How lifestyle and environment can influence pain sensitivity

Researchers have discovered that sensitivity to pain could be altered by a person's lifestyle and environment throughout their lifetime.

The study reveals that pain sensitivity, previously thought to be relatively inflexible, can change as a result of genes being switched on or off by lifestyle and environmental factors - a process called epigenetics, which chemically alters the expression of genes.

To identify levels of sensitivity to pain, scientists tested 25 pairs of identical twins using a heat probe on the arm. Participants were asked to press a button when the heat became painful for them, which allowed the researchers to determine their pain thresholds.

Using DNA sequencing, the researchers examined over five million epigenetic marks across the whole genome and compared them with a further 50 unrelated individuals to confirm their results.

The research team found wide variations between people and identified chemical modifications within nine genes involved in pain sensitivity that were different in one twin but not in her identical sister.

The chemical changes were most significant within a known pain sensitivity gene, TRPA1, already a therapeutic target in the development of painkillers (analgesics).

Lead author of the study, Dr Jordana Bell, Department of Twin Research and Genetic Epidemiology at King's College London, said that the potential to epigenetically regulate the behaviour of TRPA1 and other genes involved in pain sensitivity is very exciting and could lead to a more effective pain relief treatment for patients suffering with chronic pain.

The study has been published in journal Nature Communications.