Allergic reactions to peanuts are worse for adults if they’ve had a bad night’s sleep, research has found.
The national study also explored whether exercise affected the severity of the reaction, but found no significant effect.
Prof Graham Roberts from the NIHR Southampton Biomedical Research Centre supported the project as chair of the study steering committee.
Findings are being used by the Food Standards Agency to assess what level of peanut is safe for people with allergies in the UK.
The team’s results are published in The Journal of Allergy and Clinical Immunology.
How does lifestyle affect allergies?
Allergic reactions are known to vary depending on what the person has been doing before being exposed to the allergen.
This introduces a level of uncertainty that makes allergies difficult to manage, both from the patient’s perspective and the doctor advising them.
Yet there is little research showing what lifestyle factors have the strongest influence on allergic reactions, so patients and doctors don’t know what to look out for.
In this study, the researchers investigated the effects of exercise and lack of sleep on peanut allergy.
Three peanut ‘challenges’
Over 100 participants with a peanut allergy took part, including some with a severe peanut allergy.
They were split into three groups. All groups were given a dose of peanut flour in a dessert three times - this is known as an allergy ‘challenge’.
One time they were only allowed two hours of sleep the night before, another time they did intense exercise immediately afterwards, and another they did neither of these. The three groups did all of these, but each group did them in a different order.
The researchers gave each allergic reaction a severity score, and found they were worse after the poor night’s sleep. They also found the severity increased as participants had more doses of peanut.
How will these results be used?
The UK Food Standards Agency (FSA) have to decide what is deemed a ‘safe’ level of peanut contamination for people with peanut allergy. They funded this study to help inform their decision making.
Although sleep deprived people had a worse reaction, they only started to react at a very slightly lower level of peanut protein. This means the FSA does not need to lower their safe level any further to account for sleep deprivation.
Prof Graham Roberts, Professor of Paediatric Allergy and Respiratory Medicine at the University of Southampton, said:
“The minimal change in the amount of peanut protein causing an allergic reaction after being sleep deprived is reassuring for consumers with peanut allergy and the food industry.
“It means that food manufactures do not have to minimise potential peanut protein contamination even further to prevent allergic reactions in the presence of cofactors like sleep deprivation.”