“Poor diet, infection, stress, and poverty can lead to stunts, and there is an important link between growth and animal food consumption,” said Christine Stewart, director of the Institute for Global Nutrition at UC Davis and associate professor in the Department of Nutrition.
Take eggs, for example. Stewart and a team of scientists worked with malnourished children in the highlands of Ecuador and found that infants grew significantly stronger when mothers supplemented their diet with an egg every day.
“We saw infants who received an egg daily for six months had a nearly 50 percent decrease in stunt performance compared to those who didn’t,” said Stewart, who is also the Corinne L. Rustici Endowed Chair of applied human nutrition at UC Davis is.
Egg yolks are rich in choline, an essential nutrient that supports liver function and the healthy development of the brain, muscles and nervous system. Choline is absent from the standard diet of many impoverished Ecuadorians who mainly eat rice, potatoes, and thin soup.
Stewart’s team tried to replicate the results in a similar experiment using infants living in Malawi. The test site was near Lake Malawi, Africa’s second largest lake with an enormous variety of freshwater fish. Interestingly, eating an egg every day did not affect the child’s growth.
“Fresh fish is such a nutritious food that the Malawian families we have worked with are likely already getting more nutritional quality in their diets than they are in the highlands of Ecuador,” Stewart said.
Fish, eggs, meat, and other animal foods are beneficial, but not just because of the protein they provide. Most children get enough protein. Instead, stunted and other malnourished children experience what nutritionists call “hidden hunger” – chronic deficiencies in iron, iodine, zinc, choline, vitamin B-12 and other micronutrients necessary for healthy brain growth and development.
For children in developing countries, food from animal sources provides many essential micronutrients that are difficult to find only from plants. Iron is a good example. Children need iron when their brain, muscles, and blood cells grow. A 12 month old child needs 11 milligrams of iron per day, and 8 milligrams for adults. Gram per gram, you would have to eat eight times more spinach than liver and four times more spinach than beef to get the same amount of iron.
“That’s because iron and other micronutrients in foods of animal origin are more concentrated and bioavailable, which means that our bodies can absorb them more easily,” said Stewart. “What you ingest is just as important as what you consume.”
The meat connection
Fifteen years ago, CA&ES researchers conducted what remains the most influential experiment on the role of animal nutrition in improving growth, physical activity, and cognitive development in children. The Global Livestock Collaborative Research Support Program, led by former CA&ES professor of plant science, Tag Demment, supported a five-year project in Kenya that enrolled more than 1,000 children – some were given two ounces of beef on school days, some were not. Lindsay Allen, research professor at the UC Davis Department of Nutrition, helped lead the study.
Over five years, children who regularly ate meat scored 20 percent more points on cognitive tests, spent more time managing, and were more physically active than children who did not. The children’s muscle mass increased significantly and their vitamin B-12 deficiency was eliminated.
“This landmark study shows that food quality is more important than quantity and shows the relationship between foods of animal origin and child development,” said Stewart.
However, in some developing countries, beef is not easy to come by. It can be expensive to buy and difficult to transport and sell. “There are many food safety concerns with meat in open air markets unrefrigerated,” said Stewart. “If families can afford a cow, they are more likely to keep it for milk or use it to till the land. It may be more practical to include milk, eggs, and fish in your diet. ”
For this reason, Stewart and other international nutritionists are responding to world hunger with a variety of nutritional measures, including supplementing diets with a variety of foods from animal sources.
“When children eat diets that are high in vitamins, minerals, and essential fatty acids, they have a greater chance of survival and thriving,” said Stewart. “Animal foods are an important way to provide children with the nutrients they need.”