Educational only — this site does not provide personalised medical advice. Read the full disclaimer.
Source-cited

The reading list.

This site doesn’t run a blog — it reads papers and grades tests. Every study behind every grade is here, sorted by what it actually found. Nothing on this page is hand-written opinion: each entry is drawn from the same verified citation index as the methodology, so it grows when the evidence does.

The trials the grades rest on 106

Large randomised trials and cohorts that moved the needle — the papers a Strong or Moderate grade is borrowing its confidence from.

  • Adequate protein intake

    Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength. Br J Sports Med. 2018;52:376–384. PMID 28698222

    A 2018 systematic review and meta-regression (26 trials, over 800 participants) found that added protein improved strength and lean mass gains from resistance training, with the effect strongest in trained adults and tapering with age.

  • ApoB

    Sniderman AD, et al. JAMA Cardiol. 2019. PMID 31642874

    ApoB outperforms LDL-C for cardiovascular risk prediction, especially at discordant lipid values.

  • APOE genotyping

    Mayeux R, et al. N Engl J Med. 1998. PMID 9468467

    APOE genotype's predictive value for Alzheimer's risk is population-level, not reliable for individual prognosis.

  • Ashwagandha

    Chandrasekhar K et al., Indian J Psychol Med, 2012 (RCT, stress) PMID 23439798

    Three separate placebo-controlled trials anchor the grade.

  • Ashwagandha

    Lopresti AL et al., Medicine (Baltimore), 2019 (RCT, stress) PMID 31517876

    Three separate placebo-controlled trials anchor the grade.

  • Ashwagandha

    Langade D et al., J Ethnopharmacol, 2021 (RCT, sleep) PMID 32818573

    Three separate placebo-controlled trials anchor the grade.

  • Balance training

    Sherrington et al., Cochrane Database of Systematic Reviews 2019; exercise for preventing falls in older people living in the community (PMID 30703272) PMID 30703272

    A Cochrane review pooled 108 randomised trials covering 23,407 community-dwelling adults.

  • Balance training

    Montero-Odasso et al., Age and Ageing 2022; World guidelines for falls prevention and management for older adults (PMID 36178003) PMID 36178003

    A Cochrane review pooled 108 randomised trials covering 23,407 community-dwelling adults.

  • Berberine

    Dong H et al., Planta Med, 2013 (SR/MA, berberine and blood lipids) PMID 23512497

    Meta-analyses covering dozens of small trials find real drops in HbA1c (a three-month average of blood sugar control), LDL cholesterol and triglycerides, mostly in people with type 2 diabetes or metabolic syndrome.

  • Berberine

    Guo J et al., Oxid Med Cell Longev, 2021 (SR/MA, berberine in type 2 diabetes) PMID 34956436

    Meta-analyses covering dozens of small trials find real drops in HbA1c (a three-month average of blood sugar control), LDL cholesterol and triglycerides, mostly in people with type 2 diabetes or metabolic syndrome.

  • Berberine

    Liu D et al., Front Pharmacol, 2025 (SR/MA, berberine in metabolic syndrome) PMID 40740996

    Meta-analyses covering dozens of small trials find real drops in HbA1c (a three-month average of blood sugar control), LDL cholesterol and triglycerides, mostly in people with type 2 diabetes or metabolic syndrome.

  • CAC score

    Detrano R, et al. N Engl J Med. 2008 (MESA). PMID 18367736

    Coronary artery calcium score predicts coronary events across multiple ethnic groups, independent of traditional risk factors.

  • Caloric restriction

    Redman LM, et al. Metabolic Slowing and Reduced Oxidative Damage with Sustained Caloric Restriction. Cell Metab 2018. PMID 29576535

    CALERIE, a multicentre randomised controlled trial in 218 healthy adults of normal to slightly raised weight, asked volunteers to cut 25 percent of energy intake and achieved a sustained 12 percent, which brought meaningful weight loss…

  • Caloric restriction

    Kraus WE, et al. 2 years of calorie restriction and cardiometabolic risk (CALERIE): exploratory outcomes of a randomised controlled trial. Lancet Diabetes Endocrinol 2019. PMID 31303390

    CALERIE, a multicentre randomised controlled trial in 218 healthy adults of normal to slightly raised weight, asked volunteers to cut 25 percent of energy intake and achieved a sustained 12 percent, which brought meaningful weight loss…

  • CGM (non-diabetic)

    Cichosz SL, et al. Diabetes Technol Ther. 2025. PMID 39115921

    Glycemic variability indices from CGM separate healthy, prediabetic and type 2 diabetic groups — a real signal, not an outcome trial.

