles?Yes, topical retinol modestly improves fine wrinkles, and the best evidence says it works about as well as other retinoid creams. Results show up over months, and the creams can irritate.
- CDo collagen supplements improve skin?Collagen supplements taken for about 12 weeks improved skin moisture and wrinkles a little in trials, mostly in women. Results on firmness were mixed, and many trials tested branded products.
- BDoes daily sunscreen slow skin aging?Yes, a little. In a four-and-a-half-year trial, adults who used sunscreen daily showed about a quarter less skin aging than those who used it as they chose.
- CDoes red light therapy improve skin aging?Yes, red light therapy modestly softened fine wrinkles around the eyes in small, short trials, with reductions near 30% in some. Lasting benefit and effects on deeper aging are unknown.
Aging research
- DDoes young plasma reverse aging?We don't know yet. Young plasma hasn't been shown to reverse aging in people. Small trials changed blood markers, and none measured how long or how well people live.
- UDo NAD+ IV infusions have benefits?We don't know yet. No outcome trials have tested NAD+ IV infusions for wellness or anti-aging, so benefits in people are unproven.