Caffeine consumption during pregnancy is not associated with pre-term birth

Posted on November 4, 2010 by Dr. Jonathan

The notion that caffeine consumption during pregnancy is a risk factor for pre-term birth does not hold up in an extensive meta-analysis published in the American Journal of Clinical Nutrition. The authors state:

“The effect of caffeine intake during pregnancy on the risk of preterm delivery has been studied for the past 3 decades with inconsistent results…We performed a meta-analysis examining the association between caffeine consumption during pregnancy and risk of preterm birth.”

They identified 15 cohort and 7 case-control studies that met inclusion criteria among MEDLINE and EMBASE articles published between 1966 and July 2010. What did the data show?

“The combined odds ratios (ORs) obtained by using fixed-effects models for cohort studies were 1.11, 1.10, and 1.08 for risk of preterm birth comparing the highest with the lowest level of caffeine intake (or no intake)during the first, second, and third trimesters, respectively. Results for the case-control studies yielded no associations for the first, second, or third trimesters.”

In other words, as they state in their conclusion, no statistically significant risk from caffeine consumption emerged from the data:

“In this meta-analysis, we observed no important association between caffeine intake during pregnancy and the risk of preterm birth for cohort and case-control studies.”

Coffee and tea can reduce type 2 diabetes: more evidence

Posted on January 5, 2010 by Dr. Jonathan

Yet more research, this time a meta-analysis published in Archives of Internal Medicine that accepted data from 18 studies with information on 457,922 patients. They found that “every additional cup of coffee consumed in a day was associated with a 7% reduction in the excess risk of diabetes…” They go on to conclude: “Similar significant and inverse associations were observed with decaffeinated coffee and tea and risk of incident diabetes. High intakes of coffee, decaffeinated coffee, and tea are associated with reduced risk of diabetes.” HOWEVER: those individuals who have a common Th2-type autoimmune disorder or severe sympathetic nervous system hyperarousal can be made worse from these beverages.

Coffee and tea reduce risk of type 2 diabetes

Posted on December 26, 2009 by Dr. Jonathan

This paper published in the journal Diabetologia may contradict some assumptions. The investigators set out to “examine the association of consumption of coffee and tea, separately and in total, with risk of type 2 diabetes and which factors mediate these relations.” Their findings may be a surprise to some: “Total daily consumption of at least three cups of coffee and/or tea reduced the risk of type 2 diabetes by approximately 42%.” They go on to conclude: “Drinking coffee or tea is associated with a lowered risk of type 2 diabetes, which cannot be explained by magnesium, potassium, caffeine or blood pressure effects. Total consumption of at least three cups of coffee or tea per day may lower the risk of type 2 diabetes.” How can this be? There are compounds in both beverages that have anti-inflammatory and other beneficial effects. As you know, chronic inflammation plays an important role in type 2 diabetes. HOWEVER: bear in mind that caffeine can aggravate Th2-type autoimmune conditions, and it may be poorly tolerated by those with sympathetic nervous system hyperarousal.