Serine is one of the non-essential amino acids that your body needs in metabolism. Non-essential means, your body can make the amino acids without the need to obtain from food. In 1865, Cramer obtained the first serine from silk thus the name serine from Latin “sericum” that means silk. Later in the early 20th century, Fischer and Leuchs synthesized the compound.
Types of Serine
Derived from glycine, this amino acid consists of two isomers (chemicals with the same formula but with different properties and atomic arrangements in the molecule) – L-serine and D-serine. The L-serine is available as a dietary supplement while D-serine is not. The Federal Drug Administration classifies L-serine as generally regarded as safe (GRAS) while D-serine is not.
Important Functions of Serine
Some of these benefits may or may not have evidence or may need further clinical trials and studies to confirm its efficacy.
- Plays as a precursor of other amino acids such as Cysteine and Glycine. That means, the two amino acids need serine for their formation.
- Plays an important part in forming phospholipids that form the membrane and the structural integrity of the cell.
- Helps in the proper function of DNA.
- Constitutes an important ingredient to produce an essential amino acid – Tryptophan.
- Supports in absorbing creatine for building and maintaining muscles.
- Assists in the making immunoglobulins that are proteins made by lymphocytes and plasma cells. They act as antibodies to fight fungus, bacteria and viruses.
- May treat Amyotrophic Lateral Sclerosis that is a rare neurological disease characterized by falling, tripping and loss of motor control in arms and hands. The possible beneficial effects of L-serine still needs further clinical testing.
- Supports the central nervous system. It optimizes the myelin sheath (a protective covering surrounding the nerve). (2)
- May support in lowering Fibromyalgia which is a chronic disorder characterized by fatigue, disturbance in thinking, and pain. The effect of this amino acid still needs more research and clinical trials to confirm the efficacy. (3)
- May benefit people with myalgic encephalomyelitis or chronic fatigue syndrome – a disease in the nervous system.
- Symptoms insomnia, nausea, problems in neurocognition, blood pressure and weight change. Some studies show that people suffering this disease have lower its levels although further clinical trials and investigations are needed to confirm the efficacy of serine. (4)
Effects of L-serine on Cognitive Disorders
Dementia and Alzheimer’s disease
Currently, a phase 2 clinical trial is underway to test whether this amino acid would benefit patients with early-stage Alzheimer’s disease. Some preclinical trials told that the amino acid may prevent our bodies from mistakenly recognizing beta-methylamino-L-alanine BMAA as L-serine and use it in proteins. The misappropriation of BMAA instead of L-serine in proteins causes cell death. However, researchers still need further clinical trials and studies to confirm the efficacy of this amino acid. (5)
According to a study by Japanese researchers, this amino acid may benefit people affected by poor sleep. Their findings suggested that it improved nighttime sleep by taking it consecutively. (6)
Chronic Fatigue Syndrome (CFIDS)
In February 1998, the Collaborative Pain Research Unit (CPRU) of Newcastle University discovered that some CFIDS patients have this. The CPRU doctors made a study on determining the anomalies found in the urine of CFIDS patients. The doctors confirmed that CFIDS patients have low levels of serine in urine. (7)
Foods High in Serine
Although your body can make this amino acid, you can obtain it further from the following food sources (from top to least) :
- Egg white
- Soy protein isolate
- Dried seaweed and spirulina
- Soy protein powder
- Sesame seeds and flour
- Soy flour
- Peanut flour
- Dried and salted cod
- Cottonseed flour
- Pork skin
- Parmesan cheese
- Raw and matured soybeans
- Sunflower seed flour
- Dried-frozen tofu
- Meat extender
- Yeast and leavening agents
- Matured seeds of lupin
- Romano cheese
- Roquefort cheese
- Gruyere cheese
- Hemp seed
- Pumpkin seeds
- Peanut flour
- Swiss cheese
- Cured Pork
- Mixed nuts
- Edam cheese
- Gouda cheese
- Round Beef
- Watermelon Seeds
- Fontina cheese
- Caraway cheese
- Provolone cheese
- Peanut butter
- Game meat
What are the effects of D-Serine on cognitive disorders?
D-serine supplements can reduce the symptoms associated with cocaine use and may moderately benefit schizophrenia patients. (8) For detailed studies about its effects on schizophrenia, here is the link. (9)
What are the limitations and caveats?
Studies and findings greatly support the benefits of this amino acid. However, there are still needed clinical trials to confirm some of its benefits. Such unclear benefits include the effects of this amino acid on ALS patients, the benefits of serine supplements, the effects on pregnant women, the effects of combining L and D-serine.
Are there any drug interactions?
No effects have been reported although it’s best to consult your doctor before supplementing your diet with this amino acid.
What is the recommended dosage?
Dosage between 500 and 2,000 mg. Excessive intake of this amino acid may promote cancer growth because it’s one of those that promote cancer growth. (10)
1 – Top Food Sources of Serine, foodinfo.us/SourcesUnabridged.aspx?Nutr_No=518.
2- Amino Acid L-Serine in Preventing Neurodegenerative Diseases Associated with BMAA, www.pharmacytimes.com/contributor/adam-remick/2017/09/amino-acid-l-serine-in-preventing-neurodegenerative-diseases-associated-with-bmaa.
3 – McGregor, N R, et al. “Preliminary Determination of a Molecular Basis of Chronic Fatigue Syndrome.” Biochemical and Molecular Medicine, U.S. National Library of Medicine, Apr. 1996, www.ncbi.nlm.nih.gov/pubmed/8733884.
4- Yunus, M B, et al. “Plasma Tryptophan and Other Amino Acids in Primary Fibromyalgia: a Controlled Study.” The Journal of Rheumatology, U.S. National Library of Medicine, Jan. 1992, www.ncbi.nlm.nih.gov/pubmed/1556707.
5- Amino Acid L-Serine in Preventing Neurodegenerative Diseases Associated with BMAA, www.pharmacytimes.com/contributor/adam-remick/2017/09/amino-acid-l-serine-in-preventing-neurodegenerative-diseases-associated-with-bmaa.
6 – Ito, Yukihiko, et al. “Effects of L-Serine Ingestion on Human Sleep.” SpringerPlus, Springer International Publishing, 22 Aug. 2014, www.ncbi.nlm.nih.gov/pmc/articles/PMC4155056/.
7 – Addington, John W. “L-Serine: Treatment for Chronic Fatigue Syndrome (CFIDS).” Prohealth, 21 Mar. 2018, www.prohealth.com/library/l-serine-treatment-for-chronic-fatigue-syndrome-cfids-11562.
8 – Patel, Kamal. “Studies Related to Cognition and D-Serine.” Examine.com, Examine.com, examine.com/rubric/effects/view/e7faaf9c623d05c8009130c5e181aa10/33225e5170c0e6998053253d0571713e/all/.
9- Patel, Kamal. “Studies Related to Symptoms of Schizophrenia and D-Serine.” Examine.com, Examine.com, 25 May 2014,examine.com/rubric/effects/view/e7faaf9c623d05c8009130c5e181aa10/7507cdeb105755c2c882135a943a22df/all/.
10- Serine and glycine metabolism in cancer, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3989988/