Student Article High School Science Journal Author: Brooke Hollyfield

The Effect of Cholesterol on Fetal Alcohol Syndrome

August 05, 2007

Previous to March 2007, fetal alcohol syndrome (FAS) was deemed an unfortunate, devastating, and irreversible disease that resulted from a mother’s consumption of alcohol during pregnancy.  However, a recent study of zebrafish confirming the role of cholesterol to fetal development may have opened a door into the prevention of this once incurable disease. 

       Fetal alcohol syndrome is caused by the effect of the mother’s consumption of alcohol on the developing fetus.  It is a lifelong condition, characterized by mental retardation and physical birth defects.  The physical problems include abnormal features, growth deficiencies, and a dysfunctional central nervous system.  Children may also acquire FASD, which is not as severe as FAS, but includes learning disabilities and behavioral disorders.  FAS is said to occur .2 to 1.5 times per every 1000 births in the United States.  The syndrome is not rampant, but certainly deeply impacts those affected.  Until very recently, the only way to prevent FAS was to not consume alcohol during pregnancy.  However, it has recently been discovered that the link to preventing the effect of alcohol on fetal development lies in none other than cholesterol. 

      It has always been a known fact that cholesterol is essential to the metabolic processes involved in fetal development.  Pregnant women with low cholesterol levels risk having children with birth defects.  In fact, the average 3.2 kg infant needs 8 grams of cholesterol during the nine month gestation period for the brain and body developments to occur and function correctly.  In early development the yolk sac facilitates the transfer of cholesterol between the mother and the fetus.  After four weeks, the placenta replaces the yolk sac as the barrier between the mother and fetus.  Cholesterol is taken up by lipoprotein receptors on the maternal side of tropoblasts then progresses to fetal circulation.  However, the placental transfer which offers the necessary and beneficial cholesterol to the fetus is also permeable to the harmful and potent alcohol.  When alcohol permeates into fetal circulation, it blocks the receptors for cholesterol in the fetus.  During the rapid periods of growth when cholesterol is necessary for the proper development of the fetus this can be devastating.  Insufficient supplies of cholesterol lead to abnormal development of the body and central nervous system, the characteristics of FAS.  Until very recently the effects were irreversible and unpreventable once the alcohol was confused.

      However, a recent study of zebrafish by Dr. Yin-Xiong at Duke University may provide hope to fetuses exposed to alcohol.  In the experiment, they exposed zebrafish fetuses to alcohol causing an onset of FAS.  But, when they injected the fish with cholesterol, the embryo returned to normal.  The alcohol that interfered with vital metabolic pathways leading to fetal development did not have as prominent effects when extra cholesterol was supplemented. 

      Although Dr. Yin-Xiong’s findings certainly offer no excuse for consuming alcohol during pregnancy, he has opened the door to further research and hopefully prevention of FAS.  Injections of cholesterol may soon be used to combat the effects of alcohol on the developoing fetus.  Perhaps this early prevention will lead to the eradication of fetal alcohol syndrome altogether.  In a country where 100 children are born with FAS each day, any new finding, even if beginning in zebrafish, should be fully explored to benefit those who suffer from fetal alcohol syndrome.   
 

http://www.brightsurf.com/news/headlines/29264/Cholesterol_could_be_key_to_treating_fetal_alcohol_syndrome.html

http://www.cdc.gov/ncbddd/fas/fasask.htm 

http://www.ajcn.org/cgi/content/full/82/6/1155 

 
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