Browse the evidence

Combining Vitamin D3 with Calcium increases the risk of kidney stones (nephrolithiasis), and active forms of Vitamin D (alfacalcidol and calcitriol) increase the risk of high blood calcium (hypercalcaemia).

Be cautious with combinations. Taking Vitamin D3 along with Calcium supplements may slightly increase your risk of kidney stones. Additionally, active forms of Vitamin D (alfacalcidol and calcitriol) carry a higher risk of causing high blood calcium levels. These risks are statistically significant but should be weighed against potential benefits, especially if you have a history of kidney stones.

Moderate alcohol consumption (6–48 g/day) is associated with a significantly reduced risk of developing type 2 diabetes compared to abstainers, exhibiting a U-shaped relationship where heavy consumption (>48 g/day) offers no such benefit.

If you do not drink, this evidence does not recommend you start. However, if you already consume alcohol moderately (up to ~48g/day, roughly 1-4 drinks depending on the beverage), this meta-analysis suggests you may have a lower risk of developing type 2 diabetes compared to those who abstain completely. Heavy drinking (>48g/day) eliminates this benefit. Note that this is observational data; lifestyle factors like physical activity and weight management remain the primary drivers of diabetes risk.

Oral butyrate supplementation reduces appetite and prevents diet-induced obesity primarily by activating the gut-brain neural circuit (vagal nerve) to suppress orexigenic neurons and increase sympathetic outflow to brown adipose tissue.

Oral butyrate supplementation (specifically sodium butyrate mixed into a high-fat diet at 5% weight/weight in this study) reduces food intake and prevents obesity in mice. The key is that it must be taken orally to trigger the gut-brain-vagus nerve pathway; injecting it does not work. It works by suppressing hunger signals in the brain and activating brown fat to burn energy. For humans, this suggests that dietary sources of butyrate (like fiber fermentation) or oral supplements might help manage appetite and weight, but the exact effective dose and long-term safety in humans require further clinical validation.

Increased exposure to media content related to weight gain, diet culture, and pandemic stress, combined with increased use of video-conferencing, increases eating disorder risk by heightening body image concerns and social comparison.

Be mindful of your media consumption, especially on social media. Limit exposure to content that promotes thin ideals or diet culture. If you use video-conferencing, try to focus on the conversation rather than your appearance, and take breaks from screens to reduce body image preoccupation.

Fears of contagion and health concerns related to the pandemic can increase eating disorder risk by promoting restrictive diets focused on immunity or avoiding foods perceived as contaminated.

Avoid restrictive diets based on fear of contamination. Focus on a balanced diet that supports your immune system. If you have health anxiety, seek professional support to manage your fears and eating behaviors.

Dietary arachidonic acid (ARA) supplementation improves cognitive function in elderly individuals with low baseline serum ARA levels and enhances visual acuity and cognitive development in preterm infants when added to formula.

If you are elderly and have low arachidonic acid levels, or if you are feeding a preterm infant, ensuring adequate ARA intake (via diet or supplementation) is critical for cognitive and visual development. For the general healthy adult, ARA is an essential component of cell membranes and brain function, so avoiding it is unnecessary and potentially detrimental.

Glutathione peroxidase 4 plays a crucial role in male fertility by acting as an anti-oxidative enzyme and serving as a structural component of the sperm midpiece.

For men concerned with fertility, maintaining adequate selenium levels is important for sperm structure and antioxidant defense. This is one specific benefit among many selenium provides.

Total energy intake acts as a primary determinant of disease risk and serves as a critical confounder in nutritional epidemiology because nutrient intakes are positively correlated with total energy consumption.

When analyzing diet or health outcomes, do not look at specific nutrients in isolation. Total energy intake is a primary determinant of disease and confounds the relationship between specific nutrients and health. You must account for total calories to understand the true impact of dietary composition.

College students significantly overestimate the prevalence of risky health behaviors among their peers, including alcohol use, cigarette use, sexual activity, and drug use.

You likely underestimate how many of your peers are making healthy choices. Most students do not drink heavily, smoke, or engage in risky sexual behavior as frequently as it seems. Trust your own healthy choices; you are part of the majority.

Conjugated Linoleic Acid (CLA) shows potent anti-carcinogenic and anti-lipogenic effects in animal models, but human evidence is currently insufficient to confirm these benefits at typical dietary intakes.

Do not rely on CLA supplements for fat loss or cancer prevention based on current evidence. The doses required to see benefits in animals are much higher than what humans typically eat or can safely supplement. Focus on whole foods like dairy and meat which contain natural CLA, but do not expect therapeutic effects from supplementation.

Higher urinary concentrations of specific phthalate metabolites (MBzP, MEHHP, MEOHP, MEP) are associated with increased waist circumference, and higher concentrations of MBP, MBzP, and MEP are associated with increased insulin resistance (HOMA) in adult U.S. males.

This study suggests that common environmental chemicals (phthalates) may contribute to belly fat and insulin resistance in men. While you can't eliminate all exposure, you can reduce it by avoiding plastic food containers, heating food in plastic, and choosing products with fewer fragrances (where some phthalates are found). However, focus primarily on proven factors: maintain a healthy weight, exercise regularly, and eat a balanced diet, as these have a much larger impact on your metabolic health.