  • Coffee intake

    Gunter MJ, et al. Coffee Drinking and Mortality in 10 European Countries. Ann Intern Med 2017. PMID 28693038

    An umbrella review in the BMJ covering more than 200 meta-analyses found consumption of three to four cups a day carried the lowest observed risks for all-cause mortality and cardiovascular disease, with the clearest exception being…

  • Coffee intake

    Poole R, et al. Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ 2017. PMID 29167102

    An umbrella review in the BMJ covering more than 200 meta-analyses found consumption of three to four cups a day carried the lowest observed risks for all-cause mortality and cardiovascular disease, with the clearest exception being…

  • Coffee intake

    Loftfield E, et al. Association of Coffee Drinking With Mortality by Genetic Variation in Caffeine Metabolism: Findings From the UK Biobank. JAMA Intern Med 2018. PMID 29971434

    An umbrella review in the BMJ covering more than 200 meta-analyses found consumption of three to four cups a day carried the lowest observed risks for all-cause mortality and cardiovascular disease, with the clearest exception being…

  • Cold-water immersion

    Azevedo KP, et al. Different Cryotherapy Modalities Demonstrate Similar Effects on Muscle Performance, Soreness, and Damage in Healthy Individuals and Athletes: A Systematic Review and Meta-analysis. J Clin Med. 2022;11(15):4441. PMID 35956058

    A 2022 systematic review comparing cold-water immersion, ice massage and other cryotherapy modalities found similar small effects on soreness and perceived recovery across methods, with low-quality trials and short follow-up throughout.

  • Collagen peptides

    Shaw G, et al. Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. Am J Clin Nutr. 2017;105:136–143. PMID 27852613

    The trial most often cited by collagen sellers (Shaw et al.) showed raised circulating markers of collagen synthesis after vitamin-C-fortified gelatin taken before exercise.

  • Compression therapy (pneumatic boots)

    Canez MS et al., J Bodyw Mov Ther, 2025 (systematic review w/ MA, pneumatic compression for muscle recovery) PMID 40954632

    A 2025 systematic review with meta-analysis finds intermittent pneumatic compression gives small, inconsistent relief of post-exercise soreness versus resting, with little clear carry-over to next-day performance.

  • Compression therapy (pneumatic boots)

    Phung H et al., EClinicalMedicine, 2026 (network MA, compression systems for venous leg ulcers) PMID 42518940

    A 2025 systematic review with meta-analysis finds intermittent pneumatic compression gives small, inconsistent relief of post-exercise soreness versus resting, with little clear carry-over to next-day performance.

  • Creatine monohydrate

    Kreider RB, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18. PMID 28615996

    The International Society of Sports Nutrition's position stand reviews hundreds of trials: creatine monohydrate at about 3–5 g a day reliably increases muscle phosphocreatine, training output and lean mass, with an extensive safety record…

  • CRP / fibrinogen

    Kaptoge S, et al. N Engl J Med. 2012. PMID 23034020

    Adding CRP or fibrinogen to a conventional cardiovascular risk model produced only a slight improvement in prediction.

  • Curcumin

    Anand P et al., Mol Pharm, 2007 (curcumin bioavailability: problems and promises) PMID 17999464

    A landmark pharmacology review documents how poorly standard curcumin dissolves and gets absorbed, which is why enhanced formulations now fill the market.

  • Curcumin

    Bahari H et al., Inflammopharmacology, 2025 (SR/MA, curcumin and inflammatory markers) PMID 41240262

    A landmark pharmacology review documents how poorly standard curcumin dissolves and gets absorbed, which is why enhanced formulations now fill the market.

  • Cutting ultra-processed food

    Lane MM, et al. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ. 2024;384:e077310. PMID 38418082

    A 2024 BMJ umbrella review pooled the epidemiological meta-analyses: ultra-processed exposure was associated with higher risks of all-cause mortality, cardiovascular disease, type 2 diabetes, obesity and depression, with no outcome…

  • Cycling to work

    Oja et al., British Journal of Sports Medicine 2017; specific sports and mortality, cohort of 80,306 British adults (PMID 27895075) PMID 27895075

    In the UK Biobank, 263,450 middle-aged adults reported how they travelled to work and were followed for around five years.

  • Cycling to work

    Celis-Morales et al., BMJ 2017; active commuting and incident cardiovascular disease, cancer, and mortality, prospective cohort (PMID 28424154) PMID 28424154

    In the UK Biobank, 263,450 middle-aged adults reported how they travelled to work and were followed for around five years.

  • Cystatin C

    Shlipak MG, et al. N Engl J Med. 2013. PMID 24004120

    Cystatin C-based eGFR strengthened the link between kidney function and death, reclassifying many people labelled CKD by creatinine alone.

