Browse the evidence

The presence of the keystone bacterium Ruminococcus bromii is required for the efficient fermentation of resistant starch (specifically RS3) in the human colon; its absence leads to significantly reduced energy recovery from this dietary component.

If you eat resistant starch (like cooled potatoes or high-amylose corn) and don't see the expected gut health or energy benefits, it might be because you lack specific bacteria like Ruminococcus bromii. This bacterium acts as a 'keystone' to break down this starch for your body. While you can't easily buy this specific bacteria as a supplement yet, maintaining a diverse diet high in fibers may support its presence. If you suspect you are a 'low responder' to resistant starch, this microbial factor is a likely biological cause.

Excessive intake of certain minerals (e.g., sodium, iron) can disrupt homeostasis and cause toxic side effects, while severe shortages lead to deficiency diseases.

Do not megadose minerals. Stick to recommended dietary allowances unless advised otherwise by a doctor. High sodium and iron intakes carry specific risks like hypertension and liver damage.

Antinutritional factors like phytic acid and oxalates in plant foods can bind minerals (calcium, magnesium, zinc, iron), reducing their bioavailability and leading to deficiencies.

If you eat a lot of grains and legumes, consider soaking or fermenting them to reduce phytic acid and oxalates, which can block mineral absorption.

Vitamin D supplementation is probably linked to a decrease in dental caries in children and a decrease in parathyroid hormone concentrations in patients with chronic kidney disease requiring dialysis.

For children, Vitamin D supplementation may help reduce tooth decay. For patients with chronic kidney disease on dialysis, it may help lower parathyroid hormone levels. These are probable benefits, but they do not apply to the general population.

Dietary polyphenols reduce the risk of cardiovascular diseases (CVDs) by inhibiting LDL oxidation, preventing platelet aggregation, and improving endothelial function through nitric oxide signaling.

Include polyphenol-rich foods like tea, coffee, berries, and dark chocolate in your diet to support heart health. These foods help protect LDL from oxidation and improve blood vessel function, reducing cardiovascular risk.

Marine n-3 supplementation may offer greater cardiovascular benefits for Black participants and those with low fish consumption.

If you are Black or eat very little fish, you might get more cardiovascular benefit from fish oil supplements than the average person. However, this is a hypothesis-generating finding and not definitive.

Among women who have had a myocardial infarction, low-dose ALA supplementation (2g/day) may reduce the rate of major cardiovascular events, approaching statistical significance.

For women who have had a heart attack, taking 2g of ALA (plant-based n-3) daily might offer some protection against future cardiovascular events, although the evidence is not definitive. This should not replace standard medical care.

Higher estimated potassium excretion is associated with a reduced risk of death and major cardiovascular events compared to lower potassium excretion (<1.50 g/day).

Ensure adequate potassium intake, as higher levels are associated with lower cardiovascular risk. This can be achieved through a diet rich in fruits and vegetables.

Vitamin D insufficiency is prevalent in European populations, particularly in winter and among the elderly, with levels often falling below the threshold for optimal bone and muscle health.

If you live in Europe, especially in winter or if you are elderly, your Vitamin D levels are likely insufficient. This is common due to limited sun exposure and skin synthesis capacity. Consider monitoring levels and supplementing, as standard dietary intake is often insufficient.

Adequate dietary selenium intake is essential for optimal immune function, particularly enhancing T-cell proliferation, NK cell activity, and antibody responses, with the strongest benefits observed when correcting selenium deficiency rather than supplementing already sufficient levels.

If you live in a region with low soil selenium (parts of China, Europe, NZ) or have dietary restrictions, getting enough selenium (55-75 mcg/day) is crucial for a robust immune system, especially as you age. However, if you already eat a varied diet with Brazil nuts, seafood, or meat, extra selenium supplements likely offer no additional immune benefit and may carry risks. Focus on food sources first.

Vitamin E supplementation (800 IU/day) significantly reverses steatohepatitis and reduces hepatic steatosis and ALT in non-diabetic patients, but long-term safety concerns exist.

Non-diabetic NAFLD patients may benefit from 800 IU/day Vitamin E to improve liver health, but should be aware of potential long-term risks.

Higher dietary and supplemental intakes of folate and vitamin B6 are associated with a significantly reduced risk of coronary heart disease (CHD) in women, with the greatest benefit observed when intakes exceed current Recommended Dietary Allowances (RDA).

For women looking to support heart health, aiming for higher intakes of folate and vitamin B6 than the minimum RDA may be beneficial. This can be achieved through a diet rich in leafy greens, fortified cereals, and legumes, or by using multiple vitamin supplements. The study suggests that intakes above 400 µg/d for folate and 3 mg/d for vitamin B6 are associated with the lowest risk of coronary heart disease.

Dietary supplement use, particularly multivitamins and calcium-containing antacids, contributes significantly to total nutrient intake in US adults and must be accounted for in epidemiological studies to avoid confounding.

