Thalassotherapy, Health Benefits of Sea Water, Climate and Marine Environment: A Narrative Review

Abstract

The aim of this review was to summarize any evidence-based clinical uses of thalassotherapy. PubMed was searched up to the 15th July 2021 for relevant studies. Overall, 560 articles were found and 14 studies were included in this review. Clinical efficacy of thalassotherapy was mostly tested for skin problems (psoriasis, atopic dermatitis, vitiligo) and rheumatic disorders (fibromyalgia, ankylosing spondylitis). Disease severity and the patients’ quality of life significantly improved after intervention, with the majority of evidence for psoriasis and fibromyalgia. Thalassotherapy can be associated with symptomatic improvements in some health conditions. Further studies on the topic are recommended.

Full text

Environ. Sci. Proc. 2021, 3, x. https://doi.org/10.3390/xxxxx www.mdpi.com/journal/environsciproc
Proceedings
Thalassotherapy, Health Benefits of Sea Water, Climate and
Marine Environment: A Narrative Review †
Michele Antonelli 1,* and Davide Donelli 2
1 Department of Public Health, AUSL-IRCCS of Reggio Emilia, Via Giovanni Amendola 2, 42122 Reggio
Emilia, Italy; ORCID: 0000-0002-5941-6604
2 Department of Medicine and Surgery, University of Parma, 43121 Parma, Italy; davide.donelli@ausl.re.it;
ORCID: 0000-0002-7895-2840
* Correspondence: michele.antonelli@ausl.re.it
† Presented at the 6th International Electronic Conference on Water Sciences (ECWS-6), Online,
15–30 November 2021.
Abstract: The aim of this review was to summarize any evidence-based clinical uses of thalasso-
therapy. PubMed was searched up to the 15th July 2021 for relevant studies. Overall, 560 articles
were found and 14 studies were included in this review. Clinical efficacy of thalassotherapy was
mostly tested for skin problems (psoriasis, atopic dermatitis, vitiligo) and rheumatic disorders
(fibromyalgia, ankylosing spondylitis). Disease severity and the patients’ quality of life signifi-
cantly improved after intervention, with the majority of evidence for psoriasis and fibromyalgia.
Thalassotherapy can be associated with symptomatic improvements in some health conditions.
Further studies on the topic are recommended.
Keywords: environmental health; marine climate; medicine; review; sea water; thalassotherapy
1. Introduction
Seas cover 70% of our planet’s surface and have always been important since an-
cient times for many human activities (i.e., feeding habits, long travels, commercial ex-
changes, religion, arts, spirituality and healing rituals) (Figure 1) [1]. Therapeutic uses of
sea water date back to ancient Egypt and are characterized by a long-standing tradition
in many countries [2]. “Thalassotherapy”, a Greek-derived term originating from the
combination of “thalassa” (sea) and “therapy”, is still empirically recommended for pa-
tients with some skin, rheumatic or respiratory diseases [3]. Broadly speaking, thalasso-
therapy includes not only baths in sea or sea-like salty water, but also seaweed or sand
baths, sunlight exposure, inhalation of marine aerosol and, in general, any controlled in-
teraction with marine environments and their natural elements for health-promoting
purposes [4]. With rising attention over human-environment relationships and empirical
evidence from traditions, biomedical research has recently started to explore the role of
different natural settings for well-being improvement [5], including potential benefits
offered by coastal areas, their waters and climate.
The aim of this review was to briefly summarize evidence-based clinical uses of
thalassotherapy.
Citation: Antonelli, M.; Donelli, D.
Thalassotherapy, Health Benefits of
Sea Water, Climate and Marine Envi-
ronment: A Narrative Review. Envi-
ron. Sci. Proc. 2021.
Academic editor: Marcel J.F. Stive
Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations.
Copyright: © 2021 by the authors.
Submitted for possible open access
publication under the terms and con-
ditions of the Creative Commons At-
tribution (CC BY) license (https://cre-
ativecommons.org/licenses/by/4.0/).

Environ. Sci. Proc. 2021, 3, x FOR PEER REVIEW 2 of 4
Figure 1. Sea waves in Japanese art. Picture freely released by Karen Arnold under the “CC0 Pub-
lic Domain” licence. Available online at: https://www.publicdomainpictures.net/ (accessed on 20
July 2021).
2. Methods
This research was designed as a narrative review of the scientific literature. Pub-
Med was searched from inception up to the 15 July 2021 for clinical studies about the
efficacy of controlled exposure to marine or marine-like (i.e., salt lake) environments for
any health condition. The MeSH term “thalassotherapy” was used to retrieve relevant
articles and narrow down the search. The following PICOS criteria were chosen for in-
clusion and exclusion of research items:
• P (population): healthy subjects or patients with any disease diagnosed in accord-
ance with international guidelines.
• I (intervention): thalassotherapy, defined as any controlled interaction with marine
or marine-like environments and their natural elements for health-promoting pur-
poses.
• C (comparator): any type of comparison, including no control.
• O (outcomes): any measurable clinical improvement, including changes in symp-
tom scores and health-related quality of life.
• S (study design): any type of clinical study involving human subjects. In vitro and
in vivo laboratory experiments were excluded, as well as commentaries, technical
reports and literature reviews.
Articles were excluded when their full-text version was unavailable/irretrievable or
when they had no English summary. Studies published prior to 1980 were also excluded
for being too outdated. Retrieved evidence was summarized and critically discussed.
3. Results
Overall, 560 articles were found, but only 152 studies were published after 1980.
Research items matching the PICOS criteria were 14 [6–19]. Results of studies eligible for
inclusion were reported in Table 1. Clinical efficacy of thalassotherapy was tested for the
following health conditions:
• Skin problems, mostly psoriasis, but also atopic dermatitis and vitiligo.

