It has been demonstrated that the natural amino acid L-tryptophan, which is involved in the creation of the hormone serotonin and is present in many proteins, can lessen arousal and stress.
Niacin, which is necessary for the production of the neurotransmitter serotonin, is also produced by tryptophan. Serotonin aids with mood and sleep regulation. The hormone responsible for transferring signals between nerve cells.
L-Tryptophan and D-Tryptophan are the two different forms of tryptophan. The orientation of the molecule is the only distinction between the two types. Tryptophan can be obtained through specific meals and supplements. It is present in various high-protein foods, such as milk, chicken, eggs, cheese, and fish.
Health benefits of L-Tryptophan for dogs
Giving your pet an L-tryptophan supplement has a range of health advantages, including improving sleep quality, relieving sadness or anxiety, and enhancing mental wellbeing. L-tryptophan is a natural amino acid, so it won’t harm your dog’s organs while helping to enhance behaviour.
If your dog or cat becomes anxious easily, giving them a calming substance containing L-tryptophan may help them overcome a shortfall by preserving their serotonin levels, regaining their mood, and reducing their aggression.
According to studies, tryptophan-deficient dogs are more likely to exhibit aggressiveness, melancholy, and moodiness. This means that L-Tryptophan-based calming supplements are frequently given to dogs who exhibit signs of aggression or anxiety since they can lessen aggressive behaviour and promote calm behaviour.
In pet calming supplements, L-tryptophan is frequently combined with additional all-natural chemicals including GABA, Passiflora Incarnata, and L-theanine to help pets feel less stressed and anxious about behavioural problems.
Veterinarians all across the UK recommend nutracalm if you’re seeking for a soothing supplement for dogs and cats that contains L-Tryptophan. Nutracalm was created with the express purpose of naturally calming anxious pets and assisting in the reduction of undesirable and disorderly behaviour. Without having a sedative effect, nutracalm helps to normalise neurotransmitter activity and lessen mood swings.
Should I offer my dog L-tryptophan in dosages?
For domestic dogs, tryptophan (Trp) is a necessary amino acid (Canis lupus familiaris). For dogs to maintain their basic health, it is advised that they ingest at least 1.1 grammes of Trp per kilogramme of dry matter food, assuming that their diet has an energy density of 4000 kcal of metabolizable energy (ME) per kilogramme (1). Trp supplementation above this threshold is being researched as a way to boost serotonin synthesis, a cerebrospinal fluid neurotransmitter implicated in mood regulation (25). The saturable, rate-limiting enzyme tryptophan hydroxylase produces serotonin in the brain (6,7). Given that this enzyme is only around 50% saturated under physiologically normal conditions, it is likely that increased Trp substrate availability affects the serotonergic pathway and increases serotonin production (811).
Numerous mammalian subjects have demonstrated that tryptophan and eventually the serotonergic system have an impact on behaviours related to anxiety, stress, fear, and aggression (1215). Trp does, however, compete for transport through the blood-brain barrier with other large neutral amino acids (LNAAs), such as tyrosine, phenylalanine, leucine, isoleucine, and valine. Trp has the lowest content of any LNAA in the majority of protein-containing meals, in contrast to its estimated dietary requirement (11,16). Therefore, in most situations, increasing the protein content of a meal effectively lowers the Trp: LNAA ratio and reduces the likelihood that Trp will penetrate the blood-brain barrier. Since high-protein dog meals are currently popular, further research is required to determine how consuming Trp, which boosts serotonergic brain activity, affects dogs’ mood and behaviour. Currently, such research is restricted to studying the results of dietary Trp supplementation in individuals who are prone to or have already been diagnosed with behavioural problems including aggression, hyperactivity, or anxiety (12,15,17).
The aim of this study was to examine and assess behavioural changes in adult mixed-breed hounds that were in good health, well-adjusted, and fed a nutritionally complete and balanced diet over a 24-week period that contained graded concentrations of tryptophan (0.05% (05Trp), 0.1% (10Trp), and 0.15% (15Trp). The dogs’ behavioural responses to either a familiar approaching individual (FAI) or an unfamiliar approaching individual (UAI) were observed and recorded. The improvement would be greatest in the UAI groups and between the control diet and the 15Trp diet, according to our hypothesis. Supplementing diets with Trp would improve some, but not all, canine behavioural scores. This study was created as an outgrowth of a wider experiment looking into the use of dried chicken protein instead of soybean meal in a balanced and nutritionally complete dried adult dog food (18).
