A growing body of research finds that many health problems in adulthood and old age stem from infections and health conditions early in life. Some researchers argue that important aspects of adult health are determined before birth, and that nourishment in utero and during infancy has adirect bearing on the development of risk factors for adult diseases—especially cardiovascular diseases. Early malnutrition in Latin America is highly correlated with self-reported diabetes, for example, and childhood rheumatic fever is a frequent cause of adult heart disease in developing countries.
Research also shows that delayed physical growth in childhood reduces physical and cognitive functioning in later years. Data on China’s oldest old show that rarely or never suffering from serious illnesses or receiving adequate medical care during childhood results in a much lower risk of suffering cognitive impairments or physical limitations at ages 80 or older.
Proving links between childhood health conditions and adult development and health is a complicated research challenge. Researchers rarely have the data necessary to separate the health effects of changes in living standards or environmental conditions during a person’s life from health effects related to his or her birth or childhood diseases. However, a Swedish study with excellent historical data concluded that reduced early exposure to infectious diseases was related to increases in life expectancy. A cross-national investigation of data from two surveys of older populations in Latin America and the Caribbean also found links between early conditions and later disability. The older people in the studies were born and grew up during times of generally poor nutrition and higher risk of exposure to infectious diseases. In the Puerto Rican survey, the probability of being disabled was more than 64 percent higher for people growing up in poor conditions than for people growing up in good conditions. A survey of seven urban centers in Latin America and the Caribbean found the probability of disability was 43 percent higher for those from disadvantaged backgrounds than for those from more favorable ones (Figure 7).
If these links between early life and health at older ages can be established more directly, they may have especially significant implications for less developed countries. People now growing old in low- and middle- income countries are likely to have experienced more distress and disadvantage as children than their counterparts in the developed world, and studies such as those described above suggest that they are at much greater risk of health problems in older age, often from multiple noncommunicable diseases.
Behavior and exposure to health risks during a person’s adult life also influence health in older age. Exposure to toxic substances at work or at home, arduous physical work, smoking, alcohol consumption, diet, and physical activity may have long-term health implications.
Figure 7. Probability of Being Disabled among Elderly in Seven Cities of Latin America and the Caribbean (2000) and Puerto Rico (2002-2003) by Early Life Conditions
Source: Monteverde M, Norohna K, Palloni A. 2009. Effect of early conditions on disability among the elderly in Latin-America and the Caribbean. Population Studies 2009;63/1: 21-35.