Selenium Clinical Evidence
Nutrition and Cancer
Topic:
Does 400 mcg of selenium supplementation daily decrease total cancer incidence?
Background:
Population studies indicate that people with higher selenium status are at decreased risk of cancer. The Nutritional Prevention of Cancer (NPC) study found that 200 mcg of selenium per day decreased total cancer incidence by a statistically significant 25%. What happens when the daily selenium dosage is increased to 400 mcg daily?
Study Type:
Human clinical intervention trial
Study Design:
Placebo-controlled: Patients were assigned to take either a daily selenium supplement or placebo.
Subjects:
424 patients
Dosage:
400 mcg of selenium per day or placebo
Results:
The researchers found that 400 mcg per day of selenium had no effect on total cancer incidence.
Conclusion:
Lower dosages of selenium may be preferred for cancer prevention.
Clinical Cancer Research
Topic:
Does selenium selectively accumulate in prostate tissue?
Background:
Population studies and clinical data suggest selenium could prevent prostate cancer, but it has not been shown that supplemental selenium leads to an increased concentration of selenium in prostate tissue versus other tissues. Does it?
Study Type:
Human clinical observation trial
Study Design:
Randomized, controlled: Half of the subjects were assigned to take selenium supplements, while the other half were simply observed.
Subjects:
66 men with prostate cancer
Dosage:
[? mg] selenium (as l-selenomethionine) per day
Results:
Among men taking supplements, the selenium concentration in prostate tissue increased 22% versus those in the observation group, and was higher than in adjacent tissue.
Conclusion:
These findings support the hypothesis that oral selenium supplementation may contribute to the cancer preventive effects of selenium.