What is it?
- TRP channels are a group of ion channels located on the plasma membrane of numerous cell types which are mediators of a variety of sensations, including pain, temperature, taste, pressure and stretch. Some of these channels are activated by compounds naturally found in food.
- TRP channel agonists taken as supplements, are a range of products, typically in liquid form, that are designed to prevent or reduce the severity of Exercise Associated Muscle Cramping (EAMC) during or after exercise. Commercial products that provide one or multiple TRP channel agonists as ingredients include pickle juice, and a commercial ‘shot’ that combines lime juice, capsaicin, ginger and cinnamon.
- The active ingredients are food components, that when ingested can activate TRP vanilloid 1 (TRPV1) and TRP Ankyrin 1 (TRPA1) channels in the mouth and upper gastrointestinal tract.1 These channels are involved in the differentiation of sensory aspects of food (i.e. salty taste and pungency) and can be activated by compounds in food that have these specific properties.3 TRPV1 can be activated by capsaicin, the compound in chillies that give them the spicy flavour (especially in an acidic environment), while TRPA1 is activated by components found in wasabi, mustard or horseradish, garlic, cinnamon, and to a lesser extent onion, garlic, cumin, anise and acidic foods.2,3
- Activation of TRPV1 and TRPA1 channels is suggested to alter neurological activity, and through the triggering of sensory neurons may reduce the excitability of α-motor neurons in the spinal cord, which influence skeletal muscle contraction.1 This in turn is theorised to increase the neurological threshold for muscle cramping or reduce the frequency or severity of muscle cramps during exercise.