In this post, my first on the Gene Food blog, I get into why I felt so good when I took the amino acid, L-tyrosine. I knew from digging into my genetics that I was somewhat prone to stress. I also knew that L-tyrosine affects dopamine levels. 1 To tie together what I thought was a connection, I asked Aaron, our head of research and lead geneticist, to help me with the research.
What is L-Tyrosine?
L-tyrosine is an amino acid that is a precursor to dopamine production. 2 Tyrosine is one of the many naturally-occurring, nonessential amino acids that can be derived from the essential amino acid phenylalanine, which is found in protein-rich foods. High tyrosine foods include meats, cheeses, and vegetables high in protein like kale and spinach.
L-Tyrosine and genetics
One of the best-cited benefits to supplementing with L-tyrosine is its ability to prevent a decline in cognitive performance, and the impact does seem to be affected by genetics.
The DDR2 gene
In a 2016 study, researchers identified that the snp rs6277 in the DDR2 (dopamine D2 receptor) gene demonstrated some interesting differences following l-tyrosine supplementation. 3 Previous studies have suggested that those carrying the risk allele ‘T’ may have reduced levels of dopamine in the striatum region of their brain, which is involved in multiple aspects of cognition. In the graph above you can see the relative score on a cognitive test for those carrying the ‘C’ allele and the risk ‘T’ allele. The black bars show those who just received a placebo and the grey bars show those taking l-tyrosine (2 g 1 hour before being tested) the lower the bar the better the performance. What first jumps out is that, in the placebo groups, there is little difference between the black bars (there is a slight increase for those with two copies (TT) but it is not significant). However, for those who took l-tyrosine the results are much different. Those carrying any number of copies of the ‘C’ allele did not show any effect from l-tyrosine supplementation. It was a different story for “TT” individuals who showed a large and significant improvement in their cognitive score one hour after taking L-tyrosine. The researchers don’t investigate it, but it would be interesting to see what effect sustained supplementation (probably at a lower dose) had on cognitive performance over time.
COMT and cognition
The next obvious gene of interest when discussing L-tyrosine is COMT. In a similar way to DDR2, COMT has been shown to regulate the levels of dopamine in the brain with the G472A (rs4680 ‘G’ is risk for cognition) and C186T (rs4633 ‘C’ is risk for cognition) SNPs being associated with impaired cognitive performance.4 It is therefore interesting that the association between COMT genotype and l-tyrosine hasn’t been investigated, especially as each SNP variant is relatively common. Researchers have hypothesized an effect, but no studies have been performed or reported.5
The next gene that’s worth discussing is MAOA. This is one of the more famous genes out there due to its nickname of “The Warrior Gene”. We’ve got a post explaining how this association is pretty tenuous. While the psychological effect of the various SNPs in MAOA may be oversold, their effect on dopamine and other neurotransmitter levels isn’t. Getting a handle on your MAOA type is quite tricky, but we detail it in the post I link to above. Back to l-tyrosine. Those with reduced MAO-A activity, which is marked by the 2, 3 and 5 R types may want to take care supplementing with l tyrosine. Their dopamine levels are already likely elevated, so making more may not necessarily be the best course of action. However, as above this is a hypothesized effect and there are no actual studies investigating any link.
Benefits of L-Tyrosine
Back to Taylor. I sometimes take 1,500 milligrams of l-tyrosine in the morning before eating breakfast. I’ve taken my dose both before and after meals, and have generally found that taking it before eating, shortly after waking up, produces the best effects. But how useful is it? For me personally, and your personal results may vary, l-tyrosine has become a go-to supplement that I’ll be keeping in my medicine cabinet for the foreseeable future. When you’re working in startups, distractions and interruptions are just an aspect of life that you learn to deal with – but that doesn’t make them any less stressful. That project you are neck deep in at the moment that’s due in an hour? Sure would be a shame to have a client call right about now to derail you. Oh, you’re working on an ad campaign? Wouldn’t it just be terrible if Facebook decided to refresh your page for some reason and cause you to lose all of the progress you’ve made? While these may seem minor and relatively insignificant on their own, this kind of constant-buzzing at the quantity it occurs is something that makes focusing pretty tricky during the day. Now, I don’t want to say that l-tyrosine was a miracle sort of cure-all, but I will say that I’ve noticed a distinct change in my reactions to these little micro-aggressors. My focus improved. Dropping what I’m doing to shift gears is an inconvenience, but not one that stresses me out anymore – I feel like I’m on my game, and switching around tasks to make sure everything gets done properly is just a brief intermission. My ability to focus feels refined, and I find it much easier to simply not stress about things that in the long run don’t matter as much as they may seem to at the time.
My verdict on l-tyrosine
Ultimately, I feel that this supplement helps me in two primary areas: Stress – Don’t sweat the small stuff has transformed from cliche motivational quip to something I find myself subconsciously practicing more often. If it’s not going to matter enough to be stressed out about a few days from now, it doesn’t matter enough to be stressed out about it now. Focus – Anybody that works on the computer for the majority (or entirety) of their day knows how temptation hides around every corner; all it takes is a simple popup from Facebook at the bottom of your screen to find yourself suddenly diving down a rabbit hole of funny pictures while your work sits in an adjacent browser tab. The temptation just doesn’t hit as hard anymore, and I find myself much more easily committing to a task and finishing it with the ability to tune nearly everything else out. While it may not be useful to everybody (as some of the studies have concluded), I’ve found that my genetic cocktail is made up of ingredients that make l-tyrosine a go-to supplement that I won’t be looking to abandon anytime soon.
When not to take L-tyrosine
While L-tyrosine increases dopamine, it also increases adrenaline and therefore should never be taken in the evening or before bed. According to the medical team at Mount Sinai Hospital, Tyrosine increases levels of thyroid hormone and is therefore contraindicated for people with hyperthyroidism or Graves disease. Also from Mount Sinai – people taking a class of antidepressants known as MAOI Inhibitors should avoid L-tyrosine supplements because, when combined with these antidepressants, tyrosine may raise blood pressure so high as to cause a stroke or heart attack.