|Image 1: Beta alanine and taurine;|
the former interferes with uptake
and reactions that involve the latter.
Like a partial agonist, beta alanine also interferes with the actions of taurine by inhibiting reactions that involve the former, so that the cardiomyocytes Jong and his colleagues from the Universities of South Alabama, USA, and Kobe, Japan, incubated with 5mM beta alanine for 48h induced a 45% decrease in taurine content in the neonatal rat cardiomyocytes. The sudden lack of taurine "enhanced superoxide generation, the inactivation of the oxidant sensitive enzyme, aconitase, and the oxidation of glutathione" (Jong. 2011), or, put simply, induced mitochondrial oxidative stress.
Associated with the increase in oxidative stress was a decline in electron transport activity, with the activities of respiratory chain complexes I and III declining 50–65% and oxygen consumption falling 30%.The decline in the activity of ND5 and ND6 respiratory chain complex subunits produced a "bottleneck" effect. Its almost as if you were trying to breath through a mask with two automated, taurine-powered openings. If you run out of "fuel", the valves in the openings won't open completely, you will gasping for air and (I bet) will become severely stressed.
|Figure 1: Oxygen consumption [in % of baseline] in control and in cardiomyocytes incubated with 5mM beta alanine.|
(data adapted from Jong. 2011)
As I have emphasized before, observations like these should make you reconsider the usefulness of isolated nutrient supplementation. Our understanding of the complex regulatory mechanisms and interaction that are taking place in our bodies are still very limited. Especially long term (or high dose) effects of many "supplements" (including amino acids, vitamins, fatty acids, herbs, etc.) have not been thoroughly investigated for many of the commercially available and, as it is the case with beta alanine, scientifically backed ergogenics, nootropics, fat burners etc. Oftentimes, looking at the nutrient-complex nature has wisely attached to what we ignorantly isolated and put into a tablet or powder, would suffice to know that, an amino acid like beta alanine, which occurs naturally in relatively low doses in slowly absorbed whole foods, mostly meat products, which obviously also contain taurine, was probably not meant to be ingested at high doses in isolated powder form. Co-ingestion (not necessarily at the same time) of adequate amounts of taurine or its precursors, methionine, respectively cysteine, would thus be the imperative prerequisite to benefit from the proven ergogenic effects (esp. during high-intensity exercise) of beta alanine.