Most pregnant women know that they avoid certain foods and drinks, such as raw meat and alcohol. But a new study gives weight to the notion that high intake of caffeine-containing substances could also be detrimental to a baby's health.
The study published Monday in the journal BMJ Open found that excess intake of caffeine during pregnancy was associated with excess growth during the first year of life of the child and an increased risk of being overweight eight years later – both is associated with an increased risk of obesity later in life, according to Eleni Papadopoulou, a researcher at the Norwegian Institute of Public Health and a lead author of the study
"We considered it very important to assess the impact [of caffeine] on the growth of infants because fast infant growth is very consistently associated with the development of childhood obesity and even adulthood, "Papadopoulou wrote in an e-mail. "In other words, children and adults who grow more rapidly in infancy than peers have a higher risk of being overweight or obese."
The study examined more than 50,000 women from all over Norway who were recruited from the Norwegian mother-child cohort study between 1999 and 2008. Women's caffeine intake was reported once during pregnancy – at 22 weeks – and the child's growth patterns were 6 Weeks to 8 years recorded. Based on self-reported nutritional data, caffeine intake was considered low (0-49 milligrams / day), average (50-199 mg / day), high (200-299 mg / day), or very high (300 or more mg / Day). Possible sources of caffeine were coffee, black tea, caffeinated soft drinks, chocolate, chocolate milk and some types of sweets.
For reference, a cup of caffeine-flavored 8 oz. Coffee usually contains between 100 and 150 milligrams of caffeine, and an 8-ounce cup of black tea or cola has between 25 and 50 milligrams of caffeine, according to the Mayo Clinic.
"It is important for pregnant women to be aware that caffeine not only comes from coffee, but that caffeine-containing soda drinks can also contribute with significant amounts of caffeine," wrote Papadopoulou. "The current recommendation for pregnant women should not exceed 200 mg caffeine intake per day, which is about 2-3 cups of black coffee, based on all scientific evidence on the negative effects of caffeine on pregnancy outcomes such as miscarriage and fetal growth restriction."
The researchers found that women who had a very high intake of caffeine during pregnancy, increased by 66% were at risk of having a child with overgrowth in the first year of age, compared with women who had low caffeine intake. Excess growth was defined as a weight for age greater than the 75th percentile for that age.
Women who had an average or high intake of caffeine also had a 10% and 30% increased risk, respectively is an important finding, since about 75% of women during pregnancy and also because of pregnancy coffee with excessive growth during childhood drinking obesity problem, "said Dr. De-Kun Li, a reproductive and perinatal epidemiologist in the research department of Kaiser Permanente Northern California, who was not involved in the recent study.
"For childhood obesity, there are many risk factors that occur during pregnancy," Li added.
In addition to over-growth in infancy, the study also looked at this The study of whether children who were exposed to very high levels of caffeine during pregnancy became more likely to become overweight in childhood s exposure to average, high and very high caffeine content in utero is associated with a significantly higher risk of obesity at the age of 3 years and 5 years.
"Our findings indicate that high maternal caffeine intake during pregnancy was related to overgrowth of childhood and childhood obesity later in life, and the results support current recommendations to limit caffeine intake during pregnancy to less than 200 mg Caffeine per day, which is about 2-3 cups of coffee … (but) we also found associations with caffeine intake below 200 mg, "said Papadopoulou.
However, at the age of 8 years, an increased risk of obesity was found only in children exposed to very high levels of caffeine. In particular, these children weighed on average 213 grams (7.5 ounces) more at 3 years, 320 grams (11.3 ounces) more at 5 years, and 480 grams (16.9 ounces) more at 8 years old than children who were low Caffeine levels were exposed
"When you're about 10 years old, all other factors are added to determine obesity, especially diet and exercise," Li said. "Physical inactivity like games, computers and television all come into play and can overburden the internal mechanism due to caffeine intake during pregnancy. "
This is not the first time that caffeine intake during pregnancy has been associated with adverse health outcomes in children. A 2008 study showed that women who consumed more than 200 milligrams of caffeine per day had miscarriages more than twice as often as those without caffeine intake.
A 2015 study reported that exposure to caffeine was associated with utero in 87% increased risk of childhood obesity
But the new study first studied the effects of caffeine at low 50 milligrams per day. According to Papadopoulou, it is also one of the first to examine growth rates in the first year of life.
"Our findings on caffeine intake and rapid growth in infancy are new," she said. "The finding that caffeine intake in the area of recommendations was linked to excessive infant growth was also a bit surprising."
The mechanism linking caffeine exposure to increased childhood growth has not been fully elucidated. Caffeine is known to cross the placenta and has been associated with decreased fetal growth during pregnancy, which is also known as "intrauterine growth restriction," according to a 2001 study.
According to Li, caffeine could affect the development of the hypothalamus – pituitary axis in the brain, which regulates many hormones responsible for the growth and development of infancy, resulting in decreased uterine growth and increased growth after the birth leads.
"We know that caffeine affects the baby's brain function … Hypothesis is very plausible," Li said. "We know that caffeine affects the neurotransmitters that affect the brain, and we know everything during the fetal period happens, is reinforced and can be long-lasting. "
In 2010, the American College of Obstetricians and Gynecologists reported consuming less than 200 milligrams of caffeine per day during pregnancy is not associated with adverse health effects and evidence supporting the consumption of more than 200 milligrams of caffeine per day Day associated with decreased fetal growth are inconclusive.
But not everyone agrees with the current position of the organization.
"I did not like that idea," Li said, "I think the idea should be as little as possible (caffeine) drink, do your best, and if you can not, you absolutely should not go over 200 milligrams."
The new study was based on self-reported data from a racially and ethnically homogenous population – one of the main limitations of the study, according to Li.
According to Tom Sanders, professor of nutrition and dietetics at King's College in London, the not involved in the study, it also did not control breastfeeding, which is known to affect childhood growth rates.
But the results add that increased caffeine intake during pregnancy could have long-term adverse effects on the baby's health, according to Papadopoulou.
"Our findings support the current recommendation as caffeine intakes above 200 mg / day were not exceeded