Heart 2: Changing Lifestyles and Heart Health

Photo Credit: Science NetLinks

Purpose

To examine and evaluate changes in diet and lifestyle from prehistoric to modern times and how these differences have spurred the development (and better treatment) of heart disease.

Context

This lesson is the second of a two-part series that explores different aspects of the human heart and the various changing conditions that have affected the health of billions of people from prehistoric to modern times.

This first lesson, Heart 1: Transplant, focuses on the state of medical care of the human heart today and on modern medical advances—such as heart transplants—that give today's human beings a better chance of staying healthy than their forebears had, as noted in the first part of the benchmark for this lesson. This second lesson, Heart 2: Changing Lifestyles and Health, examines the history of human diet and trends in care of the heart, comparing it with today's eating habits and lifestyles, many of which may not be good for human health.

Few students walk around in the hustle and bustle of modern life being fully aware of themselves as human organisms that are made up of a plethora of body parts and systems that require certain types and amounts of food and exercise to optimize and prolong their performance and life. However, by the end of elementary school, students should know that good health involves a healthy diet, regular exercise, and the avoidance or limitation of certain substances that negatively impact healthy body operation—like tobacco, alcohol, drugs, and pollution.

By high school, students should also be aware that physical health continues to be threatened by outside organisms like bacteria, fungi, viruses, and infectious disease, many of which are rejected by the body's own natural defenses, like the skin, various body secretions, and the immune system. However, certain types of viral diseases—like AIDS—can break down these natural barriers and leave a person rattled with life-threatening infections. In addition to infectious disease, students should also have an understanding that their health can be threatened by internal malfunctions in their body parts or systems. These may be caused by "deviant genes," which are either inherited or formed through mutation and which can leave the body more susceptible to developing certain diseases, like heart disease or depression. Changing physical environments, social settings, and living habits—as compared to habits during prehistoric times—can also negatively impact a person's physical health, though medical science continues to develop new techniques to identify, diagnose, treat, prevent, and monitor disease. (Science for All Americans, pp. 80–82, 143–146.) These and other related factors will be explored and emphasized in this two-part lesson series on the heart.

Research has shown a number of misconceptions students have about physical health that are worth addressing and alleviating in the course of these lessons. For example, studies indicate that a sizeable proportion of adults have little knowledge of internal organs or their location. Regarding the heart, researchers have discovered that upper elementary school students realize that the heart is a pump, but they are not aware that the blood returns to the heart. Also, researchers found that students of all ages hold wrong ideas about the structure and function of blood, the structure and function of the heart, the circulatory pattern, the circulatory/respiratory relationships, and the closed system of circulation (and that these misconceptions are difficult to change). And, while many students associate health primarily with food and fitness, it has been shown that middle-school and high-school students' wrong ideas about the causes of health and illness may derive from cultural knowledge. Further, students tend to believe that they have very little personal control over their health and life spans. They also are often unable to explain their knowledge about nutrition and fitness in scientific terms. (Benchmarks for Science Literacy ,pp. 344–346.)

Motivation

First, briefly review what students learned in Heart 1: Transplant. This can be done by covering the key points in each of their Web resource readings or by eliciting information from the class on what they know about the heart and modern ways of treating heart disease, which reflects and supports the first part of the benchmark.

Make sure that students have come away from Heart 1 with a better understanding of the basic facts, statistics, workings, and structure of the heart. Ask them to show a working knowledge of the causes of heart disease and the variety of modern ways it is treated. In particular, they should convey an understanding of heart disease in terms of heart transplantation, its history, operation techniques, related developments, and the various moral, medical, and ethical dilemmas that continue to surround its ongoing development.

Next, as an extension of their review of the heart, ask students to describe what they would consider to be a healthy diet. Let the open-ended questions below provide a basis for your discussion. Again, the purpose here is to warm students up by reviewing previous material and drawing out more of what they know about general health information (this should help them begin to focus on the second part of the central benchmark).

Ask students:

What, in your opinion, constitutes a healthy diet? Offer examples.
How does your own diet compare? Why?
What kinds of foods or habits do you think lead to heart disease?
What besides food contributes to a healthy diet and lifestyle?
Why do you think heart disease is the number one cause of death among Americans?
What kinds of things, if any, do you do to help prevent heart disease in your own life?

(Accept all answers and opinions. Encourage students to elaborate on their views.)

Now, go further by asking some questions that will get students thinking about how modern lifestyles are different from those for earliest humans, and even for humans in the more recent past.

