Home > Encyclopedia of Food & Culture > Medicine

MEDICINE. Food plays both a causative and curative role in health and disease. Thus, its role in medicine may be as a risk factor for, protector against, or treatment of an illness. While too much food or exposure to certain foods can reduce someone's health, too little food or inadequate amounts of certain foods can be equally damaging. In the years before modern transportation, packaging, and refrigeration, medicine was primarily concerned with food deficiencies and food spoilage. The focus of medicine was on the identification of critical components of food and common pathogens and on the prevention of nutritional deficiencies and foodborne infections. The role of food in medicine has changed as food production, preservation, and preparation techniques have progressed. Today far more people in developed countries such as the United States suffer from excessive food consumption than from food deficiencies. In addition, certain components of food have been found to have therapeutic or protective properties when administered in levels greater than generally considered necessary. For instance, large quantities of vitamin A are used to treat acne, therapeutic quantities of vitamin E may be protective against heart disease, and extra fiber appears to reduce the risk of colon cancer. However, the problems of malnutrition or inadequate food intake and foodborne illness have not been eliminated. Undernutrition continues to plague developing nations, while the prevention and treatment of foodborne illness is a concern for all nations.

The Basics of Food and Health

Food is fundamental to support life. People get energy, water, and all of the building blocks for growth and proper bodily functioning from the foods they eat and the liquids they drink. The components of food necessary to life are termed "nutrients" and the study of the role of food in health is called nutrition. The goal of medicine is to ensure health, and because adequate nutrition is necessary to accomplish this, nutrition is a crucial component of medicine. Nutritional science combines food science and medical science. Nutrients include protein, fat, carbohydrates, fiber, thirteen vitamins, seventeen minerals, and more substances that are still being identified. The majority of nutrients essential to health are found in a variety of different foods. No one food is absolutely essential to support life. People with access to adequate amounts of food get all of the nutrients they need by eating a varied diet complete with fruits, vegetables, meat or meat alternatives, dairy foods, and grains. However, some people are not able to or do not choose to eat the full variety of foods available. These people may require special foods or supplements to meet their nutritional needs.

The Study of Food in Medicine

All branches of medicine, from pediatrics to geriatrics and from internal medicine to surgery, study food and its role in health and disease. Nutritional scientists in government, industry, and academia are constantly seeking to understand the role food plays in illness and well-being. Meanwhile health-care practitioners treat patients with nutritional plans and food supplements. Registered dietitians are health-care specialists who integrate food into medical treatment—this is referred to as medical nutrition therapy.

The Role of Food in Maintaining Health

Although the presence of adequate nutrition does not ensure health, it is a significant contributor. The energy contributed by the protein, carbohydrates, and fat in food provides the fuel for every element of body functioning from breathing to thinking to fighting disease to running marathons. Adequate energy intake is crucial to promote proper growth and development as well as to maintain healthy functioning once one is fully grown. Food also provides the materials necessary to build healthy bone, muscle, skin, hair, etc. For example, bone is a complex matrix of calcium, phosphorus, and collagen fibers. A person's bone strength is directly related to their nutrient intake such that inadequate calcium intake is one of the primary reasons for bone disease such as osteoporosis. Nutrients are also necessary to support proper chemical and neurological functioning. For example, fat insulates nerve fibers such that they can conduct electrical signals along the length of the body. Meanwhile, those electrical signals are generated via channeling ions such as sodium, potassium, and calcium into and out of the nerve cells. Finally, the neurotransmitters released from the nerve cells are made from amino acids contributed largely from proteins in the diet. Thus, thinking and feeling are intricately connected to food.

Food for Those Who Can't Feed Themselves

Food is generally eaten, or drunk, and swallowed. However, many people cannot obtain adequate nutritional levels by conventional ways of ingesting food. In the past, these people would suffer and die from malnutrition. Modern nutritional medicine offers people several alternatives to conventional chewing and swallowing of food so that those who cannot do so will not die. Liquid solutions have been manufactured by pharmaceutical companies that are easier to digest than solid food and provide 100 percent of nutritional needs. People who can drink but not eat rely on these formulas just as babies who cannot breast feed rely on baby formula to meet their nutritional needs. People who cannot consume anything orally are fed via a tube inserted into the stomach or intestines. Finally, those whose gastrointestinal tracts cannot absorb even liquids are fed intravenously with solutions that provide 100 percent of human nutritional needs.

