Heat really is good for pain

The old wives’ tale that heat relieves pain may be rooted in science after all

Scientists have found a molecular basis for the long-standing theory that heat, such as that from a hot-water bottle applied to the skin, provides relief from internal pains, such as stomach aches, for up to an hour.

Dr Brian King, leader of the team that carried out the research at the UCL Department of Physiology, said: “The heat doesn’t just provide comfort and have a placebo effect – it actually deactivates the pain at a molecular level in much the same way as pharmaceutical painkillers work. We have discovered how this molecular process works.”

The team found that when heat over 40^oC is applied to the skin near to where internal pain is felt, it switches on heat receptors located at the site of injury. These heat receptors in turn block the effect of chemical messengers that cause pain to be detected by the body.

The team found that the heat receptor, known as TRPV1, can block the pain

Stomach ache? Try a hot water bottle instead of popping a pill

receptor P2X3. These pain receptors are activated by ATP, the body’s source of energy, when it is released from damaged and dying cells. By blocking the pain receptors, TRPV1 is able to stop the pain being sensed by the body.

Dr King added: “The problem with heat is that it can only provide temporary relief. The focus of future research will continue to be the discovery and development of pain relief drugs that will block P2X3 pain receptors. Our research adds to a body of work showing that P2X3 receptors are key to the development of drugs that will alleviate debilitating internal pain.”