Ask students:

Do you think heart disease has always been the primary cause of death for human beings? Why or why not?
Do you think heart disease was a problem for people hundreds or thousands of years ago? Why or why not?
How do you think their diet and lifestyles compare to ours today?
Do you think there is anything we can learn from them about improving our health (and avoiding heart disease)?

(Accept all answers and opinions. Encourage students to elaborate on their views.)

Development

Have students work their way through the three resources below. Inform them that they will be responsible for the material. Discuss the key points and interesting, applicable findings of each reading. For answers to the general discussion questions below, check the Teacher Answer Sheet as you progress.

Using the Changing Lifestyles and Heart Health student E-Sheet to guide them, have students read Heart History, a brief yet informative synopsis of the causes and potential cures of heart disease from a historical perspective. Encourage them to read through the "milestones of cardiology" link as well. Then hold an open discussion to gauge their reactions to what they have learned (and apply it to their own lives). Use the questions below as a basis; for answers, check the Teacher Answer Sheet .

Ask students:

Why was heart disease almost nonexistent prior to the 20th century? Explain.
How has medical science helped to address this key health problem?
Name an automated product that you use regularly. What would you do if you didn't have this? How might that affect your health?
What more do you think should be done about heart disease?

Using the student E-Sheet, have students read through The New Cholesterol. This resource covers the inner, blood-based risk factors of heart disease and their potential remedies. Since this reading is a more specific and technical medical exploration of the causes of heart disease than the first, continue the open discussion approach with students established earlier. You may guide the review and discussion using the questions below; for answers, check the Teacher Answer Sheet .

Ask students:

Why are researchers interested in investigating the unproven risk factors that may lead to heart disease?
What are some of these factors? What are they thought to do?
What do scientists believe to be the key in lowering homocysteine levels in the blood?
What is atherosclerosis?
How do today's doctors treat people at risk for heart disease?
Why are more studies needed?
What kinds of science and technology are currently being used to investigate, monitor, and prevent heart disease?

Next, the student E-Sheet will refer students to Paleolithic Nutrition: Your Future Is In Your Dietary Past. As students read this extremely valuable and highly informative article, have them jot down any differences they find between modern diets and lifestyles and those of the Paleolithic era. An area of particular importance is at the end of the reading that deals with the question, "Where do we and our diets go from here?" Use the general questions below to guide your discussion of the material and to gauge students' reactions to this virtually life-saving information. Question answers can be found on your Teacher Answer Sheet. Other more difficult and technical questions may be posed based on your teaching goals and the level of your students.

Ask students:

What are some of the differences between the way human beings ate and lived in the Paleolithic era as compared to today?
What were the main causes for this change in diet and lifestyle?
What is the problem with modern diets in terms of genetics?
What is considered to be the Paleolithic diet?
How does the modern diet compare? How does yours compare?
Does reading these findings make you want to change your own diet? Do you think these changes can last long-term? Why or why not?

Divide the class into two halves: on one side, hunter-gatherers, on the other, modern students. Have each side defend, debate, and criticize the diets and lifestyles of the other.

In general, students should walk away from this reading with a much clearer and more specific idea of the problems with modern diets and lifestyles, how their own health is naturally at risk, and that modernity does not always mean progress.

Have students individually list the top five worst foods they eat on a regular basis and the top five healthy foods they would like to incorporate into their regular diets (but never have). Have them read their lists aloud to the class. Discuss related issues.

Assessment

Students should understand that differing conditions or lifestyle changes have had both positive and negative impacts on human health. Use the Student Quiz to assess student understanding of these concepts. You can also use theTeacher Answer Sheet covering the three readings in this lesson to assess student understanding of the specific concepts covered in this lesson.

To reinforce the ideas in a different context, you can ask students to discuss or write about other changes that have had a mixed impact on our health. For example, students can discuss and research health risks associated with environmental changes due to technology.

Extensions

The History of the Heart: The Popular Heart provides an interesting look at the history and cultural impact of the heart. This resource is a chronicle of the heart and its powerful symbolism in literature, poetry, television, movies, and music. Students may add to the growing lists and even write a heart-based poem.

Infectious History is an essay exploring the global history of the "harrowing cohabitation of humanity and microbes." Though wonder drugs of the 1950s helped to alleviate the threat of microbes, the spread of new and more infectious agents like HIV and Ebola has created a whole new worldwide crisis. (Registration is required.)

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