Evidence reviews on overall wellness and prevention.
47 claims reviewed
Overwhelming scientific evidence from millions of children confirms no link between vaccines and autism. The original 1998 Wakefield study was retracted for fraud. Multiple large-scale studies across different countries consistently demonstrate vaccine safety.
Very weak evidence supports activated charcoal for general body detoxification. While medically effective for acute poisoning within 1-2 hours of ingestion, no credible evidence supports routine charcoal supplementation for removing everyday toxins, heavy metals, or metabolic waste. The detox marketing claims lack biological plausibility for systemic toxin removal.
Moderate evidence supports acupuncture for chronic pain relief, particularly for back pain, knee osteoarthritis, and headaches. Effect sizes are small to moderate, and separating true physiological effects from enhanced placebo response remains challenging.
Individual patient data meta-analyses show acupuncture provides statistically significant pain relief beyond placebo (sham acupuncture), but the effect size is modest. The clinical meaningfulness of acupuncture's advantage over sham remains debated.
Moderate evidence supports acupuncture for chronic pain conditions, with effects modestly superior to sham acupuncture and substantially superior to no treatment. The small difference between real and sham acupuncture suggests non-specific effects (therapeutic ritual, expectation) contribute significantly to outcomes.
Strong evidence from global burden of disease analyses and natural experiments demonstrates that ambient air pollution (particularly fine particulate matter PM2.5) significantly shortens life expectancy, contributing to an estimated 8.8 million excess deaths annually worldwide.
Weak evidence from observational studies suggests an association between nighttime light exposure and breast/prostate cancer risk, possibly mediated by melatonin suppression. However, no causal RCTs exist and confounding from shift work, sleep disruption, and lifestyle factors is difficult to separate.
Current evidence shows daily aspirin does NOT provide net benefit for primary prevention in healthy people. Modern trials (ASPREE, ARRIVE) demonstrate that bleeding risks outweigh any modest cardiovascular benefit in low-risk populations.
Strong evidence from systematic reviews and large cohort studies demonstrates that breastfeeding provides significant protection against respiratory and gastrointestinal infections in infancy, with dose-response relationships for duration and exclusivity.
Moderate evidence suggests cold water exposure acutely increases dopamine levels by 200-300% above baseline. However, evidence comes primarily from a single well-cited study, and long-term effects on tonic dopamine levels are unestablished.
Despite being widely recommended, the evidence supporting flossing for gum disease prevention is surprisingly weak. Cochrane reviews found only 'unreliable, very low quality evidence' showing a small reduction in gingivitis, with minimal impact on periodontitis or clinical attachment loss.
Moderate evidence supports slow deep breathing for acutely reducing blood pressure by 5-10 mmHg systolic. Device-guided breathing (e.g., RESPeRATE) has FDA clearance, though long-term sustained reductions require consistent daily practice.
Moderate evidence supports an association between poor dental health (particularly periodontal disease) and increased cardiovascular disease risk. Meta-analyses find a 20-35% elevated risk in those with periodontitis, though shared risk factors complicate causal inference.
Conflicting evidence surrounds EMF health effects from consumer devices. Large epidemiological studies and expert reviews find no consistent evidence of harm at typical exposure levels, though some observational studies report associations that remain unexplained and fuel ongoing debate.
Very weak evidence supports Epsom salt baths for muscle soreness. While magnesium sulfate is absorbed transdermally in small amounts, no rigorous clinical trials demonstrate that Epsom salt baths outperform plain warm water baths for recovery. Benefits likely stem from heat and buoyancy rather than magnesium absorption.
Moderate evidence links low serum ferritin to diffuse hair loss (telogen effluvium), particularly in premenopausal women. Iron repletion may improve hair density in deficient individuals, though optimal ferritin thresholds remain debated.
Strong evidence from Cochrane reviews and large observational studies demonstrates that influenza vaccination reduces laboratory-confirmed influenza by 40-60% in matched seasons and significantly reduces influenza-related hospitalizations, though effectiveness varies substantially by season.
Conflicting evidence exists regarding fluoride and cognitive development. High-fluoride exposure (>1.5 mg/L) is associated with lower IQ in some studies, primarily from China and India. However, at US/UK community water fluoridation levels (0.7 mg/L), evidence of cognitive harm is weak and methodologically contested.
Weak evidence with high risk of bias suggests grounding may reduce inflammation markers. Studies are small, poorly controlled, and largely conducted by researchers with commercial interests in earthing products. Claims far exceed the quality of available evidence.
Strong evidence from multiple systematic reviews and landmark intervention trials demonstrates that handwashing with soap reduces respiratory infections by 16-21% and diarrheal diseases by 30-48%, making it one of the most cost-effective public health interventions.
Overwhelming evidence from prospective studies involving over 1 million participants and meta-analyses of treatment trials establishes hypertension as the single strongest modifiable risk factor for stroke, with a continuous dose-response relationship.
Weak evidence: while plants can remove VOCs under sealed laboratory conditions, real-world studies demonstrate that the number of plants needed to meaningfully improve home air quality is impractically large—hundreds to thousands per room—making this claim essentially a myth for typical indoor environments.
HRT is the most effective treatment for menopausal vasomotor symptoms (hot flashes, night sweats), reducing their frequency by 75-90%. This benefit is well-established, though risk-benefit analysis requires individualization based on timing, age, and personal history.