  • Daily multivitamin

    Gaziano JM, et al. Multivitamins in the prevention of cancer in men: the Physicians' Health Study II randomized controlled trial. JAMA. 2012;308:1871–1880. PMID 23162860

    The COSMOS-Mind trial reported multivitamin use slowed cognitive decline modestly over three years in older adults, a finding needing replication before it changes practice.

  • Daily multivitamin

    Baker LD, et al. Effects of cocoa extract and a multivitamin on cognitive function: A randomized clinical trial (COSMOS-Mind). Alzheimers Dement. 2023;19:1308–1319. PMID 36102337

    The COSMOS-Mind trial reported multivitamin use slowed cognitive decline modestly over three years in older adults, a finding needing replication before it changes practice.

  • Daily step count

    Paluch AE, et al. Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts. Lancet Public Health. 2022;7:e219–e228. PMID 35247352

    A 2022 meta-analysis pooling 15 international cohorts (about 47,000 adults) found progressively lower all-cause mortality with more steps, with the benefit levelling off between 6,000 and 8,000 steps a day for adults 60+ and between 8,000…

  • DASH diet

    Sacks FM, et al. Effects on blood pressure of reduced dietary sodium and the DASH diet. N Engl J Med 2001. PMID 11136953

    The original randomised trial in 459 adults found the fruit-and-vegetable-rich, low-fat dairy combination lowered systolic pressure by 5.5 mmHg overall and by 11.4 mmHg in those with hypertension, rivalling a starting blood-pressure tablet…

  • DASH diet

    Fung TT, et al. Adherence to a DASH-style diet and risk of coronary heart disease and stroke in women. Arch Intern Med 2008. PMID 18413553

    The original randomised trial in 459 adults found the fruit-and-vegetable-rich, low-fat dairy combination lowered systolic pressure by 5.5 mmHg overall and by 11.4 mmHg in those with hypertension, rivalling a starting blood-pressure tablet…

  • DASH diet

    Appel LJ, et al. A clinical trial of the effects of dietary patterns on blood pressure. N Engl J Med 1997. PMID 9099655

    The original randomised trial in 459 adults found the fruit-and-vegetable-rich, low-fat dairy combination lowered systolic pressure by 5.5 mmHg overall and by 11.4 mmHg in those with hypertension, rivalling a starting blood-pressure tablet…

  • DEXA (body composition)

    Kuk JL, et al. "Visceral fat is an independent predictor of all-cause mortality in men." PMID 16571861

    Visceral fat, measurable via DEXA, independently predicts all-cause mortality.

  • Drinking less alcohol

    Wood AM, et al. Risk thresholds for alcohol consumption: combined analysis of individual-participant data for 599 912 current drinkers in 83 prospective studies. Lancet. 2018;391:1513–1523. PMID 29676281

    A combined analysis of individual data from 83 prospective studies and close to 600,000 current drinkers found risk of stroke, coronary disease (outside light drinking), fatal hypertensive disease and several cancers rising monotonically…

  • EBV / nasopharyngeal

    Chan KCA, et al. N Engl J Med. 2017. PMID 28792880

    Plasma EBV DNA screening of 20,174 Hong Kong men detected nasopharyngeal carcinoma earlier, with better progression-free survival.

  • Exercise for brain health

    Blondell et al., BMC Public Health 2014; systematic review and meta-analysis of prospective studies on physical activity, cognitive decline and dementia (PMID 24885250) PMID 24885250

    A meta-analysis of 47 prospective cohorts compared highly active adults with low-activity peers.

  • Exercise for brain health

    Livingston et al., Lancet 2020; Dementia prevention, intervention, and care: 2020 report of the Lancet Commission (PMID 32738937) PMID 32738937

    A meta-analysis of 47 prospective cohorts compared highly active adults with low-activity peers.

  • Fibre intake

    Reynolds A, et al. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet 2019. PMID 30638909

    A 2019 series of systematic reviews in The Lancet pooled 185 prospective studies and dozens of controlled trials and found 15 to 30 percent lower rates of death from any cause, coronary heart disease, type 2 diabetes and colorectal cancer…

  • Fish intake

    Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health: evaluating the risks and the benefits. JAMA 2006. PMID 17047219

    A JAMA review weighing decades of evidence concluded that modest fish intake of one to two servings a week, particularly oily species, is associated with a 36 percent lower risk of coronary death and 17 percent lower total mortality, and…

  • Fish intake

    Jayedi A, et al. Fish consumption and risk of all-cause and cardiovascular mortality: a dose-response meta-analysis. Public Health Nutr 2018. PMID 29317009

    A JAMA review weighing decades of evidence concluded that modest fish intake of one to two servings a week, particularly oily species, is associated with a 36 percent lower risk of coronary death and 17 percent lower total mortality, and…

  • FIT / colorectal

    Davidson KW, et al. (USPSTF) JAMA. 2021. PMID 34003218

    USPSTF Grade A for colorectal cancer screening at 50–75 and Grade B at 45–49, with annual FIT an accepted strategy.

