In 1984 a British doctor noticed a curious relationship between the elevated death rate among newborn babies in an impoverished region in the 1900s and a high incidence of heart disease in the same area decades later. What piqued David Barker’s interest was that neonatal mortality is a sign of poverty, but heart disease is considered an affliction brought on by an affluent, cholesterol-rich and high-stress lifestyle.

Perhaps, thought Dr Barker, the search for the causes of heart disease should not just focus on adult proclivities to exercise little, eat too much rich food and poison the body with nicotine and alcohol. Perhaps it should begin much earlier, when a cluster of tiny, nutrient-hungry cells begins the process of dividing and subdividing to form a human being.

Thus began an epidemiological revolution that has profound implications for our ageing world. "Advances in public health, better nutrition and improved immunization mean that more babies survive into adulthood," says Prakash Shetty, an FAO nutritionist. "But we have compelling evidence to show that undernutrition in the womb could sentence adults to a life of vulnerability to diseases like heart disease, cancer, diabetes and obesity."

Ripe old age for some – a rotten future for others

These are debilitating, chronic diseases that require much more extensive health care systems than exist in developing countries. Moreover, these diseases undermine a person’s capacity to work and a nation’s ability to create such systems. As Gro Harlem Brundtland, head of the World Health Organization (WHO), told the recent World Assembly on Ageing in Madrid, "While the developed countries became rich before they became old, developing countries will become old before they become rich."

If current trends continue, the Madrid conference heard, the world will see a 300 percent increase in people over the age of 60 over the next half-century -- outnumbering the world’s youth. Most of these people will be concentrated in developed countries, but developing nations will see the same or higher rates of increase – meaning that societies already weakened by poverty and AIDS will be expected to bear the added burden of geriatric diseases with fewer resources. "And fewer resources mean poorer foetal nutrition, perpetuating this dangerous cycle," says Dr Shetty.

And it gets worse.

Rerouting the roadmap of life

"Undernutrition seems to affect the physiology of the growing foetus, influencing its genetic blueprint," says Dr Shetty. "The deleterious effect is not as clear-cut as, say, that of smoking on foetal health, whereby toxins impede cell division and growth. An undernourished foetus adapts to the environment in the womb in a much more subtle way that affects the baby even if it subsequently gains weight."

The relationship between low birth weight and high infant death rates is well known. "Full-term babies who weigh below 2.5 kg at birth are much more likely to die within their first few months than heavier babies," says Dr Shetty.
"But what is surprising is that foetal adaptations to gestational conditions seem to be permanent. Even if a baby is born with adequate weight, if it was significantly undernourished during gestation, the damage may have already been done."

In the 1960s, researchers studying prenatal nutrition found that a foetus deprived of nutrients early in gestation, but adequately nourished later on, grew into an adult with an increased risk of obesity. "It seems that they developed thrifty phenotypes," says Dr Shetty. "These geared the metabolism to conserve every calorie and to direct available nutrients to the brain at the expense of other organs. This also increases the risk of diabetes in middle age."

These other organs include the liver, which has an important role in regulating cholesterol, the heart and the kidneys. "Each of these organs has a critical growth period," says Dr Shetty. "If the foetus is starved of nutrients during that period, its response is to slow the rate of cell division in that organ."

Lifestyle choices?

Developing countries face another demographic change that also affects foetal nutrition – urbanization. By the end of the decade, more than half the world’s population will be living in urban areas, most of them in developing countries, where they will have to deal with changing diets.

"The rapidly expanding urban middle class in developing countries is especially prone to chronic, degenerative diseases," says Dr Shetty. "It’s not just that they are eating more Western food and smoking, but they are living long enough for the dietary errors of the past to catch up with them."

These dietary errors are caused by maternal malnutrition. And this is why FAO is working with WHO and the United Nations Children’s Fund to promote better nutrition for pregnant women. "It’s an axiom of development to say that women are the linchpin of sustainable growth," says Dr Shetty. "The research on foetal undernutrition reinforces that message, because what hunger does to a foetus will shackle the adult to ill-health for life."