Notes to broadcasters
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Over the past fifteen years, a growing body of scientific literature suggests that adequate consumption of selenium in the diet strongly improves immune response. For people living with HIV and AIDS (PLWHA), selenium can improve or even eliminate the signs and symptoms of AIDS.
Fifty to 200 milligrams of selenium per day is safe for a healthy person. Someone with a compromised immune system, such as a PLWHA, may require double this amount to improve selenium levels in the blood. Selenium can be acquired through food and/or through nutritional supplements. For selenium to work effectively in preventing and fighting against HIV/AIDS and other viral diseases, three additional nutrients must be consumed: cysteine, glutamine and tryptophan. Where soil quality is good and produce is fresh, these four essential nutrients are found in the following foods:
- Selenium: Brazil nuts (19 micrograms (millionth of a gram) of selenium per gram of Brazil nuts), tuna (74 micrograms per 100 grams), beef (35 micrograms per 100 grams), cod (37 micrograms per 100 grams), brewer’s yeast, wheat germ, whole wheat, kelp (seaweed), shellfish, barley, organ meats such as liver and kidney. If grown in selenium-rich soil: broccoli, garlic, mushrooms.
- Cysteine: Duck, turkey, pork, wheat germ, yoghurt.
- Glutamine: Wheat germ, raw spinach, and high protein foods such as beef, chicken, fish, beans, soy products, dairy products.
- Tryptophan: Chicken, red meat, eggs, almonds, salted anchovies, dairy products, soy beans and soy products, tuna, shellfish.
Though Brazil nuts are the highest-known dietary source of selenium, they are not likely available in many parts of Africa. Tuna is also a very good source of selenium, but may also not be available in your region. Thus, there are three separate versions of a paragraph in which the nutritionists talk about good sources of selenium. These paragraphs are labelled (1), (2) and (3). Please use the paragraph which is most appropriate for your listening audience.
Script
CHARACTERS:
There are three characters in this radio program: one radio host, one nutritionist and one agricultural extension officer. Please use names that are familiar to your audience, and ensure that one of the guests is a woman and the other is a man. Introductory music up for ten seconds, then fade out.
HOST:
Hello and welcome to the program. Today I have two special guests with me to discuss a new development in HIV and AIDS research. We will talk about how consuming a mineral called selenium can be very useful to women, men and children living with HIV and AIDS.
My first guest is[name of agricultural extension officer], who is an agricultural extension officer.
AGRICULTURAL EXTENSION OFFICER:
Hello.
HOST:
My second guest is[name of nutritionist], who is a nutritionist.
NUTRITIONIST:
Good morning(afternoon, evening).
HOST:
Let’s begin with[name of nutritionist]. Will you describe selenium and why our bodies need it?
NUTRITIONIST:
Selenium is a micronutrient found in certain foods. We call it a “micronutrient” because it is present in foods in very small quantities. Our bodies need these small amounts of selenium to keep our immune systems working properly. Our immune systems fight disease and keep us healthy.
HOST:
How much selenium does a person need each day?
NUTRITIONIST:
Women and men require different amounts of selenium: adult women without HIV or AIDS need about 60 micrograms of selenium a day, and adult men without HIV or AIDS need about 75 micrograms of selenium a day. Adults with HIV or AIDS may need twice the amount of selenium. But it’s important not to eat too much selenium, because too much can be poisonous.
AGRICULTURAL EXTENSION OFFICER:
Selenium is also important to the health of farm animals and livestock. But, like humans, if animals eat too much selenium, they can become sick.
HOST:
So it’s important to eat the right amount of selenium to stay healthy. And it’s important to remember that the amount of selenium we need changes with our HIV status.[Name of nutritionist], will you please tell our listeners which kinds of foods contain selenium?
NUTRITIONIST:
The best food for selenium is Brazil nuts, but selenium is also found in seafood, whole wheat, brewer’s yeast and organ meats such as liver and kidney. Other foods like broccoli, garlic and mushrooms may contain selenium if they are grown in selenium-rich soils.
(1)
An adult without HIV or AIDS can meet his or her selenium needs by eating one or two Brazil nuts per day. Each nut contains between 65 to 200 micrograms of selenium. A microgram is one millionth of a gram. A person with HIV or AIDS may need twice that amount, or up to four Brazil nuts per day.
BROADCASTER:
If Brazil nuts are not available or eaten locally, you may substitute the nutritionist’s comment with one of the following paragraphs:
(2)
An adult without HIV or AIDS can meet his or her selenium needs be eating about one hundred grams of tuna per day. One hundred grams of tuna contain 75 micrograms of selenium. A microgram is one millionth of a gram. A person with HIV or AIDS may need twice that amount. Instead of twice the amount of tuna, the person can also eat a serving of whole wheat bread or whole wheat pasta or egg noodles with broccoli.
