You probably get your eyes tested to protect your sight, maybe have a yearly hearing test to check your ears—but, protecting your nose... eh? Recent research has discovered more than 600 genes in the human body associated with the sense of smell and that it's actually important to the human body.
Smell can help keep us alive by warning us of dangers such as food that might make us sick or the threat of fire, and it does this within only 100-150 milliseconds of breathing. "Smell also helps create the flavour of food and plays a role in controlling the variety of our diet and the nutrients we consume," says Jeanne Hort, a professor at News Zealand's Massey University.
In fact, each of us has a unique sense of smell and the strength of our unique smell is related to the genes you inherit (遗传) from your parents which determine which smell receptors (感受器) are expressed in the nose. Other factors further determine how sensitive your sense of smell is. Women generally have a stronger sense of smell than men, while damage from air pollution means people who live in highly polluted cities have a less sensitive sense of smell than those in rural areas. "We also know the sense of smell declines with age," says Professor Hort. "And if you've damaged your nose through head injury, illness or breathing in something that causes pain and discomfort, your sense of smell can also be negatively affected."
Protecting your nose from such damage is therefore the first step in activating your sense of smell. Avoid breathing in strong scents like chemicals. Then, keep your nose busy. For example, sniff (唉) vegetables and fruit as part of determining ripeness before you buy them and sniff more different smells exposed to your nose. "The sense of smell is a bit like a muscle, you can train it to become stronger by exercising it," says sensory expert Eugeni Roura.
