Baths in spas, thalasso cures, nasal hygiene, drinking blisters: seawater has many health benefits. Studies remain rare but the sector wants to revive research.

1. The sea relieves rheumatism

True. It is even the oldest recognized virtue of sea bathing. In 1899, Dr. Louis Bagot opened the first thalassotherapy centre in Roscoff, Finistère. He invented the treatment of rheumatism in heated seawater, providing a muscle relaxant and “relaxing” effect. Immersed in seawater, we evolve in weightlessness with the thrust of Archimedes which divides by ten our body weight, which allows to mobilize the joints gently. Dr. Marie Perez Siscar, President of France Thalasso, has just published a study of 600 spa guests suffering from osteoarthritis. After three days, 60% say that their pathology has improved overall (less pain and regained functionality) and 33% have decreased their consumption of medications. After thirty days of treatment, these scores rise to 99% and 75% respectively.

2. Thalassotherapy is only for seniors

False. Historically, these centers have mostly been frequented by seniors because it takes time and money to benefit from them. But in recent years, the thalasso sector has been developing short stays for overworked workers. The cost remains high: around 100 euros for a day of care and 1,500 euros for a week (with accommodation). Unlike thermal cures, reimbursed at 65% in some indications, this type of treatment is no longer supported in France since 1998. “The Ministry of Health considered that thalassotherapy could survive the dereimbursement, while this was not the case for thermal baths, which supported many cities. From there, the focus was on well-being, more than on medical prevention,” explains Dr. Yves Tréguer, cardiologist and former president of the International Federation of Thalassotherapy Sea and Health. This shift partly explains why medical research remains limited in this sector.

3. By the sea, you feel less stressed

True. Many of us feel revitalized during a stay by the sea. According to a study published in 2012 by the University of Exeter (United Kingdom), people living less than five kilometers from the sea say they are healthier and less stressed than others. By crossing this subjective feeling with health data from 15,000 Britons (longevity, diseases, etc.), the researchers were able to verify this effect, which exceeds that provided by green spaces. The sea air plays a clear role – smokers cough less for example – as well as the vision of the blue immensity (associated with the sound of the waves, the calm …). But the health benefits come mainly from the diversity of physical activities practiced by the sea. A general practitioner in Biarritz (Pyrénées-Atlantiques) and author of DetoxSEAfication (Surf Prevention, 2018) – a book on scientifically based seawater treatments – Dr Guillaume Barucq has seen this relaxing effect among members of the Biarrot Polar Bears club. Among these bathers, who jump into the water every day, winter and summer, 78% say that the baths put them in a good mood, 55% that they give them energy and 46% that they soothe them.

4. Cold baths are bad for the heart

False. When entering cold water, vasoconstriction of the superficial vessels leads to a reflux of blood mass to the inside of the body and deep organs. When we go out and warm up, the blood return leads to an influx into the peripheral vessels. This stimulation is excellent for the arteries, heart and veins, especially in people with venous insufficiency (heavy legs). Several studies have also highlighted the effects of cold baths (14 ° C) on immune cells (leukocytes and lymphocytes).

5. Drinking sea water is bad

Not necessarily. Certainly, you must get used to the taste, but drinking small amounts of seawater (10 to 60 ml / day) would have virtues. The French biologist René Quinton had developed in the early twentieth century a serum bearing his name, composed of purified seawater. Initially in the form of injectable ampoules, it was reimbursed until 1982 for infant gastroenteritis and rickets. It is still in oral version in pharmacies. This natural remedy is back to the taste of the day, especially in Japan. Several teams work on seawater from the depths, drawn from more than 200 meters, rich in mineral salts (96000 mg / liter for magnesium for example against 1200 on the surface). Studies have shown effects on “bad” cholesterol (Journal of Medicinal Food, 2013), bad bacteria like Helicobacter pylori (2012) and even on the development of tumor cells in breast cancer (International Journal of Oncology, 2013).

6. It treats skin diseases

True and false. Because it contains trace elements and minerals (magnesium, calcium, potassium …) in high concentration, seawater has effective anti-inflammatory properties for people suffering from seborrheic dermatitis, psoriasis or eczema. Several studies have shown that treatments combining sun exposure and bathing in the Dead Sea can greatly reduce psoriasis for a period of at least three months. “Nevertheless, in case of psoriasis or eczema in flare-up (with wounds), it is not recommended to take sea baths in a natural environment (risk of superinfection if the quality of the water is not good). And it is preferable to temporarily avoid thalassotherapy treatments,” says Dr. Barucq.

7. It accelerates wound healing

True and false. Applying sterile seawater to a small wound has an antimicrobial action that helps with healing. On the other hand, bathing repeatedly in seawater may dig the wound. In addition, the cleanliness of seawater varies depending on the location, microbes can infect it. In case of stagnant water or after heavy rains, pollution can promote the presence of bacteria.

8. It clears the airways

True. A simple stay by the sea promotes the oxygenation of the blood by the lungs and allows a  wider and more effective breathing. As for seawater baths, they help prevent colds and other ENT problems. In case of a cold, seawater sprays decongest the nasal mucosa. A study published in April 2016 in the Cochrane Review shows that daily nasal irrigations with a large volume of saline (150 ml) decrease runny nose, while increasing the quality of life of people suffering from rhinosinusitis. Instillations with 10-15 ml give disappointing results.

9. It is an anti-fatigue solution

Probably. Many of us feel a muscular and psychological relaxation and find a better sleep by the sea. An effect difficult to demonstrate scientifically as fatigue is a subjective sensation with multifactorial causes. In 2017, the Roscoff center conducted a study with 120 curists: after a week of treatment, 22% said they were tired against 40% when they arrived. Good results, which were maintained three months later. Beyond the benefits of the treatments – real or not – the thalasso also represents a break involving rest and a healthy diet in a serene setting.

10. It is a reservoir of good bacteria

True. Researchers from Ifremer (French Research Institute for the Exploitation of the Sea) are dedicated to the search for good marine bacteria to fight against food poisoning. Thus, bacterial strains sprayed on  smoked salmon prevent the development of Listeria monocytogenes, which is responsible for listeriosis. Other researchers are working on the bacterium Alteromonas infernus, discovered near hydrothermal springs in the Pacific. “It produces complex sugars that have the property of regenerating tissues (skin, cartilage, bones) and limiting metastases,” says Ifremer. An ocean of discoveries to come!