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1. Mindpreliminary · human dataAdded 30 August 2026

   Depression and smoking raise back pain risk, and back pain returns the favour

   A bidirectional Mendelian randomisation study using genetic data found evidence that greater education (odds ratio 0.54 per 4.2 years of schooling), ever smoking (1.27), greater alcohol consumption (1.29 per category increase) and major depressive disorder (1.41) causally increase the risk of chronic back pain. In the reverse direction, chronic back pain increased alcohol consumption (1.19) and smoking (1.21), while physical activity and sleep did not meet the study's criteria for a causal link.

   ⚠What it shows: Stronger than a simple correlation, weaker than a trial: this method uses inherited genetic differences as stand-ins for lifestyle exposures, which sidesteps some confounding but rests on assumptions that can fail. The genetic data came from people of European ancestry, so it may not carry over to other populations.Meta-analysis · Eur Spine J

   Full breakdown →Back Pain →Causal effects of psychosocial factors on chronic back pain: a bidirectional Mendelian randomisation study. Eur Spine J 2022
2. Metabolic & GLP-1well supported · human dataAdded 29 August 2026

   Weight-loss jabs shed muscle too: semaglutide users lost 5.44 kg of lean mass

   Pooled results from seven trials in 821 people with obesity show GLP-1 drugs at weight-loss doses reduced absolute lean mass by an average of 1.74 kg, with semaglutide showing the biggest loss at 5.44 kg. Even so, lean mass as a proportion of total body weight improved by 1.81%, since total weight fell faster still.

   ⚠What it shows: Reasonably solid on the headline numbers: results pooled from seven trials covering 821 people with obesity, all tested against placebo. The trials disagreed a lot on the size of the muscle loss, and none compared the drugs against diet and exercise plans, so it cannot say how much muscle a person who trains would keep.Meta-analysis · Int J Obes (Lond)

   Full breakdown →Sarcopenia explained →Protein Intake Calculator →Effect of GLP-1 receptor agonists at doses for obesity management on muscle health: systematic review and meta-analysis of randomized controlled trials (RCTs). Int J Obes (Lond) 2026
3. Bones & Jointspreliminary · human dataAdded 29 August 2026

   Knee arthritis pain fell sharply with machine-based strength training

   Pooled results from nine trials in 696 people with knee osteoarthritis found isokinetic strength training, done on machines that control movement speed, produced a large improvement in pain and a moderate one in disability, and it was well tolerated.

   ⚠What it shows: Encouraging but not settled: results pooled from nine trials covering 696 people with knee osteoarthritis, all judged low to moderate quality. The programmes and outcome measures varied so much that the authors say firm guidance on how to deliver this training is not yet possible.Meta-analysis · Ann Phys Rehabil Med

   Full breakdown →Isokinetic muscle strengthening for knee osteoarthritis: A systematic review of randomized controlled trials with meta-analysis. Ann Phys Rehabil Med 2016
4. Immunitypreliminary · human dataAdded 29 August 2026

   The lower the vitamin D, the higher the COVID death rate

   Across one population study and seven clinical studies, lower blood vitamin D3 levels correlated with higher COVID-19 mortality, and a regression through the pooled data pointed to a theoretical zero-mortality level near 50 ng/mL. That is a correlation and an extrapolation, not proof that raising vitamin D prevents deaths.

   ⚠What it shows: Treat this as a pattern, not proof: it pools one population study and seven hospital studies where lower vitamin D went with more deaths, and following people like this cannot show that raising vitamin D would have saved anyone. The zero-deaths level at 50 ng/mL is a line extended beyond the data, never tested in a trial.Meta-analysis · Nutrients

   Full breakdown →Vitamin D explained →COVID-19 Mortality Risk Correlates Inversely with Vitamin D3 Status, and a Mortality Rate Close to Zero Could Theoretically Be Achieved at 50 ng/mL 25(OH)D3: Results of a Systematic Review and Meta-Analysis. Nutrients 2021
5. Nutritionwell supported · human dataAdded 29 August 2026

   Cutting calories lowered blood pressure about as much as medication

   Pooled results from 32 randomised trials in 1722 adults show calorie restriction lasting one to four weeks lowered systolic blood pressure by 5.5 mmHg, an effect the authors say is similar to what medication achieves. Restriction lasting up to six months also slowed resting heart rate and improved VO2peak.