Examples of Food as a Cause of Disease

Food allergies and intolerances are common medical reasons for eliminating specific foods from one's diet. An allergy is an immune response to proteins in food that the body identifies as foreign. The most common food allergies include those to peanuts, tree nuts, shellfish, milk, soy, corn, wheat, and eggs. Most allergies appear in childhood and require complete elimination of the offending food if the symptoms are to be eradicated. Childhood food allergies may persist for a lifetime or may resolve a few years after getting rid of the offending food. Symptoms of allergies may include rashes and other skin irritations, gastrointestinal inflammation and bleeding, and respiratory distress, which may even involve arrest of breathing.

Food intolerances are not allergies but rather uncomfortable reactions to food that are not generally considered life threatening. One well-known example is lactose intolerance. Lactose is the carbohydrate in milk and other dairy products. The body requires a specific enzyme if lactose is to be absorbed. As people age their bodies may make less of the enzyme necessary to break down lactose and as a result they may experience gastrointestinal distress, including such symptoms as gas or diarrhea, when they consume milk products containing lactose. Most people with lactose intolerance can tolerate dairy products if they accompany their meal with a lactase enzyme pill or if they consume dairy products pretreated with lactase enzyme. Thus, food technology allows people with intolerances to tolerate the offending foods but avoidance is the only option for people with food allergies.

In countries such as the United States where food is abundant, some of the greatest medical risks result from overeating rather than insufficient eating. For example, an excess intake of energy in the form of food leads to an increased risk of obesity. Obesity increases one's risk of cardiovascular disease, cancer, diabetes, and obstructive pulmonary disease—among the most common and most deadly diseases today. Medical practitioners have tried to determine how much food is adequate to support healthy living. People who consume too much food and become obese may seek medical treatment to lose weight and treat diseases resulting from obesity. Treatments may include nutritional therapy, exercise programs, drug therapy, or surgery. Foodborne illness results from eating contaminated food. Foodborne illness can be caused by parasites, bacteria, viruses, toxins, or other pathogens that are harmful to humans. Food is not the direct cause but rather the carrier of the problematic agent. The effects of foodborne illness can range from flulike symptoms to death depending on the type of pathogen and the amount of exposure. Foodborne illnesses are generally prevented by appropriate growing, harvesting, packaging, preparation, cooking, and storage of food. However, many countries lack the technology and resources necessary to accomplish this. Thus, assuring food safety continues to be an area of international concern.

Food as a Treatment

Food is not only necessary to sustain health but it can also help ill people regain health. Although the common advice to "feed a fever" may sound like folklore it is actually based in scientific evidence. A rise in body temperature is required in order to fight disease. People with a fever also require extra energy if they are to have adequate energy to maintain their strength while they battle illness. Likewise, the immune system uses a wide range of nutrients to combat intruders. All infectious diseases result in increased need for nutrition to strengthen the immune system as if fights against invading viruses or bacteria. People who suffer from diseases such as cancer, cystic fibrosis, and acquired immunodeficiency syndrome (AIDS) generally require extraordinarily large amounts of nutrients to battle their disease. Likewise, young children who are ill require extra food to ensure that they have adequate nutrition to ensure normal growth and development. Food is crucial in combating both minor and major illnesses.

Many specific nutrients defend against disease. Calcium, a mineral found mainly in dairy products, is critical in the promotion of bone health and protection against osteoporosis. Fluoride, now added as a supplement to most water supplies, is crucial to tooth development. Iron is most commonly found in meats and protects against anemia. Folic acid prevents neural tube defects such as spina bifida in developing fetuses and has recently been found to protect against cardiovascular disease. In fact, almost every vitamin and mineral is known to be critical to one or more life processes. Nutritional specialists and medical practitioners are constantly studying the role each nutrient plays in protecting the body and investigating further possible cures.

See also Dietetics; Digestion; Disease: Metabolic Diseases; Enteral and Parenteral Nutrition; Health and Disease; Hunger, Physiology of; Immune System Regulation and Nutrients; Intestinal Flora; Microbiology; Nutrient-Drug Interactions; Nutrients; Nutrition; Nutritionists; Safety, Food.

Jessica Rae Donze