Browse the evidence

Quercetin glucosides from onions have higher bioavailability and absorption rates than quercetin aglycones or rutinosides (from tea/apples) due to active transport mechanisms.

If you are seeking quercetin for health benefits, onions may be a more efficient source than tea or apples because your body absorbs the quercetin from onions better. The chemical form attached to sugar in onions allows for active absorption.

Selenium intake exhibits extreme variability based on soil geology and plant species, making it difficult to define a single optimal intake level without considering specific health contexts and selenium species.

Do not assume a standard selenium supplement dose is optimal for you. Your selenium needs depend heavily on where your food is grown (soil content), what type of selenium it is (e.g., selenomethionine vs. selenite), and your specific health conditions. If you live in a low-selenium region or have specific health risks, consult a professional to determine if you need more, less, or no supplementation, as both deficiency and toxicity are possible.

Maternal vitamin B12 deficiency combined with high folate status during pregnancy programs offspring for increased adiposity and insulin resistance by age 6.

For pregnant women, ensuring adequate Vitamin B12 is as critical as folate. In populations with high vegetarianism or low B12 intake, high-dose folic acid supplementation without B12 correction may potentially increase the child's risk of metabolic issues like insulin resistance. Prioritize B12 status alongside folate.

High maternal erythrocyte folate concentrations during pregnancy are associated with increased offspring adiposity (fat mass and body fat percentage) at 6 years, independent of birth weight.

Monitor maternal folate levels. While folate is essential, extremely high levels in the context of B12 deficiency may contribute to offspring adiposity. Ensure a balanced intake rather than excessive supplementation.

Resveratrol exhibits low oral bioavailability of the free compound in humans, with plasma concentrations of free resveratrol remaining below 10 ng/mL (<40 nM) even after high-dose supplementation, while metabolites reach significantly higher concentrations.

If you take resveratrol supplements, do not expect high levels of the raw compound in your bloodstream. The body rapidly metabolizes it into other forms. While the free form is low, the total amount of resveratrol-related compounds in your blood is significant, suggesting the benefits may come from these metabolites or their conversion in tissues, not just the pill itself.

The Residual Method of energy adjustment is the most effective practical tool for correcting misreporting bias in micronutrient intake data derived from food records and 24-hour recalls.

When analyzing dietary data from self-reports, do not simply delete people who report low calories. Use the 'Residual Method' of energy adjustment to statistically correct the micronutrient values. This provides a more accurate picture of true intake than exclusion.

High levels of dietary trypsin inhibitors in raw soybeans and legumes significantly reduce protein and amino acid digestibility (by up to 50%) and protein quality (by up to 100%) in animal models due to pancreatic hypertrophy and endogenous amino acid loss.

If you eat soybeans, kidney beans, or other legumes, ensure they are properly cooked (boiled, autoclaved, or roasted). Raw or under-processed legumes contain trypsin inhibitors that can block protein digestion and reduce nutrient absorption by up to 50%. Processing inactivates these inhibitors, making the protein much more available to your body.

Tannins in sorghum and legumes reduce protein and amino acid digestibility by binding to proteins and precipitating them, with reductions of up to 23% observed in animal models.

If your diet relies heavily on sorghum or tannin-rich legumes like fababean, be aware that tannins can reduce protein absorption by up to 23%. Processing methods like dehulling, soaking, or germination can help reduce tannin levels and improve protein digestibility.

In healthy adult men, dietary alpha-linolenic acid (ALNA) is converted to eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA), but conversion to docosahexaenoic acid (DHA) is severely restricted or absent.

If you rely on plant sources like flaxseed or walnuts for your omega-3s, know that your body converts them to EPA and DPA, but barely makes DHA. To ensure adequate DHA levels, you likely need to consume pre-formed DHA from fish or algae, as your body cannot efficiently make it from plant fats alone.

The biosynthesis of long-chain n-3 polyunsaturated fatty acids (EPA and DHA) from the plant-based precursor alpha-linolenic acid (ALA) is highly inefficient in healthy adults, with only about 0.2% of plasma ALA converting to EPA.

If you rely on plant sources like flax or walnuts for omega-3s, understand that your body converts very little of them into the active forms (EPA/DHA) your brain and heart need. To ensure adequate levels, incorporate direct sources of long-chain n-3 fatty acids, such as fatty fish or algae-based supplements, rather than relying solely on plant precursors.

Low serum 25-hydroxyvitamin D concentrations (specifically <50 nmol/L) are associated with a significantly increased risk of incident all-cause dementia and Alzheimer's disease in elderly adults.

This study suggests that maintaining vitamin D levels above 50 nmol/L may be associated with a lower risk of dementia in older adults. However, it does not prove that taking supplements will prevent dementia. You should discuss your vitamin D levels with your doctor to ensure they are within a healthy range for your overall health, but do not expect supplements alone to guarantee cognitive protection.

Standard BMI cutoffs (≥30 kg/m²) significantly underestimate obesity prevalence, particularly in women, due to failure to account for sarcopenic obesity and body composition changes with age.

If you are a woman, especially over 50, your BMI might be misleading. You could have 'normal weight obesity' (high body fat, low muscle) which carries health risks. Ask your doctor about body composition analysis (like DXA) or leptin levels if you have risk factors, rather than relying solely on BMI.

