The quality of prenatal and infant nutrition has long-lasting consequences, according to two recent studies—a fact retailers can use to promote sound nutrition among pregnant women and new mothers.
One study, reported in the July issue of Stroke, published by the American Heart Association, found that hunger and poor nutrition during pregnancy are strongly correlated with stroke later in life. "It looks like an ecological association," said Daniel Lackland, M.D., a professor of epidemiology at the Medical University of South Carolina and co-author of the study.
Lackland compared notes with David Barker, a British physician with the University of Southampton, and the pair found that each country had regions with an unusually high incidence of strokes. Barker found that many adults who had strokes during the 1960s and '70s were born in industrial towns in Wales and northern England during the 1910s and '20s to mothers who suffered poor nutrition and overcrowded living conditions.
In the southeastern United States, stroke rates are 10 percent to 60 percent higher than the national average. The high stroke rate can't be explained merely by lifestyle: People who were born elsewhere and later moved to the South don't show the same incidence rate. And, said Lackland, "We focused our particular case on the Medicaid population, so we felt we controlled" for socioeconomic status and access to medical care.
Barker and Lackland theorized that perhaps prenatal nutrition was at play in the United States' "stroke belt" as well. Indeed, poverty was rampant and birth weights were low in the South in the years between the Civil War and the Great Depression. "It's not just low birth weight; that doesn't make sense at all," said Lackland. "We're not undernourished; we're malnourished."
The results don't suprise Sam Russo, N.D., LAc, of the Brattleboro, Vt., Naturopathic Clinic. "If there's a nutritional deficiency while the baby is growing, it's just going to get compounded" later in life, he says. But because the study was retrospective, it's impossible to say which nutrients were lacking in prenatal diets.
Still, a few nutrients are always critical prenatally, says Russo. "One aspect is going to be folic acid and B-12. [They're] necessary for cell division." Russo says tissue-building proteins, along with omega-3 fats, are also important.
There are a few theories about how in utero malnutrition could lead to strokes in adults. One theory posits that poor nutrition leads to reduced fetal growth. Blood flow is directed primarily to the brain and away from vital organs, establishing permanent changes in arterial structure. Strokes occur when blood flow to the brain is interrupted, usually because of a blood clot.
Another possibility could be that low-birth-weight babies have fewer nephrons, or blood-filtering units, in their kidneys than do healthy infants. The nephrons they have are overworked, which leads to high blood pressure and, eventually, stroke. The New England Journal of Medicine in January published a report that seems to support this theory. In that study, scientists found that people with high blood pressure had fewer than half as many nephrons as people with normal blood pressure.
Lackland also sees a correlation of poor prenatal nutrition with diabetes and hypertension. "If you're a small baby, you have a slightly less developed system. If you stay lean and fit throughout your childhood, adolescence and early adulthood, there's no problem. If you're a small baby and you overload the calories at an early age, it seems like it magnifies the risk beyond what you see with simple obesity."
An animal study also highlighted the probable connection between poor nutrition in early life and health problems later in life. Scientists at Glasgow University in Scotland found that when zebra finches were given diets low in vitamins and protein early in life, they lived fewer years relative to control-group finches, even though both groups appeared healthy as adults.
Natural Foods Merchandiser volume XXIV/number 8/p. 14