Christy GoffMaternal Infant Nutrition 2012

CAFFEINE INTAKEDURING

PREGNANCY

What is caffeine?

• Bitter, white crystalline xanthine alkaloid that acts as a stimulant drug• Methylxanthine

• Found in seeds, leaves and fruits of plants, where it acts as a natural pesticide• We get it from tea, coffee, cocoa, colas and energy drinks

• Most frequently ingested pharmacologically active substance in the world• 80% of women drink caffeine-containing beverages daily [1].

• 70-95% of pregnant women drink caffeine-containing

beverages daily [5].

Caffeine Sources:

Hinds TS, West WL, et al. 1996. The Effect of Caffeine on Pregnancy Outcomes Variables. Nutrition Reviews; 54(7): 203-207.

Caffeine Metabolism--Metabolized in the liver into three primary metabolites

http://en.wikipedia.org/wiki/Caffeine#Metabolism

Caffeine Metabolism• Potential Sites of Action [2]:• Blockade of adenosine receptors (A1 & A2a)• Blockade of phosphodisesterases • Effects ion channels (regulating intracellular levels of

calcium causing muscle contractions)• Absorbed within 45 mins of ingestion, peak blood

concentration at 1 hour • Clearance in pregnant woman is longer [5]

• Complete metabolism varies in individuals due to age, liver function, enzyme activity, hormonal and medication activity. [1]

• Metabolites released through the kidneys

Health Concerns• Caffeine is readily absorbed into the human

placenta• Diffuses into breast milk• Breaches blastocyst and may accumulate in

the fetal brain [2]

• Caffeine been associated with:• Delayed Conception [1]

• Spontaneous abortion or miscarriages in first trimester [5]

• Fetal growth restriction [4]

• Low birth weight and preterm delivery• In animal studies: Disturbances in development of central

nervous system - Neutral tube [1]

Nutritional Concerns

• Overall Macro & Micronutrient status• Women at risk: little education, low

socioeconomic status, and those with present nutritional deficiencies

• Calcium: • Study by Harris, S concludes postmenopausal

women who have lower Ca intakes than the RDA may be at risk for increased bone loss with 2-3 servings of coffee/d. [6]

• Increases urinary calcium excretion for 1-3hrs after ingestion

• Causes nervous system stimulation, cardiac muscle stimulation, smooth muscle relaxation, increasing gastric acid secretion & increases free fatty acids and glucose in blood plasma [7].

• Fetal brain is more sensitive to caffeine than an adult brain [2].

• Caffeine exposure could presents certain dangers to neurodevelopment during the critical growth period [2].

Caffeine’s Overall Effects

Current Research and Recommendations

• FDA and ADA recommends not exceeding 300mg of caffeine per day while pregnant. [8]

• Mayo clinic recommends consuming less than 200mg of caffeine per day [3]

Alternative approaches• Education and counseling: caffeine is sometimes not perceived

as a substance of abuse

• Choose organic, fair trade brands to minimize chemical processing

Challenges in data collection

• Experimental studies on pregnant women are unethical • Relies on retrospective data, subjected to recall

bias [5].• Finding an accurate assessment of caffeine intake

from subjects• Differences in individual tolerance for caffeine• Not looking at confounding factors (alcohol

consumption, smoking, other dietary habits, pregnancy symptoms )

References:[1] Krzysztof, KM. 2009. Caffeine in pregnancy. Arch. Gynecol Obstet; 280: 695-698. [2] Nehlig, Astrid. Coffee, tea, chocolate and the brain. CRC Press. Boca Raton, FL: 2000.[3] Pregnancy week by week. Mayo Foundation for Medical Education and Research. May 2011. http://www.mayoclinic.com/health/pregnancy-nutrition/PR00109/NSECTIONGROUP=2 Accessed Oct 2012.[4] Boylan S, et al. 2008. Maternal caffeine intake during pregnancy and risk of fetal growth restriction: a large prospective observational study. BMJ; 3(337): a2332.[5] Xiaoping W., et al. 2008. Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study. Am J Obstet Gynecol; 198:279e1-279e8. [6] Harris S.S., Dawson-Hughes B. 1994. Caffeine and bone loss in healthy postmenopausal women. Am J Clin Nutr; 60:73-578.[7] Hinds TS, West WL, et al. 1996. The effect of caffeine on pregnancy outcomes variables. Nutrition Reviews; 54(7): 203-207.[8] ADA Reports. 2008. Position of the American Dietetic Association: Nutrition and lifestyle for a healthy pregnancy outcome. Journal of Am Dietetic Association; 108 (3): 553-561.