I’ve just had a look at the Equitop Myoplast site and here is a direct quote…..
“Scientific studies agree Spirulina supports healthy lean muscles, which means that feeding your horse a high-quality source of Spirulina offers you the reassurance that you are supporting your horse’s muscle development.” LINK
There are three studies mentioned to support this statement:
1) Voltarelli FA et al (2011). Int J Nutr & Met 3(3) 22-30
2) Voltarelli FA & de Mello MA (2008). Eur J Nutr 47: 393-400
3) Lu H et al (2006). Eur J Appl Physiol 98: 220-226
They don’t give the full references, which probably isn’t surprising when you dig deeper and find 2 of these studies are in rats and one is in people. NONE in horses.
So here is a breakdown of each study….
Voltarelli FA et al (2011). Int J Nutr & Met 3(3) 22-30 https://academicjournals.org/…/article…/79D4B444767
RATS fed a diet of which 17% was Spirulina. Spirulina was not different to a 17% Casein (milk protein diet) in rates of protein synthesis or breakdown.
Voltarelli FA & de Mello MA (2008). Eur J Nutr 47: 393-400 https://pubmed.ncbi.nlm.nih.gov/18807105/
RATS fed a diet that was 17% Spirulina or 17% Casein (milk protein). Protein synthesis was 44% higher in the Spirulina group, but protein breakdown was also 11% higher in the Spirulina group.
Lu H et al (2006). Eur J Appl Physiol 98: 220-226 https://pubmed.ncbi.nlm.nih.gov/16944194/
HUMAN subjects. 7.5g Spirulina per day for 3 weeks. Suggests in maximal exercise lasting around 12 min, there may be a small improvement in performance but with higher lactic acid. No effect on muscle damage. Muscle synthesis was NOT measured in this study. The experimental design is poor – two groups of 8 and no cross-over.
The amount of Spirulina fed in the rat studies was 17g/100g of the TOTAL diet. So imagine your horse eats 10kg hay and 3 kg hard feed a day, then YOU WOULD NEED TO FEED 2.2KG OF SPIRULINA A DAY to a 500kg horse to get the small effects seen in those studies. I wonder how many tubs of Equitop Myoplast work out at? The human study would be the equivalent of ~50g Spirulina. From the previous label information, I believe 50g of Equitop Myoplast supplies 20g Spirulina, so you would need to feed 125g Equitop Myoplast a day to replicate what was fed in the human study. EXCEPT, the human study didn’t show muscle development or protection of muscle.
Bottom line – still no evidence to support using Spirulina as a muscle builder or for muscle protection or support in horses!
If you want to know the truth about muscle-building supplements for horses, I’ve reviewed it here:
- Article – The science behind equine muscle building supplements by Dr David Marlin
- Webinar – The Secrets of Equine Muscle Building by Dr David Marlin
- Muscle building poll – see the results!
- Podcast – Building muscle in horses by Dr Gillian Tabor