Category Archives: Pregnancy

Phenylalanine amino acid: Importance of PKU Screening in Newborn Babies

In the United States a heel stick test (using a needle prick on the baby’s heel for a small blood sample) is done at the ripe old age of 3 days old to test for Phenylketonuria (PKU) and other disorders. PKU is a metabolic disorder that shows up when the gene is inherited from both parents of the newborn, which is an enzyme deficiency that is needed for proper metabolism of the amino acid phenylalanine.

People with PKU must avoid foods that contain phenylalanine altogether from birth, however, in order to survive since side effects can include pigmentation loss in the skin/eyes/hair, a “mousy” odor, muscles pains and aches, seizures, and mental retardation.

Newborn screening and phenylalanine-restricted diets for PKU patients

Phenylalanine is an essential amino acid that is in foods, including proteins like meats, dairy products, beans, eggs, tofu, nuts, and many others, including aspartame (the sugar substitute in diet soda). An “essential” amino acid means that the body cannot produce this amino acid on its own so it must be gotten from food. Aminos phenylalanine and tyrosine are both associated with PKU and are tested for in all newborn babies at clinics and hospitals.

According to the American Academy of Family Physicians, it is Dr. Richard Koch from the University of Southern California School of Medicine in Los Angeles, California, who promotes that repeat testing should occur in any child that tests positive for PKU. The amino acid phenylalanine in foods should be avoided and a special diet should begin from birth so as to prevent mental retardation.

Koch says, “Occasionally, cases of PKU are missed by newborn screening. Thus, a repeat PKU test should be performed in an infant who exhibits slow development.”

Phenlyketonuria (PKU) is a recessive defect in the enzyme phenylalanine hydroxylase

Koch discusses the enzyme deficiency: “Phenylketonuria (PKU) is caused by an autosomal recessive defect in the enzyme phenylalanine hydroxylase, which is required for converting phenylalanine to tyrosine. (Five percent of natural protein is composed of phenylalanine.)”

PKU is caused by a mutation that is located on chromosome 12, although the specific type of mutation may vary, which results in severity that is variable among those with the PKU disorder. Phenylalanine containing foods should be avoided in all of these cases. Of course, normal people who do not have PKU need phenylalanine and should have a diet consisting of enough proteins to provide this essential amino acid.

References:

www.nlm.nih.gov/medlineplus/ency/article/001166.htm

http://www.aafp.org/afp/1999/1001/p1462.html

Connection between Folic Acid and Amino Acid Homocysteine

There is a connection between folic acid and amino acid homocysteine, but what is it? Folic acid and amino acid (homocysteine, one of the 22 amino acids) functions are quite different, but the former does affect the latter. In fact, blood levels of homocysteine in the body are lowered in the presence of folic acid.

Folic acid is also known as folate; however, folate is slightly different. Folate—a bioavailable and natural form of vitamin B9—comes from the word ‘foliage’ because it is found in leafy greens, such as spinach and other greens, but also from fortified/enriched cereals and animal foods like eggs or liver, as well as plant foods like broccoli, brussel sprouts, lentils, beans, asparagus, cantaloupe, and bananas. Folic acid is merely the synthetic form of folate, and is found in supplements.

Folic acid/folate (vitamin B9) helps the body produce energy, is needed for mental and emotional health, and helps prevent neural tube birth defects like spina bifida, which occurs during the first month of pregnancy, especially in high risk pregnancies. Folic acid deficiencies can occur in people due to alcoholism, celiac disease, and inflammatory bowel disease.

The terms (and products) folic acid and amino acid are two different things; where folic acid is vitamin B9, and amino acids like homocysteine, cysteine, leucine, lysine, carnitine, and so on, are simply the building blocks of proteins. All 22 common amino acids are found in protein foods such as meats (chicken, pork, beef, etc.) as well as fish and eggs. Eggs, then, are actually a good source of both folic acid and amino acid content.

So what is the connection between folic acid and amino acid homocysteine?

Although amino acids are necessary for health, sometimes it is not good to have too much of a good thing; homocysteine is one of these amino acids where elevated blood levels of the amino acid can actually cause health problems.

According to Dr. Weil, elevated homocysteine levels are “linked to an increased risk of heart attacks and strokes. Elevated homocysteine levels are thought to contribute to plaque formation by damaging arterial walls. High levels may also act on blood platelets and increase the risks of clot formation; however, whether high levels of homocysteine actually cause cardiovascular disease has yet to be agreed upon. … In addition, some evidence suggests that people with elevated homocysteine levels have twice the normal risk of developing Alzheimer’s disease.”

The folic acid and amino acid connection is affected by diet as well. People who eat a lot of meat in comparison to leafy greens (that have folate/folic acid) or fruits tend to be highest in homocysteine levels. B vitamins and folic acid help reduce homocysteine levels. Additionally, says Dr. Weil, “homocysteine is also produced in the body from another amino acid, methionine. One of methionine’s main functions is to provide methyl groups for cellular reactions. … Typically, homocysteine then receives another methyl group from either folic acid or vitamin B6 to regenerate methionine.”

Folic acid supplements usually come in .4 to .8 grams, but prescription strength is at 1 g/day, although older pregnant women or high risk moms can take up to 4+ g/day (doctor prescribed). If you are low in folic acid and amino acid levels supplements can be taken for either. High stress and increased coffee consumption can also raise homocysteine levels, however. Homocysteine levels can also be elevated due to psoriasis, kidney disease, or even low thyroid hormones.

Other than talking with your doctor, one of the best ways to deal with the folic acid and amino acid connection, especially if there is an issue, is to eat healthy, get enough exercise, and make sure your daily diet includes plenty of leafy greens and fresh fruits and vegetables and less meat and fried foods, which may also reduce cholesterol and aid cardiovascular health as an added bonus.

Sources:

http://umm.edu/health/medical/altmed/supplement/vitamin-b9-folic-acid

http://www.drweil.com/drw/u/ART03423/Elevated-Homocysteine.html