In elderly populations, malnutrition and antibiotic use drive a decline in gut microbiome diversity and stability, increasing frailty and susceptibility to infection.

For older adults, maintaining a diverse, fiber-rich diet and minimizing unnecessary antibiotic use are crucial for preserving gut health and reducing frailty. Community-dwelling elderly with healthy diets can maintain microbiomes similar to young adults, proving that age itself is not the primary driver of decline.

Systemic amino acid homeostasis is maintained by exchanging essential amino acids for non-essential ones and transferring amino groups from oxidized amino acids to biosynthesis, minimizing net loss through oxidation.

Your body actively recycles amino acids. It swaps essential for non-essential ones and reuses nitrogen from broken-down proteins to make new ones. This minimizes the need to constantly eat protein, though essential amino acids must still be obtained from food.

Vitamin C content in mangoes decreases significantly during ripening and postharvest storage, with levels dropping from high values in green fruit to lower values in ripe fruit.

If you are eating mangoes specifically for their Vitamin C content, choose less ripe fruits or consume them soon after purchase. Vitamin C levels drop significantly as the fruit ripens and during storage, so fresher, less ripe mangoes will provide more of this nutrient.

The gut microbiome plays a critical role in converting unabsorbed flavonoids into bioactive metabolites (e.g., equol from isoflavones, phenolic acids), and the ability to produce these metabolites is a key determinant of health efficacy.

Your gut bacteria determine if certain flavonoids become active. If you don't produce specific metabolites (like equol from soy), you may not get the same benefits as 'producers.' Diversifying your flavonoid sources (anthocyanins, flavonols, etc.) may help ensure you get benefits from compounds your microbiome can process.

Mild mitochondrial uncoupling induces autophagy and mitophagy, which helps clear dysfunctional mitochondria and lipid droplets, potentially improving metabolic health.

Mild stress on mitochondria, such as that induced by exercise or cold, triggers the body's cleanup crew (autophagy). This process removes old mitochondria and fat stores, which is beneficial for metabolic health. This is a natural adaptation to stress, not something to be forced with dangerous chemicals.

Demographic factors, specifically race/ethnicity and age, significantly influence baseline blood mercury levels independent of self-reported consumption, with 'Other' racial/ethnic groups and older women (30-49) having higher concentrations.

Your risk of mercury accumulation depends on your demographics. Women over 30 and those in the 'Other' racial/ethnic category (including Asian, Native American, Pacific Islander) tend to have higher mercury levels than younger women or Mexican Americans, even with similar reported fish intake. Monitor your seafood choices more closely if you fall into these higher-risk groups.

Global dietary calcium and zinc deficiency risks are decreasing but remain highly prevalent, with 3.5 billion and 1.1 billion people at risk respectively in 2011, primarily in Africa and Asia.

Global food systems are currently failing to provide adequate calcium and zinc for billions, particularly in Africa and Asia. While risks are decreasing, they remain high. Individual efforts are insufficient; systemic changes like crop breeding and fortification are necessary.

Laboratory values (e.g., albumin, prealbumin) are poor standalone indicators of nutritional status due to their sensitivity to inflammation and other non-nutritional factors, and should be interpreted within the clinical context.

Do not use albumin or prealbumin levels alone to diagnose malnutrition, especially in acutely ill or inflamed patients. These markers are influenced by disease state and inflammation. Use them as part of a broader assessment including clinical history, physical exam, and functional measures.

Caloric restriction extends life span in model organisms by inducing autophagy, a process essential for clearing damaged organelles and proteins.

Caloric restriction extends life in animals by triggering autophagy, which cleans out damaged cellular parts. While strict dieting is hard to maintain, the paper suggests that pharmacologic agents like rapamycin or spermidine might mimic these benefits by inducing autophagy without the discomfort of starvation. Future research aims to identify safe drugs that activate this recycling process.

Pharmacologic induction of autophagy using rapamycin, resveratrol, or spermidine extends life span in model organisms by mimicking caloric restriction.

Drugs like rapamycin and supplements like spermidine can extend life in animals by triggering cellular cleanup (autophagy). However, rapamycin has significant side effects in mice, and resveratrol's benefits in humans are unclear. Current research aims to find safer drugs that activate this process without the negative health impacts.

Global dietary micronutrient supplies have improved over the last 50 years, but sub-Saharan Africa is the only region where micronutrient density has declined due to a shift toward lower-density staples like rice and maize.

To improve your diet, prioritize foods that are dense in vitamins and minerals (vegetables, fruits, lean meats, legumes) rather than just filling up on empty calories like refined grains or sugars. In regions where staple crops are low in nutrients, diversifying the diet or using fortification is critical.

Saturated fatty acids, particularly palmitate, induce hepatocyte apoptosis via ER stress, JNK activation, and death receptor pathways, while monounsaturated fatty acids (MUFAs) like oleate can be cytoprotective by sequestering palmitate into neutral triglycerides.

The type of fat you eat matters for liver health. High intake of saturated fats (like palmitate) can directly damage liver cells, while monounsaturated fats (like oleate) may help protect the liver by storing toxic fats safely as triglycerides.