L-tryptophan overdose in dogs is possible.
Pets will likely be left at home for longer periods of time than they may be accustomed to as offices gradually reopen and humans resume their previous working conditions. Since many of us have stayed by our pets’ sides over the past year, they could become anxious when we have to leave them for extended periods of time. Some individuals use calming remedies and treats for their pets to help them cope with the stress this can cause for our beloved friends. These kinds of goodies should be secure when used as directed on the box, but what happens if your pet consumes the contents of the container while you’re away?
- Dogs frequently receive melatonin as a soothing or sleep aid, and it is occasionally prescribed as a treatment for a particular skin condition. Primary symptoms of an accidental overdose include nausea, drowsiness, and lethargy. Infrequently, incoordination may happen. Fortunately, even in overdoses, melatonin side effects are not anticipated to be severe. If your pet does become uncoordinated, you should keep them in a cage to prevent them from hurting themselves.
- Another component that is frequently seen in calming agents is tryptophan. In the form of chews, tablets, capsules, and powders, tryptophan is used to enhance serenity in canines and felines. Egg whites, cheese, fish, soybeans, and pumpkin seeds all naturally contain it. Your pet may exhibit moderate digestive symptoms (vomiting or diarrhoea) and lethargy in a tryptophan overdose condition.
- More and more chews, snacks, and soothing aids contain hemp and cannabidiol (CBD). An overdose of these medicines may result in nausea, vomiting, diarrhoea, cramping, depression, drowsiness, lethargy, and occasionally urine incontinence. If present, these symptoms could linger for 24 to 72 hours. In order to prevent injury, your pet should be kept inside if they have trouble with their balance. Take your pet to a veterinary facility right soon for treatment and supportive care if they are unable to sit up or are not rousable.
- People frequently use valerian root as a sedative or sleep aid. It is also utilised in many calming treats for pets to lessen nervousness. Valarian root overdoses may result in drowsiness, unsteadiness, lowered body temperature, and vomiting. Agitation may be a hazard with big exposures.
- The sodium levels in the blood can vary if excessive amounts of calming or sleep chews are consumed by our pets, yet they are easier to encourage them to eat. Increased thirst or more severe nervous system symptoms including agitation, tremors, and even seizures may occur if salt levels are too high. It could be fatal if not addressed in the early stages.
Always consult your veterinarian before introducing any vitamins, aids, or supplements into your pet’s regimen in order to protect your pet and avoid any unintentional overdoses. Additionally, you should keep any therapeutic chews, treats, or aids securely locked inside of a cabinet that is out of your pet’s reach.
What negative impacts does tryptophan have?
When ingested orally, L-tryptophan is a dietary component that is found naturally in a variety of foods. Supplemental L-tryptophan may be safe to consume for up to three weeks. The adverse effects of L-tryptophan include sleepiness, nausea, vomiting, diarrhoea, headaches, blurred vision, and others.
L-tryptophan was connected to occurrences of eosinophilia-myalgia syndrome, a neurological disease, in 1989. (EMS). However, contamination might be the cause of these situations. A single factory in Japan produces L-tryptophan, which has been linked to over 95% of all EMS cases.
There isn’t enough trustworthy data to determine whether taking L-tryptophan for longer than three weeks is safe.
Does tryptophan cause fatigue in dogs?
There is some evidence that eating a tryptophan-rich meal can have soothing benefits, even if feeding a turkey dinner has not yet been shown to be beneficial in the management of behavioural issues in cats and dogs.
Are dogs affected by the tryptophan in turkey?
My grandmother was a character out of a novel “My sister and I refer her Nana. Nana was an excellent cook who frequently showed her affection by preparing scrumptious meals and comfort foods. Thanksgiving, the most celebrated food festival in America, was unquestionably the event to attend at her house. My family, like many Americans, gobbled up everything Nana put on her crowded dining room table that day, including mashed potatoes, stuffing, butternut squash, toasty buns, salads, corn casserole, and, Thanksgiving course, the required roasted turkey. My sister and I used to overindulge at this annual feast and then go into food induced comas, sleeping off the excess for many hours before waking up to consume one more piece of pie.
Years later, I discovered that the tryptophan amino acid, a specific ingredient in turkey, was probably to blame for my post-meal sleepiness. An initial proponent of this hypothesis claimed that turkey flesh has abnormally high quantities of tryptophan.
