Phenylalanine is an essential amino acid, meaning that it is necessary for human health but is not produced by the body. As L-phenylalanine (LPA), it is one of the twenty common amino acids. In 1959, Marshall Warren Nirenberg discovered the genetic codon for phenylalanine.
Since it is not produced by the human body, phenylalanine is obtained through the diet. Some foods rich in phenylalanine include:
Chickpeas (garbanzo beans)
Egg (yolk, white or whole)
Lentils (dry and whole)
|Milk (sheep, goat, mother’s milk)
Peanuts (roasted with skins)
Phenylalanine may also be obtained through supplements.
A phenylalanine deficiency may occur when sufficient amounts are not given to the body. Some symptoms may include:
- Decreased alertness
- Lack of energy
- Loss of muscle
- Lowered appetite
- Memory troubles
- Stunted growth
L-phenylalanine is the natural form of phenylalanine. Along with UVA radiation, it has shown a return of pigment to white areas in patients with vitiligo.
D-phenylalanine is a synthesized form. It is thought to stimulate nerve pathways, therefore assisting in the reduction of chronic pain in some medical conditions. It is also thought to assist in walking and speech difficulties, and depression found in Parkinson’s disease.
DL-phenylalanine is a combined form of both D and L. It is claimed to have pain-killing and anti-depressant benefits.
Phenylketonuria, also known as PKU, is a genetic disorder regarding an individual’s inability to properly metabolize phenylalanine. Persons with phenylketonuria (phenylketonurics) need to avoid phenylalanine intake, including aspartame, a well-known artificial sweetener.