The human body gets nutrients primarily through diet, while certain vitamins, like Vitamin D, are absorbed from sunlight. But can air also be a source of human nutrition?
Although much is still not known about the nutrients in the air, a recent study investigated deeper into the concept of "aeronutrients" and the mechanisms by which they are absorbed for human health.
Humans breathe in about 9,000 liters of air daily, which adds up to approximately 438 million liters over a lifetime. Given this, the components of the air we breathe can impact long-term health.
While much of the research has concentrated on the harmful effects of air pollution, the air around us may not only carry pollutants but also vital nutrients, such as vitamins, fatty acids, and minerals, that could support our health.
An earlier study in the 1960s showed how iodine in the air gets absorbed into the body. Researchers discovered that laundry workers exposed to airborne iodine had higher levels of the mineral in their blood and urine but the study did not specify the pathway through which it entered the body.
Evidence has also shown that welders exposed to higher levels of Manganese in the air have harmful levels of manganese buildup. A recent study in Ireland found that children living near coastal areas with high levels of seaweed had significantly higher iodine levels in their urine compared to those from coastal areas with less seaweed or rural areas, despite no changes in their iodine intake through diet.
In the latest study published in the journal Advances in Nutrition, researchers coined the term 'aeronutrients' to describe the beneficial nutrients in the air. These airborne nutrients include vitamins, fatty acids, and minerals, which the study proposes are absorbed through two main pathways: the respiratory system and the olfactory pathways.
The study also explored the role of airborne bacteria, called 'aeromicrobes,' which may help maintain the diversity of microbiota in the respiratory and gastrointestinal tracts.
The researchers believe both these concepts have significant implications for urban dwellers and those with limited access to nature, such as astronauts who spend extended periods in highly filtered air that may lack aeronutrients and aeromicrobes.
"The possibility that fresh air contributes to human nutrition and health may stimulate a re-evaluation of guidelines pertaining to nutrition and access to natural environments and will open new avenues of scientific enquiry," the researchers wrote in the study.