  • Food IgG panels

    Stapel SO, et al. Allergy. 2008. PMID 18489614

    EAACI task force: food-specific IgG4 reflects exposure and tolerance, not intolerance — the test is explicitly not recommended.

  • Grip strength

    Leong DP, et al. (PURE) Lancet. 2015. PMID 25982160

    In 139,691 adults across 17 countries, each 5 kg drop in grip strength predicted higher mortality — more strongly than systolic blood pressure.

  • Grounding (earthing)

    Chevalier G et al., J Environ Public Health, 2012 (earthing review) PMID 22291721

    The published base is thin.

  • Grounding (earthing)

    Oschman JL et al., J Inflamm Res, 2015 (review of grounding studies) PMID 25848315

    The published base is thin.

  • H. pylori

    Chiang TH, et al. Gut. 2021. PMID 32792335

    Population-wide H. pylori screen-and-treat reduced both gastric cancer incidence and mortality on the Matsu Islands.

  • Hepatitis B

    Krist AH, et al. (USPSTF) JAMA. 2020. PMID 33320230

    USPSTF Grade B: screen adolescents and adults at increased risk of hepatitis B, including people born where prevalence is ≥2%.

  • High-intensity interval training (HIIT)

    Milanović Z, et al. Effectiveness of High-Intensity Interval Training (HIT) and Continuous Endurance Training for VO2max Improvements: A Systematic Review and Meta-Analysis. Sports Med. 2015;45:1469–1481. PMID 26243014

    A meta-analysis of 27 trials comparing HIIT with continuous endurance training found VO2max improved more with intervals for the same amount of total work.

  • HIV

    Owens DK, et al. (USPSTF) JAMA. 2019. PMID 31184701

    USPSTF Grade A — the strongest classification issued — for HIV screening in everyone aged 15 to 65.

  • HOMA-IR

    Matthews DR, et al. Diabetologia. 1985. PMID 3899825

    Original derivation of the HOMA-IR model from fasting glucose and insulin.

  • hs-CRP

    Ridker PM, et al. N Engl J Med. 2008 (JUPITER). PMID 18997196

    Statin therapy reduced events in patients with elevated hs-CRP but normal LDL-C — the trial hs-CRP's "Moderate" grade rests on.

  • Hydrogen-rich water

    Song G et al., J Lipid Res, 2013 (RCT, hydrogen-rich water and lipids) PMID 23610159

    Bench science shows molecular hydrogen can neutralise certain harmful radicals, and a 2025 review maps dozens of small human trials across metabolic, liver and exercise settings.

  • Hydrogen-rich water

    Jin J et al., MedComm, 2025 (review: molecular hydrogen therapy) PMID 40297245

    Bench science shows molecular hydrogen can neutralise certain harmful radicals, and a 2025 review maps dozens of small human trials across metabolic, liver and exercise settings.

  • Hyperbaric oxygen therapy

    Fisher SM, et al. Hyperbaric Oxygen Therapy in Aesthetic Medicine and Anti-Aging: A Systematic Review. Aesthetic Plast Surg. 2025;49(9):2534–2544. PMID 39733047

    A 2025 systematic review of HBOT in aesthetic medicine and anti-aging concluded that while the therapy may prove useful, the evidence to support its use and justify its cost is limited, calling for large standardised randomised trials.

  • Ketogenic (very low-carb) diet

    Yancy WS, et al. Ann Intern Med. 2004;140:769–777. PMID 15148063

    A low-carbohydrate ketogenic diet produced greater weight loss at 6 months than a low-fat diet in adults with obesity; the difference narrowed by 12 months.

  • Ketogenic (very low-carb) diet

    Parry-Strong A, et al. Diabetes Obes Metab. 2022;24:2431–2442. PMID 36064937

    Meta-analysis of randomised trials: very-low-carbohydrate (ketogenic) diets improved HbA1c and triglycerides in type 2 diabetes at 6–12 months, with greater early weight loss.

  • Ketogenic (very low-carb) diet

    Seidelmann SB, et al. Lancet Public Health. 2018;3:e419–e428. PMID 30122560

    U-shaped association: both very low and very high carbohydrate intake were linked to higher all-cause mortality; lowest-carbohydrate diets with animal-based fat/protein carried the highest risk.

