U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Western Human Nutrition Research Center: Davis, CA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    Laboratories
                        Allen Group
                                    Bennett Group
                                    Stephensen Group
                                    Human Studies
                                    Metabolic Kitchen
                                    Huang Group
                                    Kable Group
                                    Keim Group
                                    Laugero Group
                                    Newman Group
                                    Lemay Group
                                    Support Staff
                    About Us
                        HistorySearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Pacific West Area Davis, California Western Human Nutrition Research Center Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications
- Charles Stephensen
- Charles Stephensen
- Brian Bennett
- Ellen Bonnel
- Yuriko Adkins
- Lindsay Allen
- Bess Caswell
- Liping Huang
- Mary Kable
- Nancy Keim
- Kevin Laugero
- Danielle Lemay
- John Newman
- Ryan Snodgrass
- Zeynep Alkan
- Allyson Deimeke
- Rashel (Shelly) DeCant
- Nicholas Esparza
- Steven Nguyen
- Erik Gertz
- Daniela Hampel
- Shurong Huang
- Xiaowen Jiang
- James Gomez
- Setti Shahab-Ferdows
- Debra Standridge
- Dave Storms

Title:   Author  item
                                            Hawkes, Wayneitem
                                            Keim, Nancy
  Submitted to: Journal of Nutrition
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 8/21/2003
                                    Publication  Date: 11/6/2003
                                    Citation: Hawkes, W.C., Keim, N.L. 2003. Dietary selenium intake modulates thyroid hormone and energy metabolism in men. Journal of Nutrition. 133:3443-3448, 2003.Interpretive Summary: Selenium is a mineral that has been officially recognized as essential to human health only since the 1980's.  Selenium can also be toxic when consumed at only 14 times the recommended intake.  Recent research suggests that selenium supplementation to about 5 times the RDA can reduce the risk of lung, colon and prostate cancers by 50% or more.  No studies have been done to assess the possible adverse effects of these high selenium intakes in healthy humans.  We confined 11 healthy men for 120 days to strictly control their eating and activities while we changed the amount of naturally occurring selenium they ate without changing anything else about their diets.  We found that high selenium (about 5 timesthe RDA) decreased the amount of active thyroid hormone in their blood and led to a steady slow weight gain.  On the other hand, we observed that low selenium increased their active thyroid hormone levels and led to a steady, slow weight loss.  These responses were opposite to what's been found in animals, showing the need to do such studies in humans.  The weight increases caused by high selenium could be an undesired side effect of taking selenium supplements to prevent cancer.
                                Technical Abstract: Eleven healthy men were fed a controlled diet of foods naturally high or low in selenium for 120 days.  Selenium intake was 47 :g/d for 21 days, then either 13 or 297 :g/d for 99 days, leading to significantly different blood selemium and glutathione peroxidase concentrations.  3, 3N, 5-Triodothyronine (T3) decreased in the high seleium group, increased in the low selenium group, and was significantly different between groups from day 45 onward.  The changes in T3 induced by dietary selenium were opposite to those previously observed in rats, but were consistent with the other metabolic changes in this study.  By day 64 the high selenium group started to gain weight, while the low selenium group began to lose weight, and the changes were significantly different between groups from day 92 onward.  Decrease in serum T3 followed by compensatory increases in serum thyrotropin suggested that a relatively hypothyroid state was induced by the high selenium diet, while increases of serum T3 and serum triglycerides followed by losses of body fat suggested that a relatively hyperthyroid state was induced by the low selenium diet.  More research is needed to assess the health implications and clinical significance of these apparent effects of dietary selenium.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov