PHYTOCHEMICALS+AND+A+HEALTHY+DIET

> 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] > 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] > 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. > [|Top] > 1 class period for research, filling in the table, and answering a few questions. > [|Top] > 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** > || 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 || || || > [|Top] > 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] > In this WebQuest, students do some Internet research on phytochemicals and a healthy diet. They learn what phytochemicals are, the types of foods that contain important phytochemicals, and what the health benefits are for each type of phytochemical. Students discover the importance of including several servings of fruits and vegetables in their daily diet. Finally, they compile the information gathered in a table, then answer several questions about phytochemicals and a healthy diet. > [|Top] > Students will complete a table that lists the phytochemicals found in foods or groups of foods as they explore the Internet sites given. Each web site has some of the information they will need to complete the table, but several of the foods listed are discussed on more than one web site. Students should be able to fill in the information requested for the ten foods listed in the table. From their Internet research, students should also be able to answer the questions given. > **Objectives** >> >> > [|Top] > Students will use the Internet links given to find out about phytochemicals and their health benefits. They will learn which foods contain which phytochemicals, and what phytochemicals have been proven to provide health benefits. They will find out if cooking destroys these health benefits, and if taking phytochemicals in pill form provides the same health benefits as eating the food directly. Finally, students with complete a table and answer a set of questions to demonstrate what they have learned regarding phytochemicals and a healthy diet. > [|Top] > 1 class period for research, filling in the table, and answering a few questions > [|Top] > As students progress through the list of web sites, you may help them to focus on what they need to know to fill in the table and answer the questions. Several of the web sites have links to other web sites with relevant information. If time allows, you may want to allow students to explore this subject further. Student tables may look different from the table given here; check on student work to make sure they have listed the correct phytochemicals and health benefits or diseases treated for each food or food group. > [|Top] > Evaluation of student work will depend upon the extent of the material listed in their tables. Students must have at least five active volcanoes listed in their tables and identified on their maps. However, students may have more than five listings; additional listings may add points to their total score as long as other criteria have been met. Make sure that the volcanoes listed can be found along the ring of fire where the Pacific Plate converges with other tectonic plates. Once students have completed the table, you may wish to use the rubric below for scoring their work. The rubric is based on five volcanoes in the table. > || Broccoli, cauliflower || indoles, isothiocyanates, sulfaforaphane, thiols || triggers enzyme systems to block or suppress cellular DNA damage; reduces size of cancer tumors; fights breast cancer || > || Garlic || ajoene, diallyl sulfide || enhances immune system; increases production of enzymes that help excrete carcinogens; decreases tumor size; reduces serum cholesterol levels || > || Onions || allylic sulfides || enhances immune system; increases production of enzymes that help excrete carcinogens; decreases tumor size; reduces serum cholesterol levels || > || Citrus fruits || monoterpenes, carotenoids, flavonoids || anti-inflammatory and antitumor activity; anticoagulants; protects eyes from macular degeneration || > || Tomatoes, peppers || lycopene || protects against heart disease, protects against some forms of cancer || > || Grapes, berries, cherries, apples, cantaloupes || ellagic acid, phenols, flavonoids || enhances immune system; protects against some forms of cancer || > || Soybeans, beans, oats, seeds, whole grains, brown rice || flavonoids, phytic acid, saponins || reduces cholesterol; protects against breast and ovarian cancer; antioxidants; starves tumors by restricting growth of new blood vessels to supply tumor; protects against heart disease || > || Licorice root, green tea || glycyrrhizm catechins || protects against cancer; protects against heart disease || > || Spinach || lutein, zeaxanthin || protects eyes against macular degeneration || > || Ginkgo biloba || terpene lactones || improves cognitive functioning; improves functioning of Alzheimer's disease patients ||
 * An Internet WebQuest**
 * PHYTOCHEMICALS AND A HEALTHY DIET**
 * Introduction**
 * Task**
 * Resources**
 * **[|Antioxidants and Other Phytochemicals: Current Scientific Perspective.]** Go to this site to read about the results of clinical trials that examined the benefits of antioxidant phytochemicals such as vitamins C and E and beta-carotene (which the body converts to vitamin A).
 * [|**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?]** This site from Oregon State contains images, links, references, and instructional materials on food and their resource. You'll find a list of many foods containing phytochemicals beneficial to health.
 * Time**
 * Process**
 * **Food** || **Phytochemical(s)** || **Health Benefit/Disease Treated** ||
 * //Questions about Phytochemicals and a Healthy Diet//**
 * 1) 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?
 * 2) Many vegetables are prepared by cooking, such as broccoli and cauliflower. Does cooking destroy the phytochemicals found in these foods?
 * 3) 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?
 * Conclusion**
 * WebQuest Teacher Page**
 * An Internet WebQuest**
 * PHYTOCHEMICALS AND A HEALTHY DIET**
 * Introduction**
 * Task**
 * **Define** the word phytochemical and explain the importance of phytochemicals in a healthy diet.
 * **Identify** the phytochemicals that are found in a variety of fruits and vegetables.
 * **Discuss** the health benefits of eating natural foods that contain phytochemicals.
 * Resources**
 * Time**
 * Process**
 * Evaluation**
 * **Food** || **Phytochemical(s)** || **Health Benefit/Disease Treated** ||

> Once students have completed the table and answered the questions, you may wish to use the rubric below for scoring. The rubric is based on ten foods or food groups listed in the table. > Rubric || Possible > Points* || Self-//** > **//Assessment//** || **//Teacher//** > **//Assessment//** || > || Each food or group has at least one phytochemical listed || 10 || || || > || Each food or group has at least one health benefit or disease treated listed || 10 || || || > || Information correct for each phytochemical listed || 10 || || || > || Information correct for each health benefit/disease treated listed || 10 || || || > || Answers to three questions correct || 10 || || || > || **Total Possible Points** || **50** || || || > *//Rate each category according to the following scale: Excellent – 9-10 points; Very Good – 7-8 points; Good – 5-6 points; Satisfactory – 3-4 points; Poor – 1-2 points; and Unsatisfactory – 0 points.// [|Top] > Students should be able to fill in the table and answer the questions given. Students should also be able to answer the question about what changes they should make in their diets to protect themselves from cardiovascular disease and cancer. Students should be able to support the data in their tables and their answers to questions with information gathered in their Internet research. > [|Top]
 * // Questions about Phytochemicals and a Healthy Diet //**
 * 1) cancer, diabetes, cardiovascular disease, hypertension
 * 2) According to scientific studies, cooking does not destroy the phytochemicals in foods. In fact, in some cases cooking enhances the effects of the phytochemicals.
 * 3) According to scientific studies, taking phytochemicals in pill form does NOT provide the same health benefits as eating the food itself. Perhaps this is because each food contains many phytochemicals and some of these may work together to provide the health benefit in ways not yet understood.
 * **//Table and Map
 * Conclusion**