  • Lp(a)

    Kamstrup PR, et al. JAMA. 2009. PMID 19509380

    Elevated Lp(a) independently predicts myocardial infarction risk in the general population.

  • Lp-PLA2

    Thompson A, et al. Lancet. 2010. PMID 20435228

    Lp-PLA2 was associated with coronary risk at a magnitude comparable to conventional risk factors, across 32 prospective studies.

  • Magnesium supplements

    Argeros Z, et al. Magnesium Supplementation and Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Hypertension. 2025;82(11):1844–1856. PMID 41000008

    A 2025 meta-analysis of randomised controlled trials in Hypertension mapped magnesium supplementation to small systolic and diastolic blood-pressure reductions, examined across doses and durations.

  • Mammography

    Nicholson WK, et al. (USPSTF) JAMA. 2024. PMID 38687503

    USPSTF Grade B for biennial screening mammography at 40–74, lowering the start age from 50.

  • Massage therapy

    Rizzo RR et al., Cochrane Database Syst Rev, 2025 (overview: non-drug treatments for low back pain) PMID 40139265

    A 2025 overview of Cochrane reviews counts massage among the hands-on options with small short-term gains in low back pain, with benefits shrinking over following months.

  • Mediterranean diet

    Estruch R, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013;368:1279–1290. PMID 23432189

    The PREDIMED trial randomised about 7,400 people at high cardiovascular risk to a Mediterranean diet plus extra-virgin olive oil, the same diet plus nuts, or general low-fat advice.

  • Multi-cancer detection

    Klein EA, et al. Ann Oncol. 2021. PMID 34176681

    Multi-cancer early detection showed high specificity but sensitivity that falls sharply in early-stage disease.

  • Multi-cancer detection

    Neal RD, et al. Cancers. 2022. PMID 36230741

    Design paper for NHS-Galleri, the randomised trial built to test whether multi-cancer early detection reduces mortality.

  • Multi-cancer early detection

    Lennon AM, Buchanan AH, Rego SP Cancer Prev Res (Phila). 2024. PMID 38705577

    DETECT-A, the first large prospective interventional study of a multi-cancer early detection blood test, reports the outcomes after a positive result in asymptomatic people - the first real data on the follow-up cascade such a test sets off.

  • N-acetylcysteine (NAC)

    Zheng JP et al., Lancet Respir Med, 2014 (PANTHEON randomised trial, COPD) PMID 24621680

    The strongest human evidence lives in lung medicine.

  • N-acetylcysteine (NAC)

    Huang C et al., Ther Adv Respir Dis, 2023 (meta-analysis, NAC in COPD) PMID 36927162

    The strongest human evidence lives in lung medicine.

  • NMN / NR (NAD+ boosters)

    Chen F, et al. Effects of Nicotinamide Mononucleotide on Glucose and Lipid Metabolism in Adults: A Systematic Review and Meta-analysis of Randomised Controlled Trials. Curr Diab Rep. 2025;25(1):4. PMID 39531138

    A 2024 systematic review of randomised trials found NMN produced modest improvements in insulin sensitivity and lipid measures in some small studies, with heterogeneous designs, short durations and no hard endpoints anywhere.

  • Nut consumption

    Bao Y, et al. Association of nut consumption with total and cause-specific mortality. N Engl J Med 2013. PMID 24256379

    Thirty years of follow-up in about 119,000 US health professionals found those eating nuts seven or more times a week had 20 percent lower all-cause mortality than those who never ate them, and nut eaters were actually leaner despite the…

  • Nut consumption

    Estruch R, et al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. N Engl J Med 2018. PMID 29897866

    Thirty years of follow-up in about 119,000 US health professionals found those eating nuts seven or more times a week had 20 percent lower all-cause mortality than those who never ate them, and nut eaters were actually leaner despite the…

  • Omega-3 index

    Harris WS, von Schacky C. Prev Med. 2004. PMID 15208005

    Proposes the omega-3 index itself as a candidate cardiovascular risk marker.

  • Overdiagnosis

    Jung M Curr Probl Cancer. 2017. PMID 28104314

    Review of overdiagnosis across breast, prostate and thyroid cancer screening: some abnormalities detected by screening would never have caused harm, which is harm caused by screening itself.

  • Overdiagnosis

    Marcondes FO, Armstrong K Ann Intern Med. 2022. PMID 35226534

    Reducing the burden of overdiagnosis in breast cancer screening and beyond: the scale of overdiagnosis and the paths to reducing it.

