Browse the evidence

High dietary intake of specific carotenoids (alpha-carotene, beta-carotene, lutein/zeaxanthin) and vitamins (A, C) from foods is inversely associated with breast cancer risk in premenopausal women, particularly those with a positive family history or high alcohol consumption.

If you are premenopausal, focus on getting alpha-carotene, beta-carotene, lutein, zeaxanthin, vitamin A, and vitamin C from whole fruits and vegetables rather than supplements. This is especially important if you have a family history of breast cancer or drink alcohol regularly, as the protective association is strongest in these groups. Postmenopausal women without hormone therapy may not see the same benefits from these specific nutrients.

High dietary intake of protein and minerals (specifically potassium, zinc, magnesium, calcium, and phosphorus) is associated with higher plasma levels of Insulin-like Growth Factor I (IGF-I) and the IGF-I:IGFBP-3 molar ratio in middle-aged to elderly men.

To support healthy IGF-I levels, focus on consuming adequate amounts of protein and minerals rather than just total calories. Ensure your diet includes sources of potassium, zinc, magnesium, calcium, and phosphorus. Both animal sources (like fish, poultry, and milk) and plant-based proteins contribute to this effect. Red meat is not uniquely required for this benefit.

Among women with serum 25-hydroxyvitamin D [25(OH)D] concentrations below 50 nM, higher dietary calcium intake is significantly associated with higher total hip bone mineral density (BMD), whereas this association disappears when 25(OH)D levels are above 50 nM.

If you are concerned about bone health, check your vitamin D levels first. For women with low vitamin D (<50 nM), increasing dietary calcium helps bone density. However, if your vitamin D is already sufficient (>50 nM), simply eating more calcium will not further improve bone density. For men, this study found no link between calcium intake and bone density, highlighting vitamin D status as the primary driver for both sexes.

Serum 25-hydroxyvitamin D [25(OH)D] status is the dominant predictor of total hip bone mineral density (BMD) in both men and women, whereas the association between dietary calcium intake and BMD is negligible or non-existent in men and women with adequate vitamin D levels.

For both men and women, maintaining adequate vitamin D levels is the most important factor for bone density. While women with low vitamin D may benefit from higher calcium, men in this study showed no bone density benefit from increased calcium intake regardless of vitamin D levels. Focus on optimizing vitamin D status first.

High dietary intake of calcium (≥800 mg/day) and magnesium (≥300 mg/day) is independently associated with a significantly lower risk of developing hypertension in women compared to low intake.

To support healthy blood pressure, prioritize getting at least 800 mg of calcium and 300 mg of magnesium daily through your diet. Good sources include dairy products, fruits, vegetables, and cereals. While potassium and fiber are healthy, this research suggests they may not independently lower hypertension risk as much as calcium and magnesium do. Managing your weight and limiting alcohol are even more critical factors, but optimizing these minerals is a key dietary step.

Potassium supplementation significantly lowers blood pressure in normotensive individuals with low habitual dietary intake, whereas calcium and magnesium supplements do not.

If you are normotensive but have a diet low in potassium, supplementing with potassium (approx 40 mmol/day) can modestly lower your blood pressure. However, adding calcium or magnesium supplements does not help and may not be necessary. Focus on identifying if your dietary intake is low before supplementing.

Consuming 1 L of fat-free milk daily for 12 weeks significantly increases serum 25-hydroxyvitamin D and decreases parathyroid hormone (PTH) in young women, suggesting a reduction in bone turnover.

To support bone health, ensure you are getting enough calcium and vitamin D. This study suggests that drinking 1 liter of fat-free milk daily can significantly improve vitamin D status and reduce bone turnover markers in young women, even if they were previously vitamin D insufficient.

Increasing whole fruit consumption by ≥7 servings/week over an 8-year period is associated with a reduced risk of incident hypertension, whereas increasing vegetable consumption by the same amount is not significantly associated with reduced risk.

If you want to lower your blood pressure risk by changing your diet, focus on increasing your fruit intake rather than just your vegetable intake. Try adding roughly one extra serving of whole fruit per day to your current diet and maintain that increase over several years. Simply eating more vegetables without increasing fruit may not provide the same protective benefit against hypertension.

Insufficient whole grain intake is the single largest dietary contributor to preventable cancer cases, followed by low dairy intake and high processed meat consumption.

Aim for 3 servings of whole grains daily. This specific factor contributes to the highest number of preventable cancer cases. Ensure at least half of your grain intake is whole grains, as recommended by federal guidelines.

Magnesium supplementation (20 mmol/d for 8 weeks) significantly lowers blood pressure in hypertensive patients, with the magnitude of reduction being greater in those with higher baseline blood pressure.

If you have high blood pressure, taking 480mg of magnesium oxide daily for at least 8 weeks may help lower it slightly, especially if your blood pressure is currently high. It is not a replacement for medication but a supportive lifestyle addition. Monitor your blood pressure to see if you respond, as those with higher starting pressures tend to see more benefit.

Vegan and low-fat dietary patterns, when implemented as intended, mostly align with 2021 AHA Dietary Guidance but face challenges regarding nutrient adequacy and adherence due to severe restrictions.

If you follow a vegan or low-fat diet, it can support heart health, but you must be careful about nutrient adequacy. Work with a registered dietitian to ensure you are getting enough essential nutrients, especially if you exclude animal products or fats.