   ⚠What it shows: Strong for the short term: pooled from 32 trials in 1722 adults, the blood pressure drop looks real, but most interventions lasted weeks to months, so nobody knows whether the benefit survives once normal eating resumes. The literature search also stopped in June 2017, so newer trials are missing.Meta-analysis · Clin Nutr

   Full breakdown →Energy balance explained →Calorie Deficit Calculator →The effect of caloric restriction on blood pressure and cardiovascular function: A systematic review and meta-analysis of randomized controlled trials. Clin Nutr 2021
6. Mindwell supported · human dataAdded 29 August 2026

   Exercise and meditation eased student depression about equally

   Across 44 trials, aerobic exercise, traditional Chinese exercises and meditation each produced moderate reductions in college students' depressive symptoms, with broadly similar effects across the three approaches.

   ⚠What it shows: Reasonably solid on the broad conclusion: results pooled from 44 trials all pointed the same way, but the individual studies disagreed with each other a lot, so the true size of the benefit is uncertain. Every participant was a college student, so older adults may respond differently.Meta-analysis · Medicine (Baltimore)

   Full breakdown →Effects of aerobic exercise, traditional Chinese exercises, and meditation on depressive symptoms of college student: A meta-analysis of randomized controlled trials. Medicine (Baltimore) 2021
7. Trainingwell supported · human dataAdded 29 August 2026

   Mind-body exercise matched weights for fibromyalgia pain relief

   Pooled data from 21 trials in 1638 people with fibromyalgia, mostly women, found mind-body exercise and resistance training gave the largest reductions in pain, while mind-body exercise also improved six-minute walking distance.

   ⚠What it shows: Useful but loosely stitched: results pooled from 21 trials in 1638 people, mostly women, and the different exercise types were often compared indirectly rather than head to head. Take the rankings as a guide rather than a verdict.Meta-analysis · Pain Res Manag

   Full breakdown →Mind-body therapies explained →Comparison of the Effects of Three Types of Exercise (Aerobic Exercise, Resistance Training, and Mind-Body Exercise) on Fibromyalgia: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials. Pain Res Manag 2026
8. Tech & Wearableswell supported · human dataAdded 29 August 2026

   Phone-based weight loss programmes work, just not by much

   Weight-loss programmes delivered through mobile phones helped overweight and obese adults lose an average of 1.44 kg more than control groups, according to pooled results from 14 randomised trials involving 1,337 participants.

   ⚠What it shows: Solid but modest: results pooled from 14 trials in 1,337 overweight or obese adults all pointed the same way, yet the average extra loss was under two kilos. The search stopped in 2014, so today's apps and wearables were never part of the evidence.Meta-analysis · Am J Epidemiol

   Full breakdown →Energy balance explained →Calorie Deficit Calculator →Mobile phone intervention and weight loss among overweight and obese adults: a meta-analysis of randomized controlled trials. Am J Epidemiol 2015
9. Cardiowell supported · human dataAdded 29 August 2026

   HIIT improves 14 health markers at once, from blood pressure to body fat

   High-intensity interval training improved 14 cardiometabolic health markers in a meta-analysis of 97 randomised trials with 3,399 participants, including peak aerobic capacity, systolic and diastolic blood pressure, resting heart rate, waist circumference, body fat and blood fats.

   ⚠What it shows: About as broad as exercise evidence gets: results pooled from 97 trials in 3,399 people from the general population, all pointing the same way. Each individual improvement was modest, and HIIT was compared against doing nothing rather than against other forms of exercise.Meta-analysis · Sports Med

   Full breakdown →HIIT explained →Heart Rate Zone Calculator →High-Intensity Interval Training and Cardiometabolic Health in the General Population: A Systematic Review and Meta-Analysis of Randomised Controlled Trials. Sports Med 2023
10. Sleepwell supported · human dataAdded 29 August 2026

    Cut sleep and insulin sensitivity drops; fragment it and nothing happens

    Restricting sleep reduced insulin sensitivity in a meta-analysis of randomised trials, and both shifting sleep timing against the body clock and suppressing deep sleep also impaired it, while fragmented sleep and disturbed REM sleep had no measurable effect.

