Take a deep breath

A few years ago a British tabloid newspaper ran a story about a couple claiming to be  “breatharians”, who maintained that they barely needed food and water to thrive but derived their sustenance from sunlight, air and the energy of the universe. The very thought was understandably greeted by ridicule. Needless to say, we cannot live primarily on air and sunlight, as sadly demonstrated by a small number of practitioners who died trying.

But, maybe weirdly, there does now seem to be more to the concept than originally assumed, and according to scientists in Australia and the UK we can and do indeed absorb nutrients from the air we breathe, although of course nowhere near enough to live on.

The 7,000 to 8,000 litres of air we breathe each day mainly consists of oxygen, nitrogen, water vapour and argon. The oxygen is extracted by our lungs and duly replaced on exhalation by waste carbon dioxide.  But air can also contain trace amounts of compounds not normally regarded as airborne but that do have a nutritional value on ingestion. The first step in establishing the viability of aeronutrients was to identify the mechanism with which inhaled compounds could be absorbed by the body. The first port of call of inhaled air is of course the nasal cavity, where it is heated and humidified by tiny blood vessels. This is of course how snorted drugs of misuse such as cocaine enter the bloodstream en route to the brain.

The front-runners among the manifold candidates for micronutrients extracted from the air are currently iodine and vitamins such as vitamin D. Studies among three groups of people, some living near beaches with a lot of seaweed (a rich source of iodine gas), some near beaches with little of said seaweed and some residing inland showed that the first group had the highest levels of iodine in their bodies and the lowest incidence of iodine deficiency. Another highly promising candidate is all-trans retinoic acid, usually acquired by munching on carrots or consuming other foods containing beta-carotene. This acid is known to naturally occur in air-water interfaces such as at lakes and oceans and is essential for vital functions such as embryonic development and cellular regeneration. And with one in two people being deficient in vitamin D, even the idea of vitamin D inhalation is being mooted.

We are still largely at the dawn of the investigation of aeronutrients and what we may already be reaping from them, but the science is starting to concretise. The health benefits of spending time in nature have long been widely known and accepted but little understood -  aeronutrients could be one of the reasons.