Smells and aromas can move us in deeply personal ways, writes Emma Young.
Whenever she travels, Pam Dalton packs a scent. “If I’m in an anonymous hotel room, I want to smell something familiar, so I can close my eyes and have that scent around me, relaxing me, because it reminds me of home. I usually take a small dropper. I use a certain kind of rose oil that I particularly like.”
As a rule, it’s a lot easier to make people feel bad using odours than feel good, adds Dalton, who researches smell at the Monell Chemical Senses Center in Philadelphia. Part of that is just to do with the general nature of things, she says: “Things that are bad are always more intensely bad than good things are good.”
While there are universal malodours – scents that people from different parts of the world all agree are unpleasant – research has generally failed to find scents that make all of us feel happier, or calmer, or more relaxed. “But that doesn’t mean every one of us doesn’t have something in the olfactory world that might make us very, very happy or feel really good – it’s just that it’s really difficult to generalise the positive ones to large groups of people,” Dalton says.
In some studies, people exposed to the scent vanillin report a boost to their mood. There may be an innate reason. “Vanillin is in other things beside flowers. It can be in fruit – so perhaps there’s some pressure to be attracted to it,” says Dalton. But positive memories may play a bigger role. In the US and parts of Europe, at least, vanillin is a common ingredient in cakes and sweet treats.
Lavender is another scent often touted as having mood-improving properties. Is this well-accepted among scent researchers? “Not really,” Dalton says. “I’d venture to say that if there are physiological responses to certain extracts – botanicals, or whatever they are – they’re probably pretty small in comparison to the psychological response we have to it. So in this culture [the US], most people don’t really like essential lavender oil. It smells sort of disinfectant. Go to France, and it’s preferred.”
Her advice, if you want to use scent to improve your mood, is not to go for a fragrance or candle-making company’s claims of which combinations are most relaxing but to “find something you associate with something very positive – and that will be the one that has the most potent effects for you”.
But if you want to use scent to feel more energised, this should be more straightforward. Some foods and drinks contain compounds that stimulate the trigeminal nerve, which (among many other things) detects chemical irritants. Anything that has a ‘heating’ component (like chilli or horseradish) or a ‘cooling’ component (like various types of mint) can do this. Since these messages signal a potential threat, they boost alertness.
Quite how long that will last isn’t clear. A drug like caffeine, say, has a fairly long-lasting effect. “But just to energise you in the moment, I think having a sniff of something is a lot better, safer and quicker,” Dalton says.