Cape Town - Malnutrition during pregnancy may affect the health of future generations, not just the child of the malnourished mother-to-be.
New research has shown that environmental factors in the womb do not only give the unborn child a higher chance of certain disorders like liver disease, but the next generation too.
The study (from the field of epigenetics, which is to do with environmental factors causing a change in actual genes) was conducted on mice, but has given scientists evidence to believe that the same happens with human beings.
The researchers restricted the caloric intake of the pregnant mice during the last week of pregnancy, and found that the baby mice were at first growth restricted and had low birth weight, but then went on to become obese and diabetic as they aged. Then, in a domino effect, the offspring of the growth-restricted mice also inherited a predisposition to metabolic abnormalities.
“Such a change affects gene activity without changing the DNA’s underlying sequence,” said principal researcher Josep Jiménez-Chillarón.
The findings indicate that in a foetus’s reproductive cells, in utero malnutrition causes epigenetic changes that are subsequently transmitted to cells of the next generation.
“If these findings hold true for humans, what a woman eats while pregnant may have some effects on health and disease in her future grandchildren,” he said.
It also corroborates evidence from previous chapters in history: During the Dutch famine of 1944, pregnant women gave birth to children who were smaller than the previous averages. That didn’t surprise doctors. But, when the children grew up and had their own children who were also smaller than average, it became clear that some type of epigenetic changes had passed down to the next generation.
This is of concern in South Africa where many pregnant women do not eat what they should for optimal nutrition during pregnancy.
According to Michael Hendricks, an expert from the School of Child and Adolescent Health at UCT: “Lack of access to food and micronutrients – such as iron – and exposure to infection such as HIV/Aids during pregnancy can result in maternal under-nutrition and low birth weight, which in turn contribute to underweight and stunting in children.”
And, he added: “The underlying determinants of malnutrition in childhood include food insecurity, inadequate maternal care, insufficient health services and an unhealthy environment.”
Jiménez-Chillarón notes that it is important not to fall into the temptation of “blaming” one’s parents (or even grandparents) for disease as one’s own lifestyle is still the primary factor.
“Our view is that we inherit some predisposition, but it is our own lifestyle that will determine whether inherited risk will truly translate into disease,” he said.
“A healthy lifestyle is the best way to prevent any potentially inherited or newly acquired obesity or diabetes predisposition.”
Severe lack of nutrition in babies on the rise in SA
Severe acute malnutrition in children younger than 12 months is increasing in South Africa, says Michael Hendricks of the School of Child and Adolescent Health at UCT.
“This points to poor infant feeding practices, most notably inadequate or no breastfeeding, the early introduction of other fluids and food before the age of six months, and inappropriate diets for older children.”
Recently, government policy has focused on exclusive breastfeeding and counteracting the marketing put out by companies which produce formula.
But, says Marion Stevens, co-ordinator at Wish (Women in Sexual and Reproductive Rights and Health Associates), it is important to understand the contextual issues when it comes to messaging around breastfeeding.
“There are layers of complexity,” she says, “and it is important to make it very clear that exclusive means “absolutely exclusive”. If there is anything else, like the mother chewing meat and putting it in the baby’s mouth, or introducing solids too early, the breastfeeding isn’t going to do what it should.”
She also noted that formula feeding had, in some communities, become a type of status symbol. “It is an aspirational thing, associated with middle class living. But, fortunately, government has been increasing its messaging around breastfeeding…”
Another major concern was that urban pregnant women’s diets “are shocking” and that research had shown that proportions of fruit and vegetables eaten during pregnancy had declined over the years.
According to Louise Kuhn, an epidemiologist from Columbia University currently doing research in South Africa: “People sometimes think that formula feeding is only dangerous when women do not have access to clean water or if they are uneducated. But this is not true.”
Even when women had access to clean water and were well-educated, the risk of a baby dying if he or she was formula-fed was about twice as high as if he or she were breastfed.
But if there was no clean water, the risk of a baby dying if he or she was formula-fed was about six times higher than if he or she was breastfed.
Cape Times