Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS

Rx for Survival — A Global Health Challenge

» skip to the content

Deadly Diseases

Malnutrition

Despite vast stores of surplus food that go unused, more than 850 million people go to bed hungry each night. Malnutrition is a problem of politics, economics, and inequity, and it occurs in wealthy countries as well as poor ones. Approximately nine million of the hungry people are in the developed world; the vast majority, however, are in the developing world.

Poor nourishment increases the risk of dying from pneumonia, diarrhea, malaria, measles, premature birth, and various infections. Malnutrition is an underlying factor in 53 percent of deaths of children under 5.

Especially in developing-country settings and other places where a balanced diet may not be available, to combat malnutrition, experts recommend exclusive breastfeeding for six months; supplementary feeding and continued breastfeeding for two years; nutritional care for sick and malnourished children; and special attention to vitamin A and iron intake for both women and children, and iodine for all household members.

Malnutrition (from the French mal, meaning "bad") doesn't just mean lack of food. It might surprise some to learn that it refers to obesity, too. In addition, malnutrition describes a lack of micronutrients, including a range of vitamins and minerals.

One of the most powerful micronutrients for child survival is vitamin A. Found naturally in eggs, meat, and dark green vegetables, or supplied in vitamin capsules or liquid drops taken orally, vitamin A can improve children's health by preventing deaths caused by diarrheal dehydration and measles. It can also prevent dry eye and nightblindness. Severe deficiencies of vitamin A can ultimately result in total blindness. Vitamin A supplement pills or drops administered twice a year in poor countries were able to avert approximately 400,000 cases of childhood blindness per year. Worldwide, it's estimated that the supplements are boosting children's immune systems and saving up to a million lives a year among children at risk of infectious disease.

Pregnant women also benefit from vitamin A supplements, which help reduce maternal mortality dramatically. In a study done in Nepal, maternal mortality rates dropped by more than one-third when women took vitamin A supplements during their pregnancies. It was famously said by nutritionist EV McCollum, who identified vitamin A in 1913, that "Green leafy vegetables are unbottled medicine." Another promising study shows that vitamin A can also reduce pneumonia-induced deaths among children and adults.

History is full of examples of diseases or conditions stemming from dietary deficiencies. European sailors traveling the seas suffered from scurvy, which manifested itself in skin sores, soft gums, and general weakness and was caused by shortages of vitamin C (ascorbic acid) in their diet. Welcoming sailors as they came into the harbor with bags of lemons, limes, and oranges became a time-honored tradition in many ports of call (and the origin of the British epithet "limey").

Rickets is caused by a shortage of vitamin D and can cause skeletal deformities such as crooked legs and hunchback in infants and young children. Vitamin D occurs naturally in sunlight, dairy products, and fish liver oils. In industrialized nations, synthetic vitamin D is routinely added to dairy products and bread.

Goiter, a large swelling on the neck, can develop from a lack of iodine in the diet. Women with iodine deficiency and goiter are at high risk of giving birth to children who are mentally and physically stunted (cretinism); this remains a major problem in the developing world. In the United States, most salt is iodized, so few people need to take extra measures to include iodine in their diets.

Pellagra, which is characterized by the three "d's" — dermatitis, diarrhea, and dementia — can even cause the fourth "d" — death — if left untreated. Pellagra comes from a severe deficiency of niacin, a form of vitamin B. Weakness and reddened skin are the first indicators, yielding later to the skin crusting and peeling. Between 1914 and 1916, Joseph Goldberger of the U.S. Public Health Service did a series of dietary experiments with volunteer prisoners that ultimately revealed the relationship of pellagra to a diet lacking foods such as green vegetables, meat, and eggs that contain this important vitamin. Niacin is now commonly added to flour and cereal products in the United States and many other countries. Pellagra has dissappeared in these countries.

Folic acid, found in dark green leafy vegetables, strawberries, oranges, and beans — or in multivitamins — can actually prevent neural tube disorders, such as spina bifida in a developing fetus. It's important, however, that a woman takes it before she becomes pregnant as well as early and throughout her pregnancy. After 1998, when folic acid was added to cereals, breads, pastas, and other enriched or fortified grain products, the U.S. rate of neural tube disorders fell 26 percent within three years.

Iron deficiencies can cause severe anemia, especially in pregnant mothers, and are a leading cause of maternal mortality; an estimated 20 percent to 40 percent of maternal deaths worldwide are anemia-related. Even mild anemia causes fatigue, weakness, and loss of concentration. Babies born to underfed or anemic mothers suffer from low birth weight (under 5.5 pounds) and lower resistance to disease and infections.

Neural tube disorders such as spina bifida can actually be prevented in a developing fetus by the intake of folic acid. It's especially important that folic acid, found naturally in dark green leafy vegetables, strawberries, oranges, and beans, as well as in most multivitamins, is taken by a woman before she becomes pregnant as well as throughout her pregnancy. After 1998, when folic acid was added to cereals, breads, pastas, and other enriched or fortified grain products, the rate of neural tube disorders in the United States fell 26 percent within the next three years.

While the diseases and disorders described above generally stem from a lack of nutrients brought on by lack of food, overeating, often a cause of obesity, brings with it a host of problems as well. Obesity is defined as 30 pounds or more over ideal weight and is linked to high blood pressure, stroke, heart disease, diabetes, arthritis, and even some forms of cancer. Worldwide, it's estimated that one billion people are overweight and a third of them are obese. Obesity is a growing problem in nations that are becoming more developed or have a large middle class, such as Mexico and India.

In the United States, 60 percent of Americans are overweight or obese, and 39 percent say they do no physical activity in their leisure time. The U.S. Centers for Disease Control estimates that obesity will kill about 112,000 Americans in 2005. Among American adults, diagnosed diabetes cases have jumped 61 percent since 1991. Type 2 diabetes, which affects 90 percent to 95 percent of people with the disease, is linked to obesity and lack of exercise. Until recently, only 1-2% of children with diabetes had Type 2, no it's estimated that 8% have Type 2.

Experts say that environment plays a major role in obesity: Urbanization means most jobs are nearly free of hard physical labor, and more and more frequently, people rely on driving and not walking as their main means of transportation. Advertising promotes high-calorie and low-nutrient food and drink. Snack machines in schools and offices are a popular destination in busy lives, and restaurants typically offer "super-size" portions. Heavy intake of sugar and corn syrup, coupled with a sedentary lifestyle, are major contributing factors to Americans' current high incidence of obesity. Americans consume an average of 128 pounds of sugar per person, up 27 pounds since the 1970s.

Return to Deadly Diseases

Get Involved

Explore four ways you can fight deadly diseases around the world. Rx for Child Survival.