For the first time, researchers have proven that living by the sea is better for people's health. A study demonstrated that sea air stimulates the human immune system and boosts disease resistance.
We often hear that living by the sea makes people healthier, but this has been hard to prove scientifically. Until now, the claim was mainly supported by the psycho-social aspect: people living by the sea often spend more time outdoors and therefore usually exercise more. Studies have also shown that people living within five kilometres of the sea are healthier and less stressed. Here again, the environment was seen to assist in positive behavioural patterns.
More substantial proof has now been gathered by researchers from the Flemish Institute for the Sea (VLIZ), UGent and UAntwerp, who looked into the power of seawater itself.
They found that regular exposure to sea air combats inflammation and protects the human body – the first time a study has proven this.
Bacteria in sea air
The researchers analysed the effect of marine bacteria and bioactive compounds – present in sea air – on human cell cultures. This was done by treating human cells in a lab with aerosols from splashing seawater (both caught on the breakwater in Oostende and produced aerosols in the lab).
The so-called "biogenic hypothesis" argues that regular exposure to bacteria, viruses, fungi and derived substances tempers "pernicious bodily reactions" such as inflammation, diabetes, and even cancer. "This suggests that regular exposure to sea air counteracts bodily responses such as inflammation," the researchers noted.
Seawater has a beneficial effect on immunity. Credit: Belga/ Dirk Waem
In other words, seawater strengthens the immune system through the bacteria that train and maintain our immune system, thus making it stronger – a phenomenon referred to as the immunological effect.
The dose of bacteria is too small to make people sick but is enough to trigger a response by the immune system. A similar effect has been recorded in children who grow up on a farm or spend time outdoors. Being exposed to more bacteria increases immunity.
No miracle cure
Researchers added that the sea is full of microscopic organisms and that wave action creates droplets of 0.1-10 micrometres (marine aerosols). These droplets can remain airborne for a long time, travel long distances and are inhaled by people along the coast.
The benefits of marine aerosols for immunity could explain why people on the Italian coast were more resistant to Covid-19 than compatriots further inland.
The researchers stressed that people should not expect medical miracles from the sea – it cannot cure cancer, for example. But it could to some extent prevent lung cancer. The full study was published in 'Science of The Total Environment'.