Tryptophan is taken and utilised by the body to make the neurotransmitters serotonin and melatonin (a hormone). Melatonin aids in promoting sensations of sleepiness (i.e., improves sleep), whereas serotonin’s neural pathway provides relaxing and anti-anxiety properties. According to the hypothesis, the body produces more melatonin and serotonin after eating a high-protein meal, especially one that is high in tryptophan, which results in sleepiness, decreased anxiety, and a peaceful frame of mind. The post-turkey coma has here!
Early in the 1980s, the tryptophan/turkey idea gained so much traction and acceptance that nutrient-supplement businesses made the decision to completely ignore the turkey component of the equation and start creating and marketing tryptophan supplements instead (L-tryptophan). These were initially marketed as sleep aids and ways to lessen anxiety symptoms. The advertised advantages of L-tryptophan, however, quickly grew to include, among other things, claims that it would improve athletic performance, alleviate facial pain, prevent premenstrual syndrome, and improve attention in children with attention deficit-hyperactivity disorder. But this is how these things work. (The marketing of L-tryptophan as a therapy for Tourette syndrome is my particular favourite.)
L-tryptophan had a solid reputation as the essential amino acid for “everything that ails you’ until 1989, when it was discovered to be the cause of eosinophilia-myalgia in more than 5,000 people, resulting in at least 37 fatalities and hundreds of lifelong disabilities. Its import and sale as a supplement were swiftly outlawed by the US Food and Drug Administration. The prohibition was in place until 2009, even though the issue was ultimately identified as a contaminant in a supplement purchased from a Japanese supplier (rather than the L-tryptophan itself). Although L-tryptophan is once again offered as a nutrient supplement, it has never again attained the kind of popularity it formerly enjoyed as a supplement for people.
Tryptophan and Dogs
It’s surprising that L-tryptophan was mostly overlooked by the dog community until a study found that providing supplementary L-tryptophan to dogs may lessen aggressiveness motivated by dominance or territoriality1 in 2000. (see references on page 10). The researchers also looked at hyperactive and excitable dogs, but they were unable to detect any effects of L-tryptophan on either of these characteristics. However, the research gave rise to the misconception that tryptophan supplementation was helpful in calming dogs down and lessening issue aggression, both of which were not supported by the study.
There are many L-tryptophan products on the market now that claim to relax and reduce anxiety in dogs. It’s interesting to note that none of these products include only L-tryptophan; instead, they all also contain ingredients like chamomile flower, passion flower, valerian root, or ginger, all of which are said to have a calming effect on dogs.
So what does science have to say? Does consuming turkey or ingesting L-tryptophan supplements help people feel calmer and less anxious? Can it be used as a useful nutrient supplement to help dogs with behavioural behaviours brought on by anxiety?
The Turkey Sleepiness Myth
The idea that eating turkey makes you sleepy or calms you down is a myth. The theory falls short in a number of ways. First off, tryptophan content in turkey meat is not particularly high. It has about the same amount of tryptophan as other meats, but only about half as much as some proteins derived from plants, including soy. Do you fall asleep after eating a lot of tofu?
Second, studies have demonstrated that the tryptophan intake following a typical high-protein meal, even one with a lot of tryptophan, is not nearly high enough to significantly alter serotonin levels in the blood or in the synapses of neurons, where it counts the most.
Third, tryptophan that is transported in the bloodstream after eating needs to cross the blood-brain barrier and reach the brain in order to be transformed into serotonin (and subsequently into melatonin). Only a specific number of each type of amino acid may pass through this barrier, making it very selective. Due to its size, tryptophan must outcompete numerous other amino acids of a similar kind in order to pass the barrier. Tryptophan levels do rise after eating, especially if the meal contains a lot of protein, and it starts to pound on the blood-barrier door for admission. Although turkey has all of them, other amino acids that are also present in significant concentrations are also in competition with it. Because of this, relatively little tryptophan is converted in the brain after a meal that contains several other nutrients.
So why are you feeling so sleepy? It’s more likely that eating too much (which reduces blood flow and oxygen to the brain as your body diverts resources to the mighty job of digestion), drinking a little holiday (alcoholic) cheer, and possibly consuming a lot of high-carbohydrate foods like potatoes, yams, and breads—which leads to a relatively wider flu—are the real causes of the drowsiness and euphoria that we all experience after a great turkey dinner at Nana’ Whatever the reason, don’t give the turkey or the tryptophan the benefit of the doubt.