Low intake of fruits and whole grains are the two most significant individual dietary risk factors for cardiometabolic mortality in the MENA region, accounting for 12% and 11% of deaths respectively.

To significantly reduce heart disease and diabetes risk in the MENA region, prioritize increasing daily consumption of fruits and whole grains. These two specific food groups are responsible for the largest share of preventable deaths among all dietary factors.

Leucine is a critical amino acid that can stimulate muscle protein synthesis, but complete essential amino acids are required for sustained MPS.

While leucine is a key trigger for muscle building, you still need to eat complete proteins containing all essential amino acids. Leucine alone is not enough to sustain muscle growth.

Rapid and substantial weight reduction via GLP-1 therapy increases the risk of nutrient deficiencies and bone density loss, particularly when caloric intake drops below 1200 kcal/day for females or 1800 kcal/day for males without nutritional counseling.

Monitor your caloric intake. If you are eating less than 1200 calories (women) or 1800 calories (men) per day, you must prioritize nutrient-dense foods or consider a multivitamin/mineral supplement to prevent deficiencies in iron, calcium, vitamin D, and B12. Avoid rapid weight loss (>14% in 3-4 months) if possible to protect bone density.

Higher achieved plasma phospholipid omega-3 fatty acid levels (from fish oil supplementation) are associated with a significantly lower risk of major perioperative bleeding.

Higher blood levels of omega-3 fatty acids from fish oil are linked to less bleeding during heart surgery. This suggests that ensuring adequate omega-3 status before surgery might be beneficial, though the primary finding is that fish oil itself is safe.

GLP-1 therapy for obesity increases the risk of nutritional deficiencies (e.g., iron, calcium, vitamins A, D, E, K, B1, B12, C) due to significant reductions in caloric intake and potential GI side effects that impair absorption.

Because GLP-1s make you eat much less, you might not get enough essential vitamins and minerals. Watch for signs like fatigue, hair loss, or poor wound healing. Prioritize nutrient-dense foods (vegetables, lean proteins, whole grains) and discuss with your doctor whether you need specific supplements, especially if your calorie intake is very low.

Polyphenols and unsaturated fats in the Mediterranean diet mitigate metabolic syndrome risk by suppressing proinflammatory cytokines and lipid peroxidation.

Use extra virgin olive oil as your primary fat source. It contains polyphenols that reduce inflammation and improve metabolic health, countering the negative effects of saturated and trans fats found in Western diets.

Obesity is associated with high prevalence of micronutrient deficiencies (e.g., Vitamin D, Iron, B12) due to physiological changes like increased volume of distribution, sequestration in adipose tissue, and inflammation-induced malabsorption (e.g., hepcidin blocking iron).

If you have obesity, assume you may be deficient in key micronutrients like Vitamin D, Iron, and B12, regardless of how much you eat. Focus on nutrient-dense foods and discuss screening with your doctor, as standard weight loss diets can sometimes worsen these deficiencies.

Trans fatty acids (TFAs) from industrial hydrogenation increase coronary heart disease risk and should be avoided, while naturally occurring TFAs from ruminant sources (dairy/meat) show no adverse effect or potential benefit.

Avoid industrially produced trans fats found in partially hydrogenated oils, as they increase heart disease risk. However, you do not need to avoid natural trans fats found in small amounts in dairy and meat, as they do not appear to increase risk and may even be protective.

Lower plasma glycine levels are independently associated with higher BMI and male gender, suggesting glycine is a marker of favorable metabolic health and its reduction is a risk factor for metabolic syndrome.

Low glycine levels are linked to higher BMI and male gender, and may indicate higher metabolic risk. While this paper doesn't prescribe a glycine supplement dose, it highlights glycine as a key marker of metabolic health. Maintaining healthy body weight helps preserve glycine levels, which may support metabolic function.

Adherence to Mediterranean (MedDiet) or MIND diets reduces the risk of cognitive decline and dementia by lowering inflammation and oxidative stress.

Eat more vegetables, fruits, legumes, nuts, and fish. Use olive oil instead of butter. Limit red meat and processed foods. This pattern helps reduce inflammation and supports brain health.

Dietary iodine intake is primarily derived from dairy products in Canadian adults, and public health policies promoting salt restriction and reduced dairy consumption may inadvertently increase the risk of iodine deficiency.

If you are following a low-sodium diet for blood pressure, be aware that you might be consuming less iodine. Dairy products are a major source of iodine in the Canadian diet. Ensure you are getting enough iodine through other sources like fish, eggs, or supplements if you significantly cut back on dairy and salted foods.

Regional variations in iodine status exist in Canada, with residents of Quebec City and Vancouver having significantly lower iodine status compared to those in Hamilton and Ottawa, driven by differences in dietary habits and environmental exposure to inhibitors.

Where you live affects your iodine status. People in Quebec City and Vancouver were found to have lower iodine levels than those in Hamilton and Ottawa. This is likely due to local dietary differences (less dairy/bread) and higher exposure to inhibitors like smoking. Check your local food sources.

HMB-Free Acid (HMB-FA) provides a minor, statistically significant improvement in lower body strength (leg press) compared to HMB-Calcium and placebo, but this effect is likely too small to be practically meaningful for hypertrophy.

HMB-Free Acid might give you a tiny boost in leg press strength compared to the calcium version or placebo, but it won't help you build more muscle or improve upper body strength. The difference is likely too small to matter for your overall progress.