Eating nuts during early pregnancy may boost a child’s cognitive ability, according to a new study by researchers in Spain.
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According to the study, children born to mothers who consumed 2 to 3 ounces of nuts per week during the first trimester of pregnancy typically scored higher on I.Q., memory and attention tests, compared with women who did not eat nuts.
Previous research has shown that eating nuts is associated with a reduced risk of hypertension, diabetes and oxidative stress. Some researchers also suspect nut consumption may help to protect against cognitive decline during old age. However, this is first study to investigate whether eating nuts during pregnancy can improve children’s cognitive performance.
Nuts and I.Q.
For the study, Jordi Julvez (Barcelona Institute for Global Health) and colleagues assessed 2,208 women and their children over an eight-year period. The mothers completed validated food frequency questionnaires during the first and third trimesters of pregnancy and children were assessed for motor and cognitive ability at 1.5, 5 and 8 years of age.
As recently reported in the European Journal of Epidemiology, children born to mothers who had consumed three or more servings of nuts (including walnuts, hazelnuts, almonds, peanuts, and pine nuts) during the first trimester scored higher on intelligence tests than those born to mothers who had not eaten nuts.
The scientists adjusted the results for factors such as maternal age, education, smoking habits, socioeconomic status, alcohol consumption and various other characteristics.
Compared with children born to mothers who ate no nuts, children who were within the highest one-third for maternal nut consumption (an average of 74 grams per week) during the first trimester scored significantly higher on tests for sustained attention, working memory and I.Q.
However, eating nuts during the third trimester showed weaker associations with improved test performance.
Maternal dietary preferences ‘can have long-term effects’
Nuts are high in folic acid and fatty acids, including omega-3, which have been proven to have beneficial effects on health and cognitive ability. Julvez and team believe that these nutrients accumulate in the neural tissue of the developing fetus during crucial early developmental stages.
The brain undergoes a series of complex processes during gestation and this means that maternal nutrition is a determining factor in fetal brain development and can have long-term effects.”
Florence Gignac, First Author
Folic acid, for example, has been shown to significantly reduce the risk of neural tube defects such as spina bifida developing during the first trimester. It may also confer protection against other birth defects such as cleft palate, limb and heart defects and the development of brain tumors during childhood.
Similarly, omega-3 has been proven to help fetal brain development and research has shown that taking these fats during pregnancy can improve learning and coordination. Omega-3 also reduces the likelihood of obesity in childhood and later life, according to research.
Furthermore, a 2017 study published in the journal Translational Psychiatry showed that deprivation of omega-3 and omega-6 during the early stages of pregnancy had long lasting effects on offspring. The study identified a molecular cascade linking the nutritional environment to risk for schizophrenia.
Schizophrenia and omega-3
The link between omega-3 and omega-6 was supported by research by scientists at the RIKEN Brain Science Institute in Japan, who deprived pregnant mice of the two fats to see whether their offspring developed schizophrenia-like behaviors in later life. Such symptoms include low motivation, impaired memory, abnormal function in the prefrontal cortex and depression. This was shown to be true and related to the downregulation of specific genes that support the development of oligodendrocytes (the brain cells that surround neurons and aid signal transmission in the brain).
‘Eat nuts three times a week’
The American College of Obstetricians and Gynecologists approves of women eating nuts during pregnancy due to their protein content but makes no claims about the effect this has on neurodevelopment.
Julvez says that while the study cannot explain the differences in effect between maternal first and third-trimester nut consumption, the scientific literature suggests that the pattern of fetal development varies throughout pregnancy, with some stages being particularly sensitive to maternal diet.
He adds that this is the first time he and his colleagues have observed this effect, which is insufficient to inform any changes to guidelines.
We need to replicate these results in other populations. Still, I would recommend that women eat nuts at least three times a week, especially almonds, walnuts and hazelnuts.”
Gignac, F., et al. Maternal nut intake in pregnancy and child neuropsychological development up to 8 years old: a population-based cohort study in Spain. Eur J Epidemiol (2019). https://doi.org/10.1007/s10654-019-00521-6