OR
(3)
Two hundred grams of beef is enough to meet the daily selenium needs of an adult without HIV or AIDS. Two hundred grams of beef contain 70 micrograms of selenium. A microgram is one millionth of a gram. A person with HIV or AIDS may need twice that amount. Instead of twice the amount of beef, the person can also eat a serving of whole wheat bread or whole wheat pasta or egg noodles with broccoli.
HOST:
Why do men, women and children with HIV and AIDS need more selenium than people without the disease?
NUTRITIONIST:
HIV and AIDS remove selenium and three other nutrients from the body as the disease develops. These nutrients are no longer available to the body, so the person’s immune system cannot work properly. When this happens, the person is nutrient-deficient and begins to show symptoms of HIV and AIDS.
HOST:
Before we move on, I need to ask you one question. We know selenium is one of the four nutrients. What are the other three?
NUTRITIONIST:
The other three are amino acids or proteins. They are tryptophan, cysteine and glutamine. These amino acids work together with selenium to ensure that the immune system is healthy. All four are needed. It is like growing crops: a farmer needs seeds, soil, water and sun for the crops to grow. If one element is missing, the crops will not grow properly. It is the same thing with selenium and HIV and AIDS. When the disease removes the nutrients from the body, a person must eat all four nutrients to minimize the effects of the disease.
HOST:
We know some dietary sources of selenium. What are some sources of these important amino acids?
NUTRITIONIST:
Good question. Tryptophan is found in chicken, red meat, eggs, dairy products, soy beans and tuna. Foods such as turkey, pork, wheat germ and yoghurt contain cysteine. Lastly, glutamine is found in wheat germ, raw spinach, beef, chicken, fish, beans, soy products and dairy products.
HOST:
So one food can have many nutrients. Tuna and beef each have selenium, tryptophan and glutamine. Three nutrients in one food item – very good. Listeners, we’re going to take a short break. We’ll be back soon with more information about selenium and HIV and AIDS.
Music break
HOST:
Hello listeners and welcome back to our program. I’m speaking with[name of nutritionist]and[name of extension officer]about selenium and HIV and AIDS. Earlier, we learned that selenium is important in reducing the symptoms of HIV and AIDS and can slow the progression of the disease. Now our listeners will probably want to know how selenium gets into our food.[Name of extension officer], how does selenium get into our food?
AGRICULTURAL EXTENSION OFFICER:
Selenium is a mineral that occurs naturally in the soil. When crops grow, they take up minerals from the soil, including selenium. But not all soils have equal amounts of selenium available for plants. There is usually more selenium in wetter areas than in arid or semi-arid areas. The amount of selenium in the soil is different in different countries and even within a single country. For example, Senegal has selenium-rich soils but Rwanda, Burundi and parts of the Democratic Republic of the Congo have selenium-poor soils.
HOST:
[Name of agricultural extension officer], can selenium be depleted from the soil?
AGRICULTURAL EXTENSION OFFICER:
Yes. Selenium levels in soils are decreasing because of acid rain. Acid rain is caused by human activities such as burning coal and gas that release pollutants into the atmosphere. These pollutants then become part of the rain, snow and fog. This precipitation is acidic and depletes soil selenium levels.
HOST:
Is there anything that farmers can do about this loss of selenium?
AGRICULTURAL EXTENSION OFFICER:
Yes, farmers can add fertilizers enriched with selenium to their fields. You can ask your extension officer about selenium-enriched fertilizers. Make sure to follow his or her instructions carefully so that you apply the right amount in the right way.
HOST:
If a farmer cannot get selenium-enriched fertilizers and the soils are poor in selenium, are there other ways that persons living with HIV or AIDS can get selenium?
NUTRITIONIST:
Yes. There are some nutritional supplements with selenium, tryptophan, cysteine and glutamine. You can talk with a pharmacist.
HOST:
I would like to thank our wonderful guests,[name of agricultural extension officer]and[name of nutritionist]for joining me on today’s program. We have learned how eating enough selenium and three important amino acids can improve the health of people with HIV and AIDS, and we have learned that growing crops in selenium-rich soils adds selenium to food crops. By eating the right foods, we can fight the disease.
Fade out music
Acknowledgements
Contributed by: Chris Gibb
Reviewed by: Edward Berkelaar, PhD, Associate Professor in the Department of Chemistry and Environmental Science, Redeemer University College, Ancaster, Ontario, Canada; Harold D. Foster, PhD, Professor in the Department of Geography, University of Victoria, Victoria, British Columbia, Canada; Peter van Straaten, PhD, Associate Professor of Agrogeology and Environmental Geology in the Department of Land Resource Science, University of Guelph, Guelph, Ontario, Canada.
Information sources
- Harold D. Foster. 2002. What really causes AIDS. Victoria, BC, Canada: Trafford Publishing.
- Office of Dietary Supplements, NIH Clinical Center and National Institute of Health. 2004.
- Dietary Fact Sheet: Selenium.
- Peter van Straaten. “Selenium” in Rocks for Crops: Agrominerals of sub-Saharan Africa. (unpublished chapter obtained from the author). Chapters on other agrominerals available online.