I learned about Phenylketonuria in my prenatal class, when I was pregnant. PKU is a genetic disease in which the gene that codes for a certain protein (an enzyme) that enables one to break down the amino acid, phenylalanine is defective. As a result, this amino acid accumulates and becomes toxic to the brain. Left untreated it can quickly result in severe and permanent mental disability. Although the incidence of PKU is only one in ten thousand births, all fifty states have laws requiring newborns to be tested for this genetic disease. That is because the effects of untreated PKU are devastating but completely preventable with treatment. Detection is simple -- they prick the heal of the newborn, and get a small blood sample. If the blood has high levels of phenylalanine this is considered positive for PKU. The treatment then is a strict, low protein diet for the rest of one's life.
Unfortunately the timing of when this test is done most of the time, increases the risk of a false negative -- meaning there is the possibility of NOT identifying a baby with PKU. Babies born to vegan mothers may even be at INCREASED risk of being falsely told their baby does not have PKU, because the vegan diet...
Unfortunately the timing of when this test is done most of the time, increases the risk of a false negative -- meaning there is the possibility of NOT identifying a baby with PKU. Babies born to vegan mothers may even be at INCREASED risk of being falsely told their baby does not have PKU, because the vegan diet...
is naturally lower in phenylalanine (especially if one does NOT consume Nutrasweet.) it takes at least 24 hours of exposure to enough phenylalanine-rich protein, before a baby's blood will develop high enough levels of phenylalanine to be detected on this test. Hospitals are required to do the test before releasing a newborn baby, but insurance companies encourage the release of new baby prior to when the test is more likely to be accurate. Because a vegan diet may be naturally lower in phenylalanine, a vegan mother nursing her baby means her baby will have some protection from the harms of PKU which is good, BUT it also means it could take longer for enough phenylalanine to build up in the baby's blood to trigger a positive result on this test.
In fact the "treatment" for PKU is pretty nearly a vegan diet, except beans and nuts are avoided too. Babies are supplemented with a special mixture of vitamins and a small amount of protein which has had the phenylalanine removed. Below is how parents are taught to feed their child with PKU. Basically they can eat unlimited fruits and vegetables, and small amounts of grains, potatoes and peas. Meat, dairy and eggs are NOT allowed at all. (Keep reading past the image -- there's important stuff to follow...)
In fact the "treatment" for PKU is pretty nearly a vegan diet, except beans and nuts are avoided too. Babies are supplemented with a special mixture of vitamins and a small amount of protein which has had the phenylalanine removed. Below is how parents are taught to feed their child with PKU. Basically they can eat unlimited fruits and vegetables, and small amounts of grains, potatoes and peas. Meat, dairy and eggs are NOT allowed at all. (Keep reading past the image -- there's important stuff to follow...)
About one in fifty adults are considered to be silent "carriers" of PKU. Because it takes two copies of the defective gene to produce full-blown PKU, if both parents are silent carriers, they have a one in four chance with each pregnancy of having a child with PKU.
But lessor-known studies suggest that even carriers -- that is the 2% of the population who carry a single defective copy of the PKU gene, generally assumed to be fully capable of detoxing excess phenylalanine from their body, may experience elevations in phenylalanine levels when they consume a lot of protein, and this study showed they had increases from consuming Nutrasweet. We know from adults with PKU, that when their levels of phenylalanine begin to increase, their first symptoms are changes in mood and a decreased ability to focus and concentrate. It is possible that in those who carry only a single copy of the PKU gene, a higher protein diet may similarly impact them.
The interesting thing here however is that we now have examples of many people, consuming low-protein diets from infancy on (who have been diagnosed with PKU) living long full lives with notable physical and intellectual achievements. So the next time, someone tries to tell you that a vegan diet, which is usually lower in protein than one that includes daily consumption of meat, dairy and eggs is dangerously low in protein, you can point out how those with PKU seem to lead full lives while intentionally restricting their protein levels to much less than what most vegans typically consume.
But lessor-known studies suggest that even carriers -- that is the 2% of the population who carry a single defective copy of the PKU gene, generally assumed to be fully capable of detoxing excess phenylalanine from their body, may experience elevations in phenylalanine levels when they consume a lot of protein, and this study showed they had increases from consuming Nutrasweet. We know from adults with PKU, that when their levels of phenylalanine begin to increase, their first symptoms are changes in mood and a decreased ability to focus and concentrate. It is possible that in those who carry only a single copy of the PKU gene, a higher protein diet may similarly impact them.
The interesting thing here however is that we now have examples of many people, consuming low-protein diets from infancy on (who have been diagnosed with PKU) living long full lives with notable physical and intellectual achievements. So the next time, someone tries to tell you that a vegan diet, which is usually lower in protein than one that includes daily consumption of meat, dairy and eggs is dangerously low in protein, you can point out how those with PKU seem to lead full lives while intentionally restricting their protein levels to much less than what most vegans typically consume.
