Amino acids are so vital to our health that even deficiency in one amino acid can have serious repercussions for physiological function. Serine is one of the 20 amino acids necessary for healthy functioning of the human body and is classified as a nonessential amino acid. Serine deficiency is associated with serious conditions like metabolic diseases and congenital microcephaly. Even though your body can synthesize its own serine, a certain level of dietary intake is important for optimal neurological health.
Let’s take a closer look at serine, its biological function, and what to do in the case of deficiency.
Serine Is Your Body’s Neuroprotector
L-serine designates a specific configuration of the serine molecule that is extracted from food or synthesized in your cells. L-serine supports cell growth and proliferation and plays a particularly important role in neurological processes.
Consider an everyday movement that you do, such as waving hello at someone. This may seem like a pretty simple, automatic task; however, the neurotransmission involved in simply lifting your hand is complex. Your brain transmits messages through the central nervous system, through the nerves in your hand to initiate a movement. L-serine is responsible for form structures important for neurotransmission. L-serine also forms phospholipids, which are important structural elements of myelin, which protects the transmission of electrical signals through the central nervous system. Myelin can be compared to the protective coating on electrical wiring; without it, brain messages wouldn’t travel to their destination.
Furthermore, L-serine is a precursor for glycine (which is another amino acid) and D-serine, both of which regulate NMDA receptor activity in the brain. L-serine is a component of phosphatidylserine, which is found in brain tissue and regulates the passage of neurotransmitters across the cell membrane. Developing fetuses rely heavily on serine for proper central nervous system development.
Amino acids don’t operate in isolation and are often used in the production of other amino acids. Serine is crucial for synthesizing other amino acids like tryptophan, glycine, and cystine. Interruption in serine levels can impact levels of these amino acids.
Signs of Serine Deficiency
Based on the numerous important roles that serine plays in neurological function, L-serine deficiency results in neurometabolic disorders and symptoms can have a detrimental impact on cognitive and psychomotor function.
Serine benefits cognitive health. Cognitive decline. impact neurotransmission,
If you suspect you may have a serine deficiency, your doctor can test levels of serine in plasma or cerebrospinal fluid.
What Causes L-Serine Deficiency?
The severity of symptoms can be associated with the underlying cause of deficiency; while symptoms of congenital serine synthesis disorders are severe, diet-induced deficiency tends to exhibit in milder forms.
Congenital Serine Deficiency Disorders
Serine deficiency disorders result from inborn errors in the genetic coding for the enzymes responsible for serine biosynthesis. Enzymes are proteins that facilitate biochemical reactions, and our body uses enzymes to convert a starting product into a biologically useful compound. Glycine (a different amino acid) or another compound called 3-phosphoglycerate are the key compounds that are used in l-serine synthesis.
The congenital deficiency disorders usually arise from an absence of one of the three enzymes used to convert 3-phosphoglycerate into L-serine. These three enzymes are:
- 3-phosphoglycerate dehydrogenase (3-PGDH)
- Phosphoserine aminotransferase (PSAT)
- Phosphoserine phosphatase (PSPH).
These disorders result in severe neurological symptoms including intractable seizures, microcephaly, cognitive and motor deficits, and abnormal myelination. Congenital serine deficiency is usually diagnosed in infancy or early childhood.
Research has shown that congenital disorders can usually be treated successfully with serine supplements.
Diet-Induced Serine Deficiency
In the absence of a congenital disorder, serine deficiency in the general adult population is usually a result of inadequate dietary serine intake. Even though you’re body can make enough serine to function, this doesn’t mean that you have ideal levels for optimal functioning. Dietary adjustments may help protect against neurological symptoms associated with serine deficiency and help you feel your best.
Benefits of Serine: What the Research Shows
One particularly compelling study published in the Current Nutrition Reports journal evaluated the diet of Ogimi villagers, located in Okinawa, Japan. The people of the Ogimi village are known for their longevity and low rates of neurodegenerative disease, which prompted researchers to evaluate the amino acid profiles of foods in the Ogimi diet. Results showed that Ogimi villagers consume a diet high in amino acids. In particular, serine consumption was about double that observed in the standard American diet. Foods characteristic of the Ogimi diet include varied species of marine algae and tofu.
In another study, administering l-serine to aging mice helped reduce inflammation and oxidative stress in the hypothalamus. Other outcomes included decreased body weight and suppressed appetite. Though exact mechanisms are unclear, one study revealed that L-serine plays a role in restructuring damaged neural proteins, which may play a role in mitigating the symptoms of neurodegenerative disorders.
Making Sure You Have Enough Serine
To make sure you have optimal levels of serine in your body, it’s important to adjust your diet to incorporate serine-rich foods. Though you don’t have to eat like an Ogimi villager to get optimal levels of serine, ensuring adequate intake may take a little conscious planning.
Here are some excellent sources of serine:
- Soy products like tempeh and tofu
- Asparagus
- Spices like fenugreek and white mustard seeds
- Cauliflower
- Spinach
- Beef
- Chicken
- Fish
- Eggs
Vitamin B6 Is Needed to for L-Serine Biosynthesis
Vitamin B6 or pyrixodine– is a facilitator of serine synthesis. Vitamins and minerals often serve as supporters of enzyme activity, and are known as cofactors. You can think of Vitamin B6 as a key that unlocks an enzyme and allows it to perform at full capacity.
Therefore, it is critical that you consume adequate levels of vitamin B6. Here are a list of foods that contain vitamin B6:
| Chickpeas | Beef liver |
| Yellowfin tuna | Chicken breast |
| Salmon | Breakfast cereals |
| Potatoes | Banana |
| Ground beef, patty | Cottage cheese |
| Winter squash | White rice |
| Nuts | Raisins |
| Watermelon | Onions |
| Spinach | Tofu |
Supplementing with Serine
Few l-serine side effects have been reported, and supplementing has been shown to be safe.
Serine: Summarized
Serine is a nonessential amino acid, and your body is able to synthesize a certain amount to use for cellular processes. However, this doesn’t mean that your body has enough serine for optimal function. Incorporating serine-rich foods into your diet can protect against neurodegenerative diseases and help you feel clear-headed. If you are facing a serine deficiency, consuming serine in your diet or supplementing is critical.