    ⚠What it shows: Strong for a short-term effect: results pooled from 21 trials where sleep was deliberately cut show insulin sensitivity dropping on several different measures. These were brief laboratory-style manipulations, so they cannot say how years of habitually short sleep play out.Meta-analysis · Sleep Med Rev

    Full breakdown →Insulin sensitivity explained →Sleep Calculator →Effects of sleep manipulation on markers of insulin sensitivity: A systematic review and meta-analysis of randomized controlled trials. Sleep Med Rev 2022
11. Recoverypreliminary · human dataAdded 29 August 2026

    Tart cherry eases the ache but does not speed the repair

    A network meta-analysis of 30 trials in 595 healthy adults found that tart cherry and pomegranate reduced muscle soreness at 48 hours after damaging exercise, but no polyphenol supplement showed clear benefits for muscle strength or blood markers of damage and inflammation.

    ⚠What it shows: Worth a measured read: the soreness relief looks plausible but the authors rate the overall evidence as low certainty, pooled from 30 trials totalling 595 healthy adults. Objective recovery measures did not improve for any supplement tested.Systematic review · Front Nutr

    Full breakdown →DOMS explained →Recovery Readiness Index →Comparative effects of plant-derived anthocyanin- and flavanol-rich supplements on recovery outcomes after exercise-induced muscle damage: a systematic review and network meta-analysis. Front Nutr 2026
12. Mindpreliminary · human dataAdded 29 August 2026

    Exercise may slow mental decline in diabetes, and variety wins

    Pooling 12 randomised trials with 1193 participants, exercise programmes were linked to better cognitive function in people living with diabetes, with the strongest results from multi-component exercise done more than 4 times a week, in sessions over 40 minutes, sustained for more than 6 months.

    ⚠What it shows: Promising direction, uncertain size: the pooled benefit comes from 12 trials in 1193 people, and the trials disagreed with each other a great deal. The optimal dose findings come from comparing across studies rather than trials designed to test one dose against another.Meta-analysis · PLoS One

    Full breakdown →Executive function explained →The effect of multi-component exercise on cognition function in patients with diabetes: A systematic review and meta-analysis. PLoS One 2024
13. Women's Healthpreliminary · human dataAdded 29 August 2026

    Exercise lowers blood pressure after menopause, and more is not always better

    In a dose-response network meta-analysis of 74 trials with 3,573 mostly postmenopausal women, exercise was associated with non-linear blood pressure reductions, with the largest predicted drops of 6.70 mmHg systolic near 1,400 METs-min per week and 4.20 mmHg diastolic near 1,500 METs-min per week.

    ⚠What it shows: Treat the sweet spot as a rough guide, not a target: it comes from pooling 74 trials in 3,573 women, and the authors rate the evidence as very low to low certainty. The apparent levelling off at higher doses also depended on which statistical model was chosen.Systematic review · Front Med (Lausanne)

    Full breakdown →Blood pressure explained →Heart Age Calculator →Exercise dose and modality for blood pressure reduction in predominantly postmenopausal women: a dose-response network meta-analysis. Front Med (Lausanne) 2026
14. Supplementswell supported · human dataAdded 29 August 2026

    Creatine plus lifting builds more ageing muscle than lifting alone

    Meta-analyses indicate that combining creatine supplementation with resistance training improves ageing muscle mass and upper body strength beyond resistance training alone, and creatine also shows promise for bone mineral density and indices of bone biology.

    ⚠What it shows: Reasonably solid for muscle and upper body strength: the conclusion rests on pooled trials of creatine combined with resistance training in the context of ageing. The bone findings are promising rather than proven, and the abstract does not report how large the added benefits are.Meta-analysis · Endocrine

    Full breakdown →Creatine monohydrate guide →Creatine Calculator →Creatine supplementation and aging musculoskeletal health. Endocrine 2014
15. Longevitywell supported · human dataAdded 29 August 2026

    Coffee's sweet spot: 4 cups a day linked to 16% lower death risk

    A dose-response meta-analysis of 21 prospective studies covering 997,464 people and 121,915 deaths found coffee drinking was associated with lower mortality, with the largest reductions at 4 cups a day for all-cause death (16%) and 3 cups a day for cardiovascular death (21%). Coffee showed no association with cancer mortality.

