Tip #18: Ensure you’re getting enough Selenium
Ensure you’re getting enough Selenium
•Selenium is used for preventing various cancers including cancer of the prostate, stomach, lung, and skin.
•Higher toenail selenium levels were associated with a reduced risk for advanced prostate cancer.
•Studies suggest that people who consume lower amounts of selenium could have an increased risk of developing cancers.
•Studies support a role for selenium supplementation in both preventing and slowing the progression of prostate cancer.
•Extremely high intakes of selenium can cause severe problems, including difficulty breathing, tremors, kidney failure, heart attacks, and heart failure.
Selenium is a mineral. It is taken into the body in water and foods. People use it for medicine.
Most of the selenium in the body comes from the diet. The amount of selenium in food depends on where it is grown or raised. Crab, liver, fish, poultry, and wheat are generally good selenium sources. The amount of selenium in soils varies a lot around the world, which means that the foods grown in these soils also have differing selenium levels. In the U.S., the Eastern Coastal Plain and the Pacific Northwest have the lowest selenium levels. People in these regions naturally take in about 60 to 90 mcg of selenium per day from their diet. Although this amount of selenium is adequate, it is below the average daily intake in the U.S., which is 125 mcg.
Selenium is used for diseases of the heart and blood vessels, including stroke and “hardening of the arteries” (atherosclerosis). It is also used for preventing various cancers including cancer of the prostate, stomach, lung, and skin.
Cohort Study Indicates That Selenium May Be Protective Against Advanced Prostate Cancer
- Higher toenail selenium levels were associated with a reduced risk for advanced prostate cancer.
- Toenail selenium levels reflect long-term selenium intake.
- Further studies in low-selenium populations are required.
A greater level of toenail selenium was associated with a significant decrease in the risk for advanced prostate cancer, according to data presented at the AACR Annual Meeting 2013, held in Washington, D.C., April 6-10.
“This could mean, based on our data and based on data from other studies, that selenium is a modifiable risk factor of advanced, clinically relevant prostate cancer,” said Milan S. Geybels, M.Sc., a doctoral candidate in cancer epidemiology at Maastricht University, in Maastricht, the Netherlands.
The Netherlands Cohort Study on diet and cancer is a prospective cohort study that includes 58,279 men who were aged 55 to 69 years at entry in September 1986. Geybels and colleagues analyzed data from 898 men who were diagnosed with advanced prostate cancer during 17.3 years of follow-up of the cohort.
According to Geybels, previous studies investigating the association between selenium levels and prostate cancer have yielded varying results. One large clinical trial showed that selenium supplementation had no protective effect, while several prospective, observational studies indicated that higher levels of selenium were associated with a reduced prostate cancer risk, especially for advanced prostate cancer.
“Our study is interesting because we specifically investigated men with advanced prostate cancer, a type of prostate cancer associated with a poorer prognosis,” Geybels said. “Also, while most of the prior research, including the large clinical trial, involved men with moderate-to-high selenium levels, men in The Netherlands Cohort Study have selenium levels that range from low to moderate. This is important because low selenium is expected to be related to a higher disease risk.”
He and his colleagues chose toenail selenium as the study biomarker because it reflects long-term exposure, as opposed to blood, which is best for monitoring recent selenium exposures.
The data revealed that greater levels of toenail selenium were associated with a substantially reduced risk for advanced prostate cancer. Men with the highest toenail selenium levels had a more than 60 percent lower risk for advanced prostate cancer compared with men with the lowest toenail selenium levels.
“Our findings need to be replicated in further prospective studies, with an extended follow-up for the assessment of incident advanced prostate cancer, and with a wide range of toenail selenium that includes low selenium levels,” Geybels said. “If our results can be confirmed, a prevention trial of selenium and prostate cancer in a low-selenium population may be justified.”
Selenium and cancer
What is selenium and what does it do?
Selenium is a nutrient that the body needs to stay healthy. Selenium is important for reproduction, thyroid gland function, DNA production, and protecting the body from damage caused by free radicals and from infection.
What happens if I don’t get enough selenium?
Selenium deficiency is very rare in the United States and Canada. Selenium deficiency can cause Keshan disease (a type of heart disease) and male infertility. It might also cause Kashin-Beck disease, a type of arthritis that produces pain, swelling, and loss of motion in your joints.
What are some effects of selenium on health?
Scientists are studying selenium to understand how it affects health. Here are some examples of what this research has shown.
Studies suggest that people who consume lower amounts of selenium could have an increased risk of developing cancers of the colon and rectum, prostate, lung, bladder, skin, esophagus, and stomach. But whether selenium supplements reduce cancer risk is not clear. More research is needed to understand the effects of selenium from food and dietary supplements on cancer risk.
Can selenium be harmful?
Yes, if you get too much. Brazil nuts, for example, contain very high amounts of selenium (68–91 mcg per nut) and can cause you to go over the safe upper limit if you eat too many. Extremely high intakes of selenium can cause severe problems, including difficulty breathing, tremors, kidney failure, heart attacks, and heart failure.
Are there any interactions with selenium that I should know about?
Yes, some of the medications you take may interact with selenium. For example, cisplatin, a chemotherapy drug used to treat cancer, can lower selenium levels, but the effect this has on the body is not clear.
Tell your doctor, pharmacist, and other health care providers about any dietary supplements and prescription or over-the-counter medicines you take. They can tell you if the dietary supplements might interact with your medicines or if the medicines might interfere with how your body absorbs, uses, or breaks down nutrients.
Selenium Prevents and Slows Prostate Cancer
Source: Life Extension
…In addition to its clear role in preventing prostate cancer, selenium may slow the progression of already established prostate cancer. In a six-week trial, 37 men with prostate cancer and increasing PSA levels were given either a placebo or an antioxidant supplement containing selenium, plant estrogens, and other antioxidants. In the supplemented group, male hormone levels (known to stimulate prostate cancer growth) were lower during treatment. In addition, free PSA levels rose during treatment with the placebo, but decreased during antioxidant supplementation.
These studies, along with recent findings that selenium is selectively concentrated in prostate tissue, strongly support a role for selenium supplementation in both preventing and slowing the progression of prostate cancer.
Published Clinical Trials / Studies / Reviews
Selenium in cancer prevention: a review of the evidence and mechanism of action
Page updated 2023