  • Plant-based diet

    Yokoyama Y, et al. Vegetarian diets and blood pressure: a meta-analysis. JAMA Intern Med 2014. PMID 24566947

    A meta-analysis of 39 observational studies and clinical trials found vegetarian patterns associated with systolic pressure about 5 mmHg lower than omnivorous comparison groups (Yokoyama et al., JAMA Intern Med 2014).

  • Plant-based diet

    Dinu M, et al. Vegetarian, vegan diets and multiple health outcomes: a systematic review with meta-analysis of observational studies. Crit Rev Food Sci Nutr 2017. PMID 26853923

    A meta-analysis of 39 observational studies and clinical trials found vegetarian patterns associated with systolic pressure about 5 mmHg lower than omnivorous comparison groups (Yokoyama et al., JAMA Intern Med 2014).

  • Plant-based diet

    Melina V, Craig W, Levin S. Position of the Academy of Nutrition and Dietetics: Vegetarian Diets. J Acad Nutr Diet 2016. PMID 27886704

    A meta-analysis of 39 observational studies and clinical trials found vegetarian patterns associated with systolic pressure about 5 mmHg lower than omnivorous comparison groups (Yokoyama et al., JAMA Intern Med 2014).

  • PSA

    Schröder FH, et al. (ERSPC) Lancet. 2014. PMID 25108889

    ERSPC at 13 years: PSA screening cut prostate cancer mortality, but ~27 extra men had to be diagnosed to prevent one death.

  • Red-light therapy

    Wunsch A, Matuschka K. A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles and skin roughness over time. Photomed Laser Surg. 2014;32:93–100. PMID 24286286

    A controlled trial of red and near-infrared light found measurable improvement in skin roughness and wrinkle ratings versus sham over 30 sessions, supporting the narrow cosmetic claim.

  • Resistance training

    Momma H, et al. Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases: a systematic review and meta-analysis of cohort studies. Br J Sports Med. 2022;56:755–763. PMID 35228201

    A 2022 systematic review of prospective cohorts found 30–60 minutes a week of muscle-strengthening activity was associated with a 10–20% lower risk of all-cause mortality, cardiovascular disease, cancer and diabetes, with the curve…

  • Resveratrol

    Berman AY, et al. The therapeutic potential of resveratrol: a review of clinical trials. NPJ Precis Oncol. 2017;1:35. PMID 28989978

    A review of completed resveratrol clinical trials found effects concentrated in small studies of inflammatory markers and endothelial function, inconsistent across doses and populations, with no trial showing reduced cardiovascular events,…

  • Sauna bathing

    Laukkanen T, et al. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Intern Med. 2015;175:542–548. PMID 25705824

    The main evidence comes from the Kuopio Ischaemic Heart Disease cohort of middle-aged Finnish men, where men taking 4–7 sessions a week had substantially lower cardiovascular and all-cause mortality over two decades of follow-up than…

  • Screening ethics

    Yong SEF, Wong ML, Voo TC BMC Med Ethics. 2022. PMID 35672820

    Peer-reviewed Singapore analysis arguing that health screening packages are not always beneficial for people without symptoms - the closest published statement of this site's thesis, from Singapore.

  • Sleep consistency

    Windred DP, et al. Sleep regularity is a stronger Predictor of mortality risk than sleep duration: A prospective cohort study. Sleep. 2024;47(1):zsad253. PMID 37738616

    In a prospective UK Biobank analysis of about 88,000 adults wearing accelerometers, sleep regularity predicted mortality more strongly than duration did, with the most irregular quintile at substantially raised risk across cardiovascular…

  • Sleeping 7–9 hours

    Cappuccio FP, et al. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep. 2010;33:585–592. PMID 20469800

    A systematic review and meta-analysis of prospective cohorts (over 1.3 million participants) found short sleep, under about seven hours, carried a 12% higher all-cause mortality risk, with the pooled curve bottoming out at seven hours or a…

  • Sodium (salt) reduction

    Aburto NJ, et al. Effect of lower sodium intake on health: systematic review and meta-analyses. BMJ 2013. PMID 23558163

    The hardest evidence is a randomised trial of about 21,000 older adults in rural China in which replacing ordinary salt with a potassium-enriched substitute cut strokes by 14 percent and premature deaths by 12 percent (Neal et al., NEJM…

  • Sodium (salt) reduction

    Neal B, et al. Effect of Salt Substitution on Cardiovascular Events and Death. N Engl J Med 2021. PMID 34459569

    The hardest evidence is a randomised trial of about 21,000 older adults in rural China in which replacing ordinary salt with a potassium-enriched substitute cut strokes by 14 percent and premature deaths by 12 percent (Neal et al., NEJM…

  • Taurine

    Singh P et al., Science, 2023 (taurine deficiency as a driver of aging) PMID 37289866

    The 2023 Science paper tracked taurine decline across species, then found supplementation lengthened life in middle-aged mice and improved monkey health markers.