In adult critically ill patients, providing higher energy intake (up to 30 kcal/kg/day) compared to lower intake (down to 300 kcal/day) does not significantly improve clinical outcomes such as mortality, length of stay, or infection rates.

For critically ill adults in the ICU, aim for 12-25 kcal/kg/day during the first 7-10 days. Do not aggressively push for higher calories, as studies show no benefit over lower doses and potential risks like hyperglycemia. Monitor blood sugar and triglycerides closely.

Blueberry consumption improves cognitive function and slows cognitive decline in older adults, particularly those with mild cognitive impairment.

If you are concerned about memory or cognitive decline, adding blueberries to your diet may help. Studies suggest that eating blueberries daily for several months can improve memory and executive function, especially in older adults.

Performance-enhancing drug (PED) use, particularly anabolic-androgenic steroids (AAS), is associated with a wide variety of severe adverse health effects including cardiovascular, psychiatric, metabolic, endocrine, neurologic, infectious, hepatic, renal, and musculoskeletal disorders, as well as an increased risk of death.

If you are using performance-enhancing drugs, especially anabolic steroids, you are at significant risk for serious health problems including heart disease, liver damage, hormonal imbalances, and even death. The doses used are far higher than what the body naturally produces, and combining them with other drugs increases these risks. This is not just an issue for athletes; it affects a large number of non-athletes as well. Seek medical advice if you are using these substances.

For prediabetes prevention, neither exercise nor drug interventions show statistically significant mortality benefits compared to control or each other.

Current evidence does not show that exercise or drugs significantly reduce mortality risk in people with prediabetes. Focus on other proven health benefits of exercise (e.g., functional capacity, muscle strength) rather than mortality prevention for this specific group.

Small molecule-based therapies and reprogramming strategies can ameliorate or reverse aging-related conditions by manipulating epigenetic mechanisms.

Epigenetic rejuvenation therapies are being developed. Consult a healthcare provider for emerging treatments.

Dietary fiber fermentation outcomes (SCFA profile and quantity) are determined by the host's gut microbiota enterotype (Prevotella- vs. Bacteroides-dominated), meaning identical fiber substrates produce different health-relevant metabolites depending on individual microbiome composition.

If you are trying to optimize gut health with fiber, recognize that your unique gut bacteria dictate the outcome. A fiber that boosts satiety-signaling propionate in one person might produce different effects in another. Personalized fiber choices based on microbiome testing may be necessary for specific health goals, as generic fiber advice ignores these biological differences.

Activation of the Nrf2 signaling pathway promotes mitochondrial biogenesis, thereby supporting active longevity and mitigating age-related mitochondrial dysfunction.

To support active longevity, engage in activities that mildly stress the body, such as moderate physical exercise. This stress activates the Nrf2 pathway, which in turn boosts mitochondrial biogenesis (the creation of new mitochondria) and improves cellular energy efficiency. This process helps counteract age-related decline in mitochondrial function.

Nrf2 and PGC-1α form a bidirectional regulatory loop where Nrf2 influences PGC-1α expression, and PGC-1α activates Nrf2, jointly regulating mitochondrial biogenesis.

Understanding that Nrf2 and PGC-1α work together helps explain why both stressors (like exercise) and nutrients (like those activating Nrf2) are important for mitochondrial health. They reinforce each other.

Shift work, particularly night shift work involving exposure to light at night, is associated with an increased risk of breast cancer.

Women who work night shifts have a higher risk of breast cancer, likely because artificial light at night suppresses melatonin. If you work nights, minimizing light exposure during work hours and ensuring total darkness during daytime sleep may help mitigate this risk.

Dietary patterns identified by reduced rank regression (RRR) as being statistically significantly associated with inflammatory biomarkers are almost all meat-based or 'Western' patterns.

If you are looking at dietary patterns derived from statistical models like RRR, expect them to highlight meat and refined grains as key drivers of inflammation. This reinforces the importance of limiting these foods.

Serum estrone (E1) and estradiol (E2) are positively associated with bone mineral density (BMD) in elderly men, independent of testosterone levels.

Elderly men should understand that estrogen (derived from testosterone) is vital for bone health. Low estrogen levels, even if testosterone is normal, can contribute to bone loss. Monitoring bioavailable estrogen may be as important as testosterone for preventing osteoporosis in aging men.

Activation of the bile acid receptor FXR using agonists like Obeticholic Acid (OCA) improves liver histology (NAFLD Activity Score and fibrosis) in patients with NASH, though it may negatively impact lipid profiles by increasing LDL and decreasing HDL cholesterol.

If you have NASH, your doctor might prescribe Obeticholic Acid (25mg daily) to improve liver scarring and inflammation. Be aware that this medication often raises LDL cholesterol and lowers HDL, so your lipid levels will need close monitoring. It resolves NASH in about 1 in 5 patients, so it is not a guaranteed cure but a tool to manage disease progression.

Activation of the bile acid receptor TGR5 (GPBAR1) increases energy expenditure and thermogenesis in brown adipose tissue and muscle, and stimulates GLP-1 release to improve glucose tolerance.

Bile acids that activate TGR5 (like those from certain diets or supplements) may help burn more energy and improve blood sugar control by stimulating GLP-1. However, specific TGR5-targeted drugs are still in development and not yet standard care.