A new study suggests that extreme malnutrition early in pregnancy may put a child at risk for Alzheimer's Disease decades later. The study begins not in the laboratory, but in the Netherlands during World War II.
At the end of 1944, Nazi occupation forces imposed a five-month food embargo in part of the Netherlands, in retaliation for a Dutch railroad strike aimed at disrupting German troop movements.
During the resulting famine, food rations were as little as 400 calories a day for residents - including pregnant women.
The children of those pregnancies, the so-called Dutch famine birth cohort, have been followed closely in the decades since. Researchers have compared them in a series of studies with a control group of children born immediately before and after, to explore the long-term effects of their mothers' malnutrition during pregnancy.
In the latest research, done when the famine babies were in their late 50s, Susanne de Rooij and colleagues at the University of Amsterdam tested them for early signs of dementia.
They found little difference except in something called the Stroop test. That's a test where you are shown the word for one color printed in a different color, and you're asked to disregard the spelled-out color name and say the color that the word is printed in.
"And we found that the people who were exposed to the famine in the beginning of pregnancy, that they performed worse on these tasks," de Rooij explained. "And we think this is very interesting because a recent study has shown that this is one of the first things that may go wrong when you're developing Alzheimer's Disease later."
A study in the 1970s, when they were young army recruits, found no difference in intelligence between the famine and control groups.
But previous research has show physical health differences including increased obesity, cardiovascular disease, and diabetes among the famine babies.
De Rooij's study wasn't designed to show the specific cause of any differences they discovered, but she says the fact that those most affected suffered malnutrition early in their gestation suggests one possibility.
"We think this is sort of an indication that as the central nervous system is being formed in the first part of pregnancy, that maybe something goes wrong due to the lack of nutrients, that the central nervous system isn't really well constructed or [is] more sensitive to aging. So we think this may be happening, but of course we cannot be sure about that," she said.
Susanne de Rooij says she and other researchers will continue to follow the children of the World War II era famine as they age, to learn more about the effect of malnutrition during pregnancy.
Her paper is published in the Proceedings of the National Academy of Science.