The global epidemic of noncommunicable disease: the role of early-life factors.

The rapid increase in prevalence of noncommunicable diseases (NCDs) is probably the most important global health problem of the 21st century. Already in every region except Africa, NCDs account for greater mortality than communicable, maternal, perinatal and nutritional conditions combined. Although modifiable lifestyle behaviors in adult life are the main risk factors, substantial evidence now suggests that factors in early life also have a major role in the development of NCDs. For instance, breastfeeding and a slower pattern of infant weight gain have been shown to reduce the risk of obesity, cardiovascular disease and diabetes in both low-income and high-income countries. The mechanisms involved are poorly understood, but include epigenetic changes and resetting of endocrine systems that affect energy metabolism and appetite. These early life factors may interact with and exacerbate the detrimental effects of a sedentary lifestyle and energy-dense diets later in life. As a consequence, the impact of early-life factors on long-term health may be particularly important in low- and middle-income countries, which face the fastest increases in urbanization and greatest changes to lifestyle. Strategies to optimize infant nutrition could therefore make a major contribution to stemming the current global epidemic of NCD.