|
|
|
PHYTOCHEMICALS AND A HEALTHY
DIET
Introduction
Do you like broccoli and cauliflower? Do you eat carrots
and peas? Perhaps you drink orange or grapefruit juice for
breakfast every day, or eat an apple at lunchtime. Fruits
and vegetables such as these are essential to a healthy
diet, yet many people do not eat enough of these natural
foods. There is mounting evidence that eating a well-rounded
diet, consisting of several servings of fruits and
vegetables every day, can reduce the effects of aging, and
help to prevent diseases such as cancer, diabetes, and heart
disease. The chemicals that occur naturally in plants, such
as fruits and vegetables, are called phytochemicals.
You may have seen television commercials that discuss
the health benefits of taking supplements that contain
lutein and capsaicin, two types of phytochemicals. What are
phytochemicals exactly? What foods contain important
phytochemicals? Do you have to eat broccoli to obtain its
healthful phytochemicals, or can you benefit equally by
taking a pill that contains those phytochemicals? In this
WebQuest, you'll learn the answers to these questions as you
explore the nature of phytochemicals.
Top
Task
Your job in this WebQuest is to learn all about the
phytochemicals found in fruits and vegetables, and the
benefits of eating these foods as part of a balanced diet.
You will discover what phytochemicals have been studied
scientifically, and what these research studies have
discovered. You will learn about the different
phytochemicals that can be found in natural foods, and the
health benefits of each type. You will fill in a table in
which ten different foods or groups of foods are listed. For
each food or group of food, you will list the important
phytochemical(s) each contains, and the health benefits of
eating that food. Finally, you will answer a few questions
about phytochemicals to demonstrate what you have learned in
your Internet research.
Top
Resources
Look at the web sites given here to find the information
that will enable you to complete your table on
phytochemicals and answer a few questions.
- Position:
Phytochemicals and functional foods. Visit this
site by the American Dietetic Association to read an
excellent paper about the benefits of phytochemicals in
the diet. The article discusses some of the phytochemicals
in foods such as broccoli, onions, garlic, and soybeans
that have been shown in scientific studies to have an
impact on cancer, diabetes, cardiovascular disease, and
hypertension.
- Phytochemicals
- Vitamins of the Future? Visit this Ohio State
University site to learn more about the use of
phytochemicals to combat many types of cancer. The
American Cancer Society suggests that people eat mostly
plant foods to combat cancer rather than animal-based
foods. At this site you can see a list of foods and the
phytochemicals they contain.
- Phytochemicals
and Cardiovascular Disease. Go to this site by the
American Heart Association to find out what phytochemicals
are being used to treat heart disease. The Association
recommends that people eat more fruits and vegetables to
obtain the optimum benefits from a healthy diet.
- The
Phytochemical Collection. Visit this site by
Florida State University for a brief history of the
importance of including fruits and vegetables in the diet.
Scroll down to see a listing of phytochemicals that have
been shown scientifically to combat diseases.
- What
are the benefits of Vitamins and Phytochemicals?
Go to this site to read about the general health
benefits that are associated with vitamins and
phytochemicals. Scroll down to phytochemicals to find out
the difference between garlic supplements and natural
garlic.
- Phytochemicals:
Guardians of Our Health. At this site you
can read about the anticancer potential of foods such as
garlic, soybeans, cabbage, ginger, licorice, and carrots.
Scroll down to read about the health benefits of soy,
citrus fruits, and whole grains.
Top
Time
1 class period for research, filling in the table, and
answering a few questions.
Top
Process
Now that you have completed your research on
phytochemicals, prepare a table like the one below with the
information that you have gathered about the foods listed.
For each food or group of foods, list the phytochemicals
they contain, then list the health benefits of the
phytochemicals or the diseases that those phytochemicals can
be used to treat. You will need to look at all of the web
sites listed in order to complete the table. Once the table
has been filled in, answer the questions that follow.
Table 1. Phytochemicals and a Healthy Diet
| Food |
Phytochemical(s)
|
Health
Benefit/Disease Treated |
| Broccoli, cauliflower
|
|
|
|
Garlic |
|
|
| Onions |
|
|
| Citrus fruits |
|
|
| Tomatoes, peppers |
|
|
| Grapes, berries,
cherries, apples, cantaloupes |
|
|
| Soybeans, beans, oats,
seeds, whole grains, brown rice |
|
|
| Licorice root, green
tea |
|
|
|
Spinach |
|
|
Questions about Phytochemicals and a Healthy
Diet
- Scientific studies have shown that phytochemicals are
associated with prevention and treatment of four leading
causes of death in the United States. What are they?
- Many vegetables are prepared by cooking, such as
broccoli and cauliflower. Does cooking destroy the
phytochemicals found in these foods?
- Health food stores already sell some phytochemicals in
pill form. Does taking phytochemicals in a pill form
provide the same health benefits as eating the food
itself?
Top
Conclusion
In the process of completing this WebQuest, you've become
informed about the importance of including fruits and
vegetables in your diet. You have learned what
phytochemicals are and what foods contain important
phytochemicals. You have developed critical thinking skills
as you explored the health benefits of phytochemicals. To
protect yourself from developing diseases such as cancer and
cardiovascular disease in the future, what changes should
you make in your diet today?
Top
| |
|
