In future, so-called "Western" chronic diseases in adults could be prevented by strategies that focus on the nutrition of young women and their babies.
That is if public health stakeholders take note of the groundbreaking research that is being done by Prof David Barker of the MRC Environmental Epidemiology Unit in Southampton, United Kingdom.
Chronic adult diseases, like heart disease, hypertension and diabetes, account for 60% of deaths worldwide every year. These diseases formed the basis of several important lectures and symposia at the recent 18th International Congress of Nutrition in Durban, South Africa.
One of the key discussions at the Congress pointed to strong evidence that chronic disease in adults may have its origins not only in foetal life, but also in the early years of life.
While a series of genes have been shown to play a role during development, the expression of these genes can be influenced by several factors, experts believe. "What a gene does is conditional in terms of the circumstances during development," Barker says.
And it is here that nutrition – both of the mother and the young child – comes into play.
Strategies to ensure survival
One of the hypotheses holds that in critical periods of nutritional deprivation, the foetus adopts strategies to ensure survival. When undernourished, the foetus doesn't surrender growth as his first option. Instead, his body makes metabolic adaptations – with adverse consequences.
"An increased allocation of energy to one trait, such as brain development or growth of the body, must reduce allocation to one or more traits. This is a law of nature," Barker says.
In small babies, an example is the reduced allocation of energy for the development of skeletal muscle. Insulin resistance and arterial elasticity can also get the short end of the stick in the case of undernutrition – a situation which can result in the development of diabetes and heart disease in later life.
"Adaptations made during early development tend to have 'permanent' effects on the body's structure and metabolism – a phenomenon referred to as 'foetal programming'," Barker says in a newsletter insert of the Danone Institute for Nutrition and Health.
The foetus may either change the nutrients it consumes to get energy, or alter the production of hormones, including insulin, which regulate growth or redistribute blood flow to protect key organs.
Importance of growth patterns
Another hypothesis that is of particular interest is how the pace of growth during the first few years of life can impact on the individual's health – and risk of chronic disease – in later life.
A study that traced 15 000 people born in Helsinki during World War II set out to determine whether pace of growth made a difference in babies who were of low birth weight. Records of height and weight from birth to puberty were studied.
The researchers found that the boys who developed heart disease in later life were thinner than their peers at the age of two.
Later research indicated that low birth weight and being underweight at age two is also a strong predictor of insulin resistance.
The researchers believe that children who are thin at the age of two, and then put on weight rather rapidly, are metabolically incompetent – a situation that puts them at risk for insulin resistance in later life. Insulin resistance is linked to the development of diabetes.
Another example is that of babies born during a period of famine in Holland – also at the end of World War II. Even though the babies' weights weren't markedly affected by the reduced nutrition, many of these kids grew into adults who now suffer from overweight and insulin resistance, according to Barker.
The mother's body composition is also likely to be of importance to the baby, Barker says. A Chinese study found that the offspring of thinner mothers were more insulin resistant.
Barker says more needs to be done to ensure varied and balanced nutrition in mothers before conception and during pregnancy; that there should be greater protection of the growing infant; and that rapid weight gain should be prevented in young children – especially if they were of low birth weight. – (Carine van Rooyen, Health24)
Read more about healthy eating during pregnancy.