    ⚠What it shows: A strong pattern but still an association: these studies followed coffee drinkers over time rather than assigning coffee at random, so coffee is not proven to extend life. The pooled data cover 997,464 people across 21 studies, which makes the pattern hard to dismiss but easy to over-read.Meta-analysis · Am J Epidemiol

    Full breakdown →All-cause mortality explained →Caffeine Half-Life Calculator →Coffee consumption and mortality from all causes, cardiovascular disease, and cancer: a dose-response meta-analysis. Am J Epidemiol 2014
16. Nutritionwell supported · human dataAdded 29 August 2026

    The pigment that makes berries purple may tune blood sugar and cholesterol

    A meta-analysis of 32 randomised trials with 1491 participants found anthocyanin supplementation significantly reduced fasting glucose, post-meal glucose, glycated haemoglobin, total cholesterol and LDL cholesterol in both healthy people and those with cardiometabolic disease.

    ⚠What it shows: Fairly convincing on direction, less so on size: results pooled from 32 trials in 1491 people held up even after removing the weaker studies, but the trials disagreed with each other considerably and the best dose and formulation remain unknown.Meta-analysis · Adv Nutr

    Full breakdown →Insulin sensitivity explained →Metabolic Fitness Index →Effects of Anthocyanins on Cardiometabolic Health: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Adv Nutr 2017
17. Tech & Wearableswell supported · human dataAdded 28 August 2026

    The best health apps pair exercise with self-management coaching

    Across 137 randomised trials in 18,443 people with chronic conditions, digital programmes combining exercise with self-management support increased physical activity more than usual care, and delivery via mixed technologies such as apps with phone calls or devices worked best.

    ⚠What it shows: Fairly trustworthy: results pooled from 137 trials in 18,443 people, with moderate confidence in most comparisons. Gains were biggest in type 2 diabetes and smallest in muscle and joint conditions, so the payoff depends on what you are managing.Meta-analysis · J Phys Act Health

    Full breakdown →Effect of Components and Delivery Modes of Digital Health Interventions Targeting Physical Activity in People With a Chronic Condition or Multimorbidity: A Systematic Review and Component Network Meta-Analysis of Randomized Controlled Trials. J Phys Act Health 2025
18. Mindpreliminary · human dataAdded 28 August 2026

    Pairing workouts with brain training gives older minds a small extra edge

    Adding cognitive training to an exercise programme gave older adults a small extra improvement in cognitive function compared with exercise alone, across 24 studies of 1079 people; blood levels of the brain-plasticity marker BDNF did not change.

    ⚠What it shows: Credible but modest: pooled from 24 studies of 1079 older adults, some with mild cognitive impairment, and the extra benefit over exercise alone was small. The authors themselves flag limitations in the underlying studies, so treat the size of the effect loosely.Review · Healthcare (Basel)

    Full breakdown →Executive function explained →Effects of Combined Exercise Interventions on Cognition in Older Persons: A Systematic Review and Meta-Analysis. Healthcare (Basel) 2026
19. Supplementswell supported · human dataAdded 28 August 2026

    Pomegranate trims blood pressure and cholesterol, but the effects are small

    Pomegranate supplementation modestly reduced body weight, BMI, systolic and diastolic blood pressure, fasting glucose and total cholesterol, and raised HDL, across 53 randomised trials in 2306 people; LDL, triglycerides, HbA1c, waist measures and insulin resistance did not change.

    ⚠What it shows: Real but small: results pooled from 53 trials in 2306 people show statistically clear yet modest shifts, and several key markers, including LDL and triglycerides, did not move at all. The authors call for longer and larger trials before firm conclusions.Meta-analysis · Nutr Metab Cardiovasc Dis

    Full breakdown →Metabolic syndrome explained →Heart Age Calculator →Impacts of supplementation with pomegranate on cardiometabolic risk factors: A systematic review and dose-response meta-analysis. Nutr Metab Cardiovasc Dis 2025
20. Supplementswell supported · human dataAdded 28 August 2026

    CoQ10 shifts blood sugar and triglycerides in type 2 diabetes, not cholesterol

    In people with prediabetes or type 2 diabetes, CoQ10 supplementation significantly reduced triglycerides, fasting blood sugar, HbA1c, insulin resistance and the inflammation marker C-reactive protein, and raised HDL, across 20 randomised trials; total cholesterol, LDL and blood pressure did not change.

