Recent studies suggest that a mother’s food habits during pregnancy have an impact on her child’s future food preferences.
More and more often, we are seeing reports from scientists that high-sugar and high-fat foods influence the reward pathways in the brain – in essence, these foods have addictive properties. Human brain imaging studies have confirmed that overeating and addictive eating behaviors are associated with abnormal brain activity in dopamine reward circuits, and this is similar to the activity characteristic of drug addiction.1-3
One recent study has taken this data a step further – they have shown that consumption of a high-sugar, high-fat diet (junk food diet) by pregnant rats actually affected the development of the reward system in the brains of their pups. When given a choice between standard food and junk food, the pups whose mothers were fed junk food chose to consume more junk food than other pups.4
These food preferences may be learned by the fetus through its developing sense of smell. The development of the smell-processing area of the mouse pup’s brain (called the olfactory bulb) is influenced by scents that are concentrated in amniotic fluid, and these scents are determined in part by the mother’s diet. In another recent study, a more flavorful diet containing stronger scents given to pregnant and nursing mice resulted in enhanced development of the olfactory bulb in their pups. Also, when given a choice of food, these pups had a strong preference for the same diet their mothers had, whereas other pups had no preference.5
These studies suggest that a mother is actually able to “teach” her babies which foods are desirable based on what she eats during pregnancy and nursing.
Earlier studies found additional detrimental health effects on rat pups whose mothers ate a junk food diet (a diet composed of high-sugar, high-fat foods designed for human consumption) during pregnancy and nursing: these pups were more likely to be obese, were subject to more oxidative stress, were more likely to develop non-alcoholic fatty liver disease, and had impaired muscle development.6-9 Human studies have shown that parental obesity is associated with obesity at 7 years of age, and gestational weight gain is associated with body mass index at 3 years of age.10, 11 The overall message is that the eating habits of parents significantly affect children.
Of course, we cannot extrapolate the results of animal studies directly to humans. However, these results do highlight the simple fact that the health of a developing baby is closely linked to the health of its mother. Women do require extra calories when pregnant and nursing – we have all heard of the phrase “eating for two.” These studies suggest that if the extra caloric requirement is met with oil-rich processed foods and sugary desserts instead of calorie dense whole plant foods, the baby’s food preferences and long-term health may be affected.
Fetal development is a crucial time – it is common knowledge that pregnant women shouldn’t drink alcohol or smoke, because these things could harm the baby. We know that unhealthy foods are damaging to the health of adult humans, so they are likely also damaging to a developing fetus.
Every expectant mother wants a healthy baby, and in addition to the standard advice to avoid alcohol and cigarette smoke, it would be prudent to avoid unhealthy foods.
1. Stice E, Yokum S, Burger KS, et al: Youth at risk for obesity show greater activation of striatal and somatosensory regions to food. J Neurosci 2011;31:4360-4366.
2. Stice E, Yokum S, Blum K, et al: Weight gain is associated with reduced striatal response to palatable food. J Neurosci 2010;30:13105-13109.
3. Gearhardt AN, Yokum S, Orr PT, et al: Neural Correlates of Food Addiction. Arch Gen Psychiatry 2011.
4. Ong ZY, Muhlhausler BS: Maternal "junk-food" feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring. FASEB J 2011.
5. Todrank J, Heth G, Restrepo D: Effects of in utero odorant exposure on neuroanatomical development of the olfactory bulb and odour preferences. Proc Biol Sci 2010.
6. Bayol SA, Farrington SJ, Stickland NC: A maternal 'junk food' diet in pregnancy and lactation promotes an exacerbated taste for 'junk food' and a greater propensity for obesity in rat offspring. Br J Nutr 2007;98:843-851.
7. Bayol SA, Macharia R, Farrington SJ, et al: Evidence that a maternal "junk food" diet during pregnancy and lactation can reduce muscle force in offspring. Eur J Nutr 2009;48:62-65.
8. Bayol SA, Simbi BH, Fowkes RC, et al: A maternal "junk food" diet in pregnancy and lactation promotes nonalcoholic Fatty liver disease in rat offspring. Endocrinology 2010;151:1451-1461.
9. Bayol SA, Simbi BH, Stickland NC: A maternal cafeteria diet during gestation and lactation promotes adiposity and impairs skeletal muscle development and metabolism in rat offspring at weaning. J Physiol 2005;567:951-961.
10. Reilly JJ, Armstrong J, Dorosty AR, et al: Early life risk factors for obesity in childhood: cohort study. BMJ 2005;330:1357.
11. Oken E, Taveras EM, Kleinman KP, et al: Gestational weight gain and child adiposity at age 3 years. Am J Obstet Gynecol 2007;196:322 e321-328.