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The amount of blue-enriched light needed to reduce melatonin levels in this study did not exceed safety standards for the eyes and did not cause immediate harm to eye tissue.
Exposure to artificial light at night reduces the body's production of melatonin, a hormone involved in sleep regulation, and the more light a person is exposed to, the more melatonin is suppressed,...
Light that contains more blue wavelengths can reduce melatonin production at lower brightness levels than light with less blue, meaning it has a stronger biological effect for the same amount of...
Higher levels of broad-spectrum light reaching the eye are linked to greater reductions in nighttime melatonin levels in healthy adults, with more light leading to more suppression.
Exposure to artificial light rich in blue wavelengths (400–500 nm) during nighttime is linked to a greater reduction in melatonin levels in the blood of healthy adults compared to light with less...
People who drink more fluids tend to excrete more iodine in their urine, even when their dietary iodine intake from foods like salt, milk, and fish is accounted for. This suggests that how much fluid...
When measuring iodine levels in urine to assess iodine status, the total amount of urine produced in 24 hours can affect the results, because more urine means more iodine is excreted, even if iodine...
Drinking large amounts of non-milk beverages like almond or oat milk may reduce iodine levels in the body because these drinks contain very little iodine, and increased urine output removes more...
In adolescent girls, each extra liter of urine produced is linked to a greater amount of iodine being removed from the body compared to adolescent boys, suggesting that kidneys process iodine...
When healthy adolescents and adult women drink more fluids and produce more urine, their bodies excrete more iodine through urine, even when their diet stays the same.
After intense exercise, two types of antimicrobial proteins in saliva rise together, while a third immune protein falls — indicating they are controlled by different biological mechanisms.
After intense exercise, the amount of immunoglobulin A secreted into saliva drops, which may temporarily reduce the mouth's ability to block pathogens from entering the body.
Intense exercise reduces saliva production and makes it more concentrated, which can make it look like antimicrobial proteins have increased even if their total amount hasn't changed.
After intense exercise, levels of the stress hormone cortisol rise in saliva, and this increase is linked to lower levels of two antimicrobial proteins, hinting that stress pathways may influence the...
One hour of intense exercise causes a short-term rise in two antimicrobial proteins in saliva while reducing another key immune protein, indicating that physical stress triggers complex, opposing...
Even after taking 600 mg of caffeine daily for five days, the body still shows a measurable increase in cortisol levels after a subsequent dose, indicating that the stress response to caffeine does...
After five days without caffeine, the body's cortisol response to a 250 mg dose of caffeine returns to its original strength, suggesting that tolerance to caffeine is temporary and linked to recent...
Even when people drink 300 mg of caffeine daily, their cortisol levels stay higher than normal for up to six hours after an afternoon dose, showing that the body's stress response system does not...
Taking 600 mg of caffeine per day for five days leads to a smaller increase in cortisol levels after a later caffeine dose compared to taking 300 mg per day, suggesting the body's stress hormone...
Taking 300 or 600 milligrams of caffeine daily for five days lowers the cortisol spike that occurs when you later take another 250 milligrams of caffeine, but cortisol levels still rise...
After 90 minutes of intense aerobic exercise, levels of the hormone DHEA remain stable in soccer players who train recreationally, while cortisol levels rise temporarily.
In recreationally trained soccer players, intense aerobic exercise causes a temporary rise in cortisol but does not change the natural daily decrease in cortisol and dehydroepiandrosterone levels...
In recreationally trained soccer players, 90 minutes of intense aerobic exercise leads to a temporary rise in cortisol levels in saliva at midday and late afternoon, depending on when the exercise...
When exposed to emotional stress, women show larger increases in heart rate and nervous system activation than men, even when differences in age, body weight, and stress hormone levels are taken into...