Medical claims, health myths, and wellness advice tested against the evidence.

Current evidence does not support cannabis as an effective treatment for anxiety and depression, with studies showing it is associated with worsening of these conditions in many users. While some individuals report symptom relief, controlled trials have failed to demonstrate therapeutic efficacy comparable to established treatments.

Studies show an association between fluoride exposure and lower IQ scores in children, but this relationship is primarily observed at levels above 1.5 mg/L, which exceeds the recommended water fluoridation level of 0.7 mg/L. The evidence at recommended levels remains mixed, with some studies showing no effects and others suggesting small decreases when accounting for total fluoride exposure from all sources.

GLP-1 drugs like Ozempic do cause muscle loss — typically 20-40% of total weight lost is lean mass. However, this is comparable to or less than muscle loss from calorie restriction or bariatric surgery. The clinical significance depends on the patient: for older adults or those with low baseline muscle, this is a genuine concern requiring monitoring and resistance training.

Recent genetic and observational studies consistently show that moderate alcohol consumption is associated with increased cardiovascular disease risk, not protection. The apparent protective effect seen in older studies was due to comparing moderate drinkers with a control group that included former heavy drinkers who had quit due to health problems.

Raw milk is associated with 150-fold higher rates of foodborne illness compared to pasteurized milk, with multiple documented outbreaks causing hospitalizations and deaths. While some studies link raw milk consumption to reduced allergies and asthma in children, these are observational findings that don't establish causation.

Continuous glucose monitors show promise for helping non-diabetics personalize their diet and lifestyle choices, but research has not demonstrated clear health improvements in metabolically healthy people. Most evidence supporting CGM benefits comes from studies of people with diabetes or prediabetes, not healthy individuals.

Multiple controlled trials found that replacing saturated fats with seed oils reduced heart disease risk by 13-19% and lowered inflammation markers. No controlled trial has shown seed oils alone cause harm when separated from ultra-processed food.

Sperm counts and testosterone levels have shown substantial declines of 50-60% in Western populations since the 1970s according to multiple large-scale analyses. However, the data comes primarily from industrialized nations and the clinical significance remains debated since most men's levels remain above subfertility thresholds.

Ultra-processed foods show some addiction-like properties through dopamine pathways and behavioral patterns, but current evidence indicates they are less addictive than cigarettes which cause severe physical dependence through nicotine. The comparison overstates the similarity given cigarettes' well-established withdrawal syndromes, specific receptor mechanisms, and higher treatment resistance.

Chemical sunscreens are associated with endocrine disruption in laboratory studies and show concerning systemic absorption in humans, but their proven skin cancer prevention benefits currently outweigh theoretical risks. The evidence for human harm remains limited to biomonitoring data and animal studies, while melanoma prevention is documented in randomized controlled trials.

Studies show melatonin supplements at low doses (0.5-6mg) are associated with minimal adverse effects in trials lasting up to 24 months, though quality control issues and inconsistent product labeling are documented concerns. However, comprehensive data on cardiovascular safety beyond 2 years remains limited, with one large observational study finding associations with increased heart failure hospitalizations in long-term users.

Multivitamins show no mortality benefit and may be associated with a small increased mortality risk in some meta-analyses, though they demonstrate specific benefits like 8% cancer reduction in men and prevention of nutritional deficiency diseases. The evidence is mixed, with confounding factors making it difficult to establish clear causal relationships between multivitamin use and mortality outcomes.

An 8-hour eating window was associated with a 91% higher risk of cardiovascular death in a large observational study. However, this finding comes from self-reported dietary data that cannot establish causation, and short-term controlled trials show cardiovascular benefits from time-restricted eating.

While alcohol consumption at any level is associated with increased cancer and injury risks, observational studies consistently show light-to-moderate drinking (1-2 drinks/day) is associated with reduced cardiovascular disease and all-cause mortality compared to abstinence. However, methodological limitations like the sick-quitter effect and healthy user bias may overstate these protective associations.

Microplastics have been detected in human brain tissue at growing concentrations and animal studies show neurological effects, but no human studies have yet established that these particles cause serious health problems. The evidence remains limited to observational findings and animal models, with ethical constraints preventing the controlled human studies needed to prove causation.

When total daily calories are held constant, eating late at night does not cause more weight gain than eating the same calories during the day. However, real-world late-night eating is associated with higher total calorie intake and poorer food choices, which do lead to weight gain.

The claim that a daily glass of wine is good for health is contradicted by strong evidence showing alcohol increases cancer risk by 10-15% and is classified as a Group 1 carcinogen by WHO. While some studies show cardiovascular benefits in older adults, meta-analyses of millions of people demonstrate that alcohol's health risks outweigh any benefits at the population level.

Artificial sweeteners are associated with gut microbiome changes and metabolic issues in some studies, but causation remains unclear due to confounding factors and inconsistent results across research. The strongest evidence comes from observational studies rather than controlled trials, and effects appear dose-dependent with typical consumption showing minimal impact.

Prolonged desk sitting is associated with increased health risks including higher mortality rates, but these risks can be substantially reduced through 60-75 minutes of daily moderate-to-vigorous exercise. The evidence comes primarily from observational studies in affluent, health-conscious populations, which may not apply equally to all demographic groups.

Current evidence suggests psilocybin therapy may have larger effect sizes than traditional antidepressants in some depression studies, though direct comparisons remain limited. However, the vastly smaller evidence base, accessibility barriers, and unknown long-term safety profile prevent establishing true superiority over medications tested in millions of patients.