Stay Alert With Phenylalanine - Amino Acids And Their Uses
April 22, 2009 by HealthGuru
Filed under Amino Acids
What Is Phenylalanine And What It Is Used For
Phenylalanine is an essential amino acid, meaning that it is not manufactured by the body, but must be obtained from the diet. It is vital for proper brain function because it contributes to the production of several important neurotransmitters and endorphins. Phenylalanine is also converted into the amino acid Tyrosine. Although tyrosine is usually classified as a non-essential amino acid, it relies on phenylalanine for its creation, so it is considered by some experts to be an essential or ‘conditionally essential’ amino acid. Tyrosine is the precursor to the mood elevating neurotransmitter dopamine. Phenylalanine also aids in the production of norepinephrine and epinephrine, which help regulate moods and contribute to alertness, memory and learning. It is also an ingredient in some psychoactive drugs.
Best Natural Sources Of Phenylalanine
Phenylalanine can be found in abundance in:
- meats
- eggs
- dairy products
- bananas
- oats
- wheat germ
Eating a balanced diet will provide adequate amounts of this amino acid, so supplementation of phenylalanine from a nutritional perspective is not usually necessary.
Phenylalanine Benefits
Because it affects the brain in so many ways, phenylalanine has been successfully used to treat depression and other mental problems. Many people suffering from depression have been found to have low levels of phenylalanine, so it is logical that it would be effective as a treatment for depression. Phenylalanine in its various forms can successfully treat bipolar as well as affective depressive disorders.
Phenylalanine increases the production of endorphins, which are the natural mood elevators that are released when we exercise or experience positive emotions. Endorphins are thought to directly affect our sensitivity to pain, or our awareness of it. As a pain reliever, phenylalanine seems to have the most effect on the pain of musculoskeletal disorders such as multiple sclerosis and firbromyalgia, though it can be helpful for other types of pain such as back pain, arthritis, headaches and menstrual cramps. Phenylalanine has shown to be most effective for pain when combined with other painkillers, particularly opiates.
Phenylalanine Side Effects
Approximately one in ten thousand people in the USA are born with the genetic disorder known as phenylketonuria (PKU). People with this disorder lack an enzyme that enables them to metabolize phenylalanine. Undiagnosed, PKU can cause severe mental retardation, or can contribute to ADD and hyperactivity, learning disabilities and other developmental problems in children. If PKU is diagnosed at an early age, a phenylalanine-restricted and tyrosine-supplemented diet can ensure normal mental development. PKU sufferers can learn about their condition by visiting www.pku.com, the website also allows people to tell their stories and network with others who are living with PKU.
Phenylalanine can cause a severe rise in blood pressure when combined with MAO inhibitors such as phenelzine, tranylcypromine and isocarboxazid. This condition, known as ‘hypertensive crisis’, can lead to heart attack or stroke. People taking these drugs should avoid foods and supplements that contain high levels of phenylalanine. Several other medications have the potential for negative reactions when combined with phenylalanine. It is best to consult your physician before combining any prescription drugs with nutritional supplements.
Is Phenylalanine Deficiency Possible?
If the overall diet is low in protein, a deficiency of phenylalanine and tyrosine can result. Symptoms of deficiency include mental confusion and decreased alertness, anxiety and depression, bloodshot eyes, cataracts, and increase in appetite.
Because phenylalanine is essential for the production of tyrosine, the two amino acids function hand in hand with each other. Deficiency of phenylalanine will result in tyrosine deficiency, and excess phenylalanine will cause tyrosine toxicity.
Phenylalanine Supplementation
Phenylalanine does not need to be supplemented under normal circumstances; because it relies on several other nutrients for processing, taking it alone may result in toxicity if the necessary components are not present. To ensure safety, phenylalanine should be taken with the support of other amino acids in a balanced amino acid complex supplement.
Women who are pregnant or breastfeeding should not take phenylalanine supplements.
