Read more: “Immune retune: Recharging your body’s natural defences“
How much shut-eye did you get last night? Even a moderate lack of sleep can put you at greater risk of catching a bug. In a seminal study, the sleeping habits of 153 healthy adults were recorded before they were given a sniff of a cold virus. It turned out that people who slept for less than 7 hours a night were almost three times as likely to catch a cold as the rest of the group (). It suggests people should make sure they are well rested before getting vaccinated, says Mark Opp, a neurobiologist at the University of Washington.
Opp recommends at least 8 hours and 20 minutes a night. That sounds a lot, but he reckons it is what everybody would get if left to their own devices. “If you take healthy subjects and let them sleep as long as they like, they sleep a little more each night, until it levels off at this duration,” he says.
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Sleep quality is also important, and that means making sure you are snoozing in a cool, dark and quiet place, says Opp. Living near a noisy place such as a train station is no good, even if you think you are used to the clatter. “People will say they’re accustomed to the noise, but studies show that their sleep has been disturbed,” says Opp. “If I put electrodes on their head, the brain activity would change to an awake pattern every time a train went by.”