  • Taurine

    Nie Z et al., Nutr Rev, 2025 (meta-analysis of oral taurine RCTs) PMID 41275513

    The 2023 Science paper tracked taurine decline across species, then found supplementation lengthened life in middle-aged mice and improved monkey health markers.

  • Testosterone

    Lincoff AM, et al. N Engl J Med. 2023 (TRAVERSE). PMID 37326322

    Cardiovascular safety of testosterone replacement in men with hypogonadism and pre-existing CV risk — the largest RCT of its kind.

  • Thyroid ultrasound

    Ahn HS, et al. N Engl J Med. 2014. PMID 25372084

    Korea's thyroid cancer diagnoses rose fifteen-fold after ultrasound screening spread, with no change in thyroid cancer mortality.

  • uACR

    Matsushita K, et al. Lancet. 2010. PMID 20483451

    Albuminuria predicted all-cause and cardiovascular mortality independently of eGFR across 21 cohorts and >1.2 million people.

  • Vibration plate training (whole-body vibration)

    de Oliveira RDJ et al., Osteoporos Int, 2023 (SR/MA, WBV and bone density in postmenopausal women) PMID 36282343

    A 2023 meta-analysis of randomised trials in postmenopausal women found small improvements in bone density under whole-body vibration.

  • Vibration plate training (whole-body vibration)

    Tan X et al., Arch Phys Med Rehabil, 2023 (SR/MA, WBV strength and performance in older adults) PMID 37169245

    A 2023 meta-analysis of randomised trials in postmenopausal women found small improvements in bone density under whole-body vibration.

  • Vitamin D

    USPSTF Recommendation Statement. JAMA. 2021. PMID 33847711

    Evidence insufficient to assess benefit/harm of screening asymptomatic adults for vitamin D deficiency (Grade I).

  • VO2 max

    Mandsager K, et al. JAMA Netw Open. 2018. PMID 30646252

    Across 122,007 patients, cardiorespiratory fitness was inversely associated with mortality with no observed ceiling of benefit.

  • Walking after meals

    DiPietro et al., Diabetes Care 2013; three 15-min postmeal walks improved 24-h glycemic control (PMID 23761134) PMID 23761134

    The cleanest trial here is small.

  • Walking after meals

    Buffey et al., Sports Medicine 2022; meta-analysis, light-intensity walking breaks attenuate postprandial glucose and insulin (PMID 35147898) PMID 35147898

    The cleanest trial here is small.

  • Whole-body electrical stimulation (EMS)

    Teschler M, et al. Four weeks of electromyostimulation improves muscle function and strength in sarcopenic patients: a three-arm parallel randomized trial. J Cachexia Sarcopenia Muscle. 2021;12(4):843–854. PMID 34105256

    A three-arm randomised trial found four weeks of electromyostimulation improved muscle function and strength in sarcopenic patients, supporting its use where conventional training is hard to access.

  • Yoga

    Cramer et al., American Journal of Hypertension 2014; systematic review and meta-analysis of yoga for hypertension (PMID 24795403) PMID 24795403

    Start with blood pressure, the best-studied endpoint here.

  • Yoga

    Geiger et al., PLOS ONE 2025; updated systematic review and meta-analysis of yoga for arterial hypertension (PMID 40367243) PMID 40367243

    Start with blood pressure, the best-studied endpoint here.

  • Zone 2 cardio

    Bull FC, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med. 2020;54:1451–1462. PMID 33239350

    The WHO 2020 guidelines on physical activity grade the link between regular moderate-intensity aerobic activity and lower all-cause mortality, cardiovascular disease, type 2 diabetes and depression at the highest confidence level, drawing…

Where the evidence says no 17

Trials that tested the marketing claim and came back empty. These are why several expensive tests grade Weak.

  • Bundled/package panels

    Krogsbøll LT, et al. Cochrane Database Syst Rev. 2019. PMID 30699470

    15 RCTs, 250,000+ participants: general health checks in adults do not reduce all-cause, cardiovascular, or cancer mortality.

  • Carotid ultrasound

    USPSTF Recommendation Statement. JAMA. 2021. PMID 34058106

    Recommends against screening asymptomatic adults for carotid artery stenosis.

  • Chest X-ray

    Oken MM, et al. (PLCO) JAMA. 2011. PMID 22031728

    154,901 adults randomised to annual chest radiograph or usual care: no reduction in lung cancer mortality at 13 years.