The artificial sweetener aspartame (Nutrasweet) is made from a combination of aspartic acid and phenylalanine. Because it is 50% phenylalanine, aspartame is unsafe for pregnant women or people with PKU. Since 1974, when the FDA declared aspartame to be safe, the sweetener has been the subject of controversy regarding its safety. Early studies suggested possible links between aspartame and several types of cancer, but subsequent studies did not conclusively prove those claims. Nonetheless, many manufacturers of diet sodas and other foods have begun to move away from the use of aspartame as an artificial sweetener. Splenda, a sweetener made from sucralose, has emerged in its place.
The debate continues to rage over the safety of aspartame. The anti-aspartame movement lies largely within the holistic community, while the FDA maintains its position that the sweetener is safe. Websites that offer information about aspartame are usually strongly biased toward one side or another of the argument (www.aspartame.net tries to cover the topic from both perspectives, giving a reasonably complete overview of the controversy).
Whether or not to eliminate aspartame from the diet is an individual decision. However, when you consider the rate at which diet sodas and other ‘sugar-free’ foods are consumed in our society the question remains as to what should be considered a safe level. Common sense dictates that too much of anything can lead to an imbalance, regardless of how ‘safe’ it is supposed to be, so it is probably best to use everything in moderation.
Final Thoughts
Most people should be getting all their phenylalanine requirements from diet with supplementation only necessary in special cases.
For the most part the information presented at this website is correct, but the information about aspartame safety being controversial is outdated. All aspartame research prior to 2009 is fatally flawed, because it was all done in a scientifically unacceptable manner. That was established by preliminary work presented at the Society of Toxicology (Seattle) and the American Chemical Society (New Orleans) national meetings in early 2008 and is currently being preparing for regular publication. There it was demonstrated that inappropriate controls were used in all aspartame research starting with the original Searle work and extending through the Soffritti et al work published over the past several years (and even other work thereafter). The standard control-versus-treated animal experiments are simply invalid for aspartame, because aspartame is hydrolyzed to methanol. Methanol has long been known to deplete a vitamin, namely folic acid. No properly done experiment can deplete a vitamin, but all experiments to date have done just that! Hence, both controlled and treated groups of animals must be provided either appropriate supplemental folic acid to counter methanol-induced loss OR both controlled and treated groups of animals must be provided the same intake of methanol, one directly and the other from aspartame. However, direct provision of methanol (given evaporation and other difficulties) is an experimentally more challenging option. No experiments to date have done these experiments correctly; hence all aspartame research is seriously and fatally flawed.
Strong associations are clear between all aspartame animal work and the many consequences of folate deficiency, which include the leukemia/lymphomas and mammary tumors claims reported by Soffritti et al in all their work. The consequences of that poorly controlled work and the folate deficiency that results only for the aspartame treated group is the accrual of homocysteine, because of insufficient methylation of methionine. There is no data suggesting any adverse effect, including those cited here cannot simply and completely be explained by the folate deficiency/homocysteine paradigm. This new information only suggests aspartame is even safer, now that what I have reported above is known to all the regulatory authorities. But folate deficiency amongst the population remains a serious problem
John E. Garst, Ph.D. (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)
(FYI, the author has absolutely no financial or biasing connection with the aspartame, the soft drink or their related industries and has made not one penny from my opposition, unlike many critics on the other side. The author has an undergraduate degree in chemistry (with emphasis in organic and biological chemistry) from the University of Kansas, a Ph.D. in Medicinal Chemistry (Pharmacy) from the University of Iowa, postdoctoral experience at Yale University (Molecular Biophysics & Biochemistry) and two postdoctoral fellowships at Vanderbilt University (physiology-pharmacology (mentor moved), then nutritional toxicology) and taught nutritional toxicology at the University of Illinois (Champaign-Urbana, UIUC) besides having conducted federally funded research at Vanderbilt, UIUC, and at several other universities before recently entering into semi-retirement.)
Thanks for the info, I was not aware of this. I will update the information to reflect these latest findings.