    ⚠What it shows: Encouraging but not the final word: results pooled from 20 trials in people with prediabetes or type 2 diabetes, and the trials disagreed with each other on how big the benefits were. The authors want longer studies across a range of doses before firm conclusions.Meta-analysis · BMC Pharmacol Toxicol

    Full breakdown →Insulin sensitivity explained →Metabolic Fitness Index →The effect of CoQ10 supplementation on cardiovascular risk factors in patients with prediabetes and type 2 diabetes mellitus: a grade-assessed systematic review and dose-response meta-analysis. BMC Pharmacol Toxicol 2026
21. Supplementswell supported · human dataAdded 28 August 2026

    Green coffee extract lowers blood sugar so little you would never notice

    A meta-analysis of ten randomised trials found green coffee bean extract lowered fasting blood sugar by 1.791 mg/dl on average, a statistically significant but very small change. Insulin did not improve overall, and only fell significantly in trials using doses of at least 400 mg per day.

    ⚠What it shows: Real but trivial: pooled from ten trials, the blood sugar drop was under two points, far too small for anyone to feel. On insulin the trials disagreed sharply, and the promising result came only from a subgroup taking at least 400 mg a day.Meta-analysis · Phytother Res

    Full breakdown →Insulin sensitivity explained →The influence of green coffee bean extract supplementation on blood glucose levels: A systematic review and dose-response meta-analysis of randomized controlled trials. Phytother Res 2020
22. Women's Healthwell supported · human dataAdded 28 August 2026

    Exercise eases postpartum depression, and there is a sweet spot for how much

    Pooled results from 17 trials in 2,865 postpartum women show aerobic exercise reduced depressive symptoms and improved quality of life, with modelled benefits peaking near 570 MET minutes per week for depression and 420 for quality of life. Anxiety did not significantly improve.

    ⚠What it shows: Solid pooled evidence from 17 trials in 2,865 women, with the biggest mood gains in those who were depressed to begin with. The ideal dose figures come from statistical models rather than head to head comparisons, and anxiety did not improve at all.Meta-analysis · Front Public Health

    Full breakdown →Health-related quality of life (HRQoL) explained →Optimal dose of aerobic exercise for improving postpartum depression, anxiety, and quality of life: a meta-analysis of randomized controlled trials and dose-response analysis. Front Public Health 2026
23. Trainingwell supported · human dataAdded 28 August 2026

    Lifting after 50 improves how fully the brain switches muscle on

    Pooled results from 27 randomised trials in adults aged 50 and over found that resistance training increased voluntary activation, a measure of how fully the nervous system recruits a muscle, with the clearest signal in the plantar flexors and in healthy participants. Muscle electrical activity during maximal effort and antagonist coactivation did not change.

    ⚠What it shows: Reasonably solid: results pooled from 27 randomised trials in adults aged 50 and over, and the activation finding survived when only the best-quality trials were counted. Most participants were healthy older adults, so it is unclear whether the same holds for people with sarcopenia or age-related frailty.Meta-analysis · Exp Gerontol

    Full breakdown →Sarcopenia explained →Strength Standards →The influence of resistance training on neuromuscular function in middle-aged and older adults: A systematic review and meta-analysis of randomised controlled trials. Exp Gerontol 2021
24. Cardiopreliminary · human dataAdded 28 August 2026

    Mostly easy, sometimes brutal: polarised training won the time trials

    In endurance athletes with more than 2 years of training experience, pooled results from 3 randomised trials showed a moderate advantage for polarised training, mostly easy work with a small share very hard, over threshold training for time-trial performance. Only 4 trials met the inclusion criteria in total.

    ⚠What it shows: Suggestive rather than settled: only 4 randomised trials qualified and just 3 had data that could be pooled, all in trained endurance athletes. Those trials scored 4 or 5 out of 10 for methodological quality, which is modest, and time-trial performance was the only outcome with enough data to combine.Meta-analysis · J Strength Cond Res

    Full breakdown →Zone 2 explained →Heart Rate Zone Calculator →Polarized vs. Threshold Training Intensity Distribution on Endurance Sport Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Strength Cond Res 2019

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