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Brazil nuts: an effective way to improve selenium status
Christine D Thomson1, Alexandra Chisholm, Sarah K McLachlan
1Department of Human Nutrition, University of Otago, Dunedin, New Zealand. christine.thomson@otago.ac.nz
The American Journal of Clinical Nutrition
|February 9, 2008
Summary
Eating two Brazil nuts daily effectively boosts selenium levels and glutathione peroxidase (GPx) activity, comparable to selenomethionine supplements. This natural food source can improve selenium status without needing fortification.
Area of Science:
- Nutritional Science
- Human Physiology
- Biochemistry
Background:
- Brazil nuts are a natural, rich source of selenium.
- Human bioavailability of selenium from Brazil nuts has not been previously studied.
Purpose of the Study:
- To investigate the efficacy of Brazil nuts in enhancing selenium status.
- To compare the bioavailability of selenium from Brazil nuts against selenomethionine.
Main Methods:
- A 12-week randomized controlled trial involving 59 adults.
- Participants consumed daily: 2 Brazil nuts (approx. 53 mug Se/day), 100 mug Se as selenomethionine, or placebo.
- Measured plasma selenium and glutathione peroxidase (GPx) activity at baseline and various intervals.
Main Results:
- Both Brazil nuts and selenomethionine significantly increased plasma selenium and GPx activity compared to placebo.
- The increase in whole blood GPx activity was significantly greater in the Brazil nut group than in both placebo and selenomethionine groups.
- No significant difference was observed between Brazil nut and selenomethionine groups for plasma selenium and plasma GPx changes.
Conclusions:
- Daily consumption of two Brazil nuts is as effective as 100 mug of selenomethionine for improving selenium status and GPx activity.
- Incorporating Brazil nuts into the diet offers a natural strategy to enhance selenium status in populations like New Zealanders.
- This dietary approach may reduce reliance on selenium fortification or supplements.
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