Weak evidence supports contrast hydrotherapy (alternating hot and cold water) for reducing inflammation. While the practice may reduce perceived soreness, objective inflammatory biomarkers show minimal changes in controlled studies.
Weak evidence supports infrared sauna use for heavy metal detoxification. While sweat does contain trace amounts of heavy metals, the quantities are negligible compared to renal excretion, and no clinical trials demonstrate meaningful body burden reduction.
Moderate evidence suggests infrared light therapy accelerates wound healing by enhancing cellular metabolism and collagen synthesis. Results are consistent in animal models but more variable in human trials, with effect sizes depending on wavelength and wound type.
Strong evidence from large RCTs and meta-analyses demonstrates that low-dose aspirin (100-150 mg/day) started before 16 weeks of gestation reduces preeclampsia risk by approximately 50-60% in high-risk pregnancies, though benefit is substantially diminished when started later in pregnancy.
Moderate but inconsistent evidence suggests massage therapy may reduce cortisol levels. Earlier research reported large reductions, but more rigorous recent studies show smaller and sometimes non-significant effects. Measurement methodology significantly impacts results.
No credible scientific evidence supports mewing (tongue posture exercises) changing adult facial bone structure. The practice is promoted by social media influencers and one orthodontist without peer-reviewed clinical trials. Any perceived changes likely reflect soft tissue adaptation, photography angles, or natural maturation.
Moderate evidence suggests chronic mouth breathing is associated with adverse health outcomes including dental problems, sleep-disordered breathing, and craniofacial changes. However, causality is difficult to establish since mouth breathing is often a symptom of underlying nasal obstruction rather than an independent risk factor.
Moderate evidence from large epidemiological studies supports that chronic environmental noise exposure (particularly traffic and aircraft noise above 55 dB) increases risk of hypertension, ischemic heart disease, and stroke through sympathetic nervous system activation and sleep disruption.
Conflicting evidence. The traditional belief that 'poor posture' causes back pain is not well-supported by prospective studies. Systematic reviews find weak and inconsistent associations between spinal curvature or sitting posture and pain outcomes. Psychological factors and physical inactivity may be stronger predictors.
Moderate evidence supports red light therapy (photobiomodulation) for specific applications like wound healing and joint pain, but claims about broader benefits like anti-aging and fat loss remain weakly supported with inconsistent study results.
Moderate evidence from observational studies and emerging RCTs suggests regular sauna use is associated with reduced cardiovascular mortality and improved vascular function. Finnish cohort data shows dose-response benefits, though causality remains unconfirmed due to limited interventional trials.
Moderate evidence suggests excessive screen time is associated with reduced physical activity and poorer health outcomes in children, though effect sizes are generally small and the relationship is more nuanced than a simple displacement model suggests.
Strong evidence from large prospective cohorts and meta-analyses demonstrates that prolonged sedentary behavior (>8 hours/day) increases all-cause mortality by 20-60%, with dose-response relationships. The risk is partially but not fully attenuated by moderate-vigorous physical activity.
Moderate evidence suggests regular hot water immersion acutely improves vascular function and is associated with reduced cardiovascular risk in observational studies, but long-term intervention evidence is limited and short-lived effects may not produce lasting benefit.
Overwhelming evidence from prospective studies involving millions of participants shows that quitting smoking at any age adds years to life expectancy—up to 10 years if cessation occurs before age 40, and substantial gains even at older ages.
Moderate evidence suggests spinal manipulation provides small, short-term improvements in pain and function for acute and chronic low back pain. Effects are statistically significant but clinically modest, comparable to other conservative treatments like exercise or NSAIDs.
Weak evidence suggests standing desks reduce sedentary time but provide minimal caloric benefit (~9 extra kcal/hour). Benefits for back pain are inconsistent, and no studies demonstrate meaningful improvements in long-term health outcomes.
Moderate evidence supports that inability to stand on one leg for 10 seconds in middle-to-older age is associated with higher all-cause mortality, though this likely reflects overall physical capability rather than a specific causal mechanism.
Moderate evidence links sunlight exposure to testosterone levels, primarily through vitamin D synthesis. Seasonal variation in testosterone is well-documented, and vitamin D supplementation in deficient men raises testosterone. Direct UV-to-testosterone pathways remain speculative.
Strong evidence from a landmark 10-year RCT demonstrates that regular sunscreen use reduces melanoma and squamous cell carcinoma incidence. The effect is clearest for squamous cell carcinoma, with growing evidence for melanoma prevention.
Weak evidence suggests tongue scraping temporarily reduces bacterial load and volatile sulfur compounds (halitosis) on the tongue surface, but no studies demonstrate meaningful improvements in overall oral health outcomes like cavity prevention or periodontal disease.
Overwhelming scientific evidence from multiple large-scale studies involving millions of children confirms that vaccines do not cause autism. The original 1998 paper claiming a link was retracted for fraud. Vaccines are safe and effective, with no causal association to autism spectrum disorder.
Overwhelming evidence confirms that seatbelt use reduces crash fatality risk by approximately 40-50% for front-seat occupants. This is one of the most well-established public health interventions, supported by decades of epidemiological data and biomechanical research.
Weak evidence from one landmark study shows Wim Hof method practitioners can voluntarily suppress inflammatory responses to endotoxin injection. However, this does not prove enhanced immunity against infections, and the cold exposure component confounds attribution to breathing alone.