Tryptophan: Flying Solo
That being said, the incorrect emphasis on turkey did have some advantages in that it prompted researchers to examine tryptophan’s possible effects on emotions and behaviour when taken as a supplement. Tryptophan (and its metabolite 5-hydroxytryptophan, or 5-HTP) is a precursor to serotonin and has been investigated as a replacement or adjunct therapy for serotonin reuptake inhibitors (SRRIs), drugs that are frequently prescribed to treat depression in humans and are occasionally prescribed to treat anxiety-related behaviours in dogs.
Even though there hasn’t been much research on the effects of tryptophan supplementation in dogs, the initial dog study from 2000 was followed by a number of insightful papers:
Tryptophan and Anxiety
A sample of 138 privately owned dogs with anxiety-related behavioural issues was investigated by researchers at Wageningen University in the Netherlands2.
Design of the study: Half the dogs were fed a regular dog food (control), and the other half were given the same chow that had been made with added L-tryptophan. The designated groups for the dogs were unknown to both the owners and the researchers. In other words, this was a “double-blind, placebo-controlled study,” which is the “gold standard of research designs” (for more information on studies, check my book Dog Food Logic). For eight weeks, owners fed their dogs the prescribed food and noted any behavioural changes they saw. In order to evaluate the dogs at the conclusion of the trial, the researchers also carried out a series of behavioural tests.
Results: Although the supplemented dogs’ blood levels of tryptophan increased significantly (by 37%), neither the owners nor the researchers saw any behavioural differences between the supplemented dogs and the control dogs. All of the dogs’ behaviour did mildly change over time, but this shift was attributable to a placebo effect (more on placebos in the column next month). Overall, treatment with L-tryptophan did not appear to have any calming effects on the study dogs.
Tryptophan and Abnormal/Repetitive Behaviors
A group of 29 canines was found to exhibit a variety of abnormal-repetitive behaviours, including circling, anxiety-related lick granulomas, light chasing/shadow staring, and faeces eating. (Note: One can dispute the inclusion of stool-eating in this study, as many veterinary specialists believe that eating faeces is a widespread and typical kind of scavenging behaviour in domestic dogs.)
Another double-blind, placebo-controlled study was used for this one. Additionally, the study’s authors employed a “cross-over design” in which half the dogs were initially given the control diet while the other half were initially provided the test food for a length of time, followed by a second study period during which all the pups were shifted to the alternate diet. When a researcher only has a few volunteers, this widely used study design is beneficial since it helps to control for the placebo effect.
The dogs received treatment for intervals of two weeks, and daily frequency counts of their anomalous behaviours were kept.
Results: Supplemental L-tryptophan had no impact on the frequency or severity of abnormal/repetitive behaviours, according to the researchers. While the dogs were receiving the additional tryptophan and while they were consuming the control food, the owners noticed gradual improvements over time, despite this (there is the insidious placebo effect again).
This study’s limitations included its short duration and focus on unusual behavioural issues that are well known for being difficult to treat. However, this study did not offer any proof to back up the use of tryptophan supplementation for canine repetitive behaviour issues. Sorry, there isn’t a straightforward solution with L-tryptophan for those of you who live with poop-eating pets.
Tryptophan-Enhanced Diet and Anxiety
The same meal was either offered to dogs with anxiety-related behavioural issues as a control, or it was supplemented with L-tryptophan and alpha-casozepine, a little peptide derived from milk protein4.
This single-blind, crossover trial only included dog owners who were unaware of the treatments. Following an initial eight-week period on the control diet, all of the dogs were then moved to the test food for an additional eight weeks. It is impossible to discern between a placebo effect and a real diet effect in this study because the treatment group always adhered to the same protocol as the control group in this study design. (Note: The authors of the study only briefly highlight this significant issue in the research design.)
Results: For four of the five identified anxiety disorders, there was a slight decrease in the behaviours associated with anxiety as measured by the owners. While the change in score was statistically significant, the original severity of the difficulties was judged in each case as being relatively low (1 to 1.5 on a five-point scale where a score of 0 denoted the absence of the problem and a score of 5 denoted its utmost severity). This is not unexpected given the narrow margin between a score of 1 and a score of 0. Finally, since casozepine and L-tryptophan were added to the diet, specific conclusions about casozepine cannot be drawn.