  • Ferritin / haemochromatosis

    USPSTF Recommendation Statement. Ann Intern Med. 2006. PMID 16880462

    Recommends against routine genetic screening for hereditary haemochromatosis in asymptomatic adults (Grade D). Note: USPSTF marked this topic "inactive" in 2018 — not superseded by a contradicting statement, simply not re-reviewed since.

  • Homocysteine

    Lonn E, et al. N Engl J Med. 2006. PMID 16531613

    B-vitamin therapy lowered homocysteine but did not reduce cardiovascular events — the classic "confounded biomarker" case.

  • Omega-3 supplements (fish oil)

    Manson JE, et al. Marine n-3 Fatty Acids and Prevention of Cardiovascular Disease and Cancer. N Engl J Med. 2019;380:23–32. PMID 30415637

    VITAL randomised 25,871 adults to 1 g a day of marine omega-3 or placebo and found no significant reduction in major cardiovascular events or cancer.

  • Omega-3 supplements (fish oil)

    Nicholls SJ, et al. Effect of High-Dose Omega-3 Fatty Acids vs Corn Oil on Major Adverse Cardiovascular Events: The STRENGTH Randomized Clinical Trial. JAMA. 2020;324:2268–2280. PMID 33190147

    VITAL randomised 25,871 adults to 1 g a day of marine omega-3 or placebo and found no significant reduction in major cardiovascular events or cancer.

  • PSA

    Grossman DC, et al. (USPSTF) JAMA. 2018. PMID 29801017

    USPSTF Grade C for PSA screening at 55–69 (individual decision) and Grade D at 70 and over.

  • Resting ECG

    Curry SJ, et al. (USPSTF) JAMA. 2018. PMID 29896632

    USPSTF Grade D against resting/exercise ECG screening in low-risk asymptomatic adults; Grade I at intermediate or high risk.

  • Stretching & mobility work

    Herbert RD, et al. Stretching to prevent or reduce muscle soreness after exercise. Cochrane Database Syst Rev. 2011;(7):CD004577. PMID 21735398

    The Cochrane review of stretching trials found stretching before or after exercise produces small or no reductions in muscle soreness, with similar unimpressive results for injury prevention.

  • Thyroid (TSH)

    US Preventive Services Task Force. Ann Intern Med. 2004. PMID 14734336

    Insufficient evidence to recommend routine thyroid screening in asymptomatic, non-pregnant adults.

  • Thyroid ultrasound

    Bibbins-Domingo K, et al. (USPSTF) JAMA. 2017. PMID 28492905

    USPSTF Grade D against screening for thyroid cancer in asymptomatic adults.

  • Time-restricted eating

    Liu D, et al. Calorie Restriction with or without Time-Restricted Eating in Weight Loss. N Engl J Med. 2022;386:1495–1504. PMID 35443107

    A one-year randomised trial in 139 adults with obesity compared time-restricted eating with everyday calorie counting and found no significant difference in weight loss, waist circumference or metabolic markers.

  • Tonometry / glaucoma

    Mangione CM, et al. (USPSTF) JAMA. 2022. PMID 35608574

    USPSTF Grade I: insufficient evidence to assess screening asymptomatic adults for primary open-angle glaucoma.

  • Tumour markers (CA 125)

    Menon U, et al. (UKCTOCS) Lancet. 2021. PMID 33991479

    UKCTOCS randomised 202,638 women to CA 125-based screening: more early-stage disease found, no significant mortality reduction.

  • Vitamin D

    Manson JE, et al. N Engl J Med. 2019 (VITAL). PMID 30415629

    25,871 adults randomised to vitamin D3 2000IU/day vs. placebo: no significant reduction in cancer incidence or major CV events over 5 years.

  • Vitamin D

    USPSTF Recommendation Statement. Ann Intern Med. 2014. PMID 25419853

    Same "insufficient evidence" verdict as the 2021 update, reached independently 7 years earlier.

Worth watching, not yet worth buying 2

Genuinely interesting signals with the outcome trial still missing — the Emerging grade, honestly labelled.

  • Epigenetic clocks

    "From population science to the clinic? Limits of epigenetic clocks as personal biomarkers." Epigenomics. 2025. PMID 41403206

    Technical and biological limitations mean epigenetic clocks are not yet fit for individual-level clinical decisions, even though they work at a population level.

  • Gut microbiome testing

    Porcari S, et al. (international consensus statement). Lancet Gastroenterol Hepatol. 2024. PMID 39647502

    Expert panel concludes evidence for clinical utility of commercial microbiome testing remains scarce; calls for standardised reporting.