Morning sickness can be miserable, but it may serve the valuable purpose of keeping your diet as healthy as possible for your growing baby. (Not to mention, morning sickness might make your baby smarter.)
A British study concluded that how much nausea a pregnant woman experiences may depend on how nutritiously she eats. University of Liverpool scientists analyzed 56 studies on morning sickness and found that symptoms were linked to higher intake of sugars, sweeteners, alcohol, caffeine and meat and to lower consumption of cereals.
This study supports other research on what is known as "gestational food aversion." The idea is that pregnant women may avoid certain foods because of nausea and thus protect the fetus from potentially unhealthy substances. For example, before the invention of refrigeration, meat often carried harmful bacteria. Thus, women may be genetically programmed to be sensitive to meat during pregnancy. Likewise, alcohol is known to be toxic to a fetus.
"If you consider all the available evidence, there is a positive function for normal levels of nausea and vomiting," says Samuel Flaxman, Ph.D., an evolutionary biologist at Princeton University who has studied the connection but was not involved in the British research. "While certain foods may set it off, [morning sickness is] still highly individual," he adds. "A woman may be sick eating fried fish and OK with a hamburger."