If you take supplements, especially multivitamins or calcium antacids, they significantly impact your nutrient intake. Researchers and health professionals must account for this when assessing your diet, as ignoring supplements can lead to incorrect conclusions about your health and nutritional status.

Calcium-containing antacids are a significant source of supplemental calcium for many adults, often exceeding the intake from dedicated calcium supplements.

If you take antacids for heartburn, you are likely getting supplemental calcium. This contributes to your total calcium intake and should be considered when assessing your health, especially regarding bone health.

Fermentation and germination of cereals and legumes improve nutritional value by activating endogenous enzymes (e.g., phytase, alpha-amylase) that degrade antinutritional factors (phytates, trypsin inhibitors) and break down complex matrices, thereby increasing the bioavailability of minerals, proteins, and phytochemicals.

To maximize nutrient absorption from grains and legumes, prioritize fermented (e.g., sourdough, tempeh) or germinated (sprouted) versions over unprocessed ones. These processing methods activate enzymes that break down antinutrients like phytates, freeing up minerals and proteins for your body to use.

Adding protein to carbohydrate beverages during endurance exercise does not improve performance but suppresses markers of muscle damage and reduces feelings of muscular soreness.

If you are doing long endurance events, stick to carbohydrates for fuel. You can add a small amount of protein (0.25 g/kg/hour) to help reduce muscle soreness the next day, but do not expect it to make you faster or last longer.

Orlistat improves cardiovascular risk factors, including reducing the incidence of type 2 diabetes and improving lipid profiles, despite causing gastrointestinal side effects.

Orlistat not only aids weight loss but also significantly reduces the risk of developing type 2 diabetes in obese individuals with impaired glucose tolerance. It also improves cholesterol and blood pressure. However, users must manage gastrointestinal side effects, which are common but not necessarily dangerous.

Quercetin aglycone supplementation at doses of 500 mg or higher significantly reduces blood pressure in individuals with stage 1 hypertension, whereas it has no significant effect on normotensive or pre-hypertensive individuals.

If you have Stage 1 hypertension, taking 500 mg or more of quercetin aglycone daily may help lower your blood pressure by a few mmHg. However, if your blood pressure is already normal, this supplement is unlikely to provide cardiovascular benefits. Consult your doctor before starting, especially if you are on medication.

Inulin-type fructans enhance the absorption of calcium and magnesium, with oligofructose-enriched inulin being the most effective product.

Include foods like chicory root (inulin/oligofructose), onions, garlic, and bananas in your diet to support calcium and magnesium absorption. Look for products enriched with oligofructose for potentially better results.

Brazil nuts are an exceptionally high but highly variable source of selenium that may also deliver toxic levels of barium and radium, posing health risks if consumed regularly as a primary selenium source.

If you eat Brazil nuts for selenium, limit your intake. A few nuts can provide enough selenium but may also deliver toxic levels of barium and radioactive radium. Do not rely on them as your sole source of selenium; rotate with other foods like seafood or meat, which have more predictable selenium levels and fewer toxic co-contaminants.

Selenium supplementation can reduce the risk of specific cancers (prostate, colorectal, lung) and improve immune function and cognitive health, but the benefits are highly dependent on baseline selenium status and the form of selenium used.

If you are considering selenium supplements for cancer prevention or immune support, get your selenium status tested first. If you are deficient, supplementation (100-200 mcg/day) may offer benefits, particularly for prostate and colorectal cancer risk. If you are already sufficient, the benefits are less clear, and you may be exposing yourself to unnecessary risks. Consult a healthcare provider to determine if supplementation is right for you.

High dietary fiber intake is associated with reduced mortality from infectious and respiratory diseases, likely mediated by gut microbiota fermentation into anti-inflammatory short-chain fatty acids.

Aim to increase your daily dietary fiber intake by 10 grams. This simple change is associated with a significant reduction in mortality from infectious and respiratory diseases. Focus on plant-based sources like vegetables, fruits, nuts, seeds, and whole grains.

Higher muscle mass (lean/fat-free mass) significantly increases serum and urinary creatinine levels, whereas serum cystatin C levels remain unaffected by muscle mass variations.

If you have high muscle mass, your standard blood test for kidney function (creatinine) will likely read higher than average, even if your kidneys are healthy. This can lead to false alarms. If you are muscular, ask your doctor to use Cystatin C for a more accurate assessment of your kidney health, as it is not skewed by your muscle mass.

Fish oil supplements provide a statistically significant but modest reduction in systolic blood pressure (2.3 mmHg) in adults with hypertension.

Taking fish oil supplements containing omega-3 fatty acids (EPA and DHA) can lower systolic blood pressure by about 2.3 mmHg. While the effect is smaller than lifestyle changes, it is a statistically significant benefit. Supplements were taken several times a day, with doses ranging from 0.1 to 17 grams per day.