Environ. Sci. Proc. 2021, 3, x FOR PEER REVIEW 3 of 4
• Rheumatic disorders, such as fibromyalgia and ankylosing spondylitis.
Thalassotherapy included a combination of sea water balneotherapy, climate ther-
apy, controlled sunlight exposure, physical exercises and rehabilitation programs. Ses-
sions were held in different locations, ranging from the Dead Sea (a salt lake) to the At-
lantic Ocean. Treatment duration was quite heterogeneous, but lasted 3 to 6 weeks on
average. Results indicated that thalassotherapy can significantly improve disease sever-
ity, symptoms and quality of life in different health conditions. Only 6 trials had a con-
trol group, whereas the other studies had an observational or a pre-post design.
Table 1. Summary of evidence from included studies.
Condi-
tion
Population
(n)
Interven-
tion type
Location
Control
type
Treatment
duration
Outcomes
Results
Study
design
Refer-
ence
Psoriasis
254 adults
C-BT
Atlantic
Ocean (Ca-
nary Is-
lands)
/
3 weeks
↓ disease
severity
Pre-test PASI:
8.6 [7.7–9.4]
Post-test PASI:
1.6 [1.2–2.1]
US
[7]
85 adults
C-BT
Dead Sea
/
>5 days
↓ disease
severity
Pre-test PASI:
17.5 ± 11.0
Post-test PASI:
4.4 ± 4.6
US
[10]
17 children
C-BT
Dead Sea
/
2 weeks
↓ disease
severity
35.3% of patients
showed excellent im-
provement, 29.4%
moderate improve-
ment, 35.3% poor re-
sponse
US
[8]
10 adults
C-BT
Dead Sea
/
4 weeks
↓ parakeratosis
↓ dermal immune cell infiltration
↑ enkephalin levels
US
[9]
18 adults
C-BT
Dead Sea
/
4 weeks
↓ disease
severity
Pre-test PASI:
14.8 ± 5.4
Post-test PASI:
1.8 ± 3.1
US
[19]
70 adults
C-BT
Dead Sea
/
>5 days
↓ disease
severity
Pre-test PASI:
16.6 ± 11.0
Post-test PASI:
4.0 ± 4.2
US
[6]
64 adults
C-BT
Dead Sea
/
4 weeks
↓ disease
severity
Pre-test PASI:
31.7 ± 13.3
Post-test PASI:
1.4 ± 1.9
US
[11]
Atopic
dermati-
tis
30 adults
BT with
Dead Sea
salts
/
Tap water
6 weeks
↓ TEWL
↓ skin in-
flammation
Post test difference
between groups
(TEWL):
−19%
RCT
[12]
116 chil-
dren
C-BT
Dead Sea
Steroid
drugs
4 weeks
↓ disease
severity
Post-test SCORAD
(int.):
87.5 ± 13.4%
Post-test SCORAD
(con.):
86.1 ± 11.3%
RCT
[13]

Environ. Sci. Proc. 2021, 3, x FOR PEER REVIEW 4 of 4
Vitiligo
436 adults
C-BT
Dead Sea
/
Variable
↑ skin pig-
mentation
3.9% of patients
showed total re-
pigmentation; 81.4%
good repigmentation
ORS
[14]
Ankylos-
ing
spondy-
litis
107 adults
RT
Mediterra-
nean Sea
(Turkey)
The same
program,
but in
Norway
4 weeks
↑ spinal
mobility
↓ symp-
toms
Pre-post test ASAS
(int.):
−3.7 ± 2.2
Pre-post test ASAS
(con.):
−1.7 ± 1.9
RCT
[15]
Fibrom-
yalgia
134 adults
C-BT +
usual care
Mediterra-
nean Sea
(Tunisia)
Usual care
2 and a
half weeks
↑ QoL
↓ pain
Post test QALYs-VAS
(int.):
0.23 ± 0.08
Post test QALYs-VAS
(con.):
0.19 ± 0.06
RCT
[17]
46 adults
C-BT + ex-
ercise
Atlantic
Ocean (Bra-
zil)
The same
program,
but in a
pool
12 weeks
↑ QoL
↓ pain
↑ mood
Pre-post test FIQ
(int.):
−40.6 ± 11.1
Pre-post test FIQ
(con.):
−38.7 ± 10.9
RCT
[18]
58 adults
C-BT + ex-
ercise
Mediterra-
nean Sea
(Tunisia)
Usual care
2 and a
half weeks
↑ QoL
↓ pain
↑ mood
Pre-post test FIQ
(int.):
−6.3 ± 11.4
Pre-post test FIQ
(con.):
−0.9 ± 10.2
RCT
[16]
Notes: ASAS: ASsessment in Ankylosing Spondylitis (improvement criteria); BPSS: Beer Sheva Psoriasis Severity Score;
BT: Balneotherapy; C-BT: Climato-Balneotherapy; Con.: Control; FIQ: Fibromyalgia Impact Questionnaire; Int.: Interven-
tion; ORS: Observational Retrospective Study; PASI: Psoriasis Area Severity Index; QALYs: Quality-Adjusted Life Years;
QoL: Quality of Life; RT: Rehabilitation Therapy (set in a thalassotherapy center); SCORAD: SCORing Atopic Dermatitis;
TEWL: Trans-Epidermal Water Loss. ↑: significant increase; ↓: significant decrease.
4. Discussion
There is evidence to support the notion that thalassotherapy can be beneficial to
improve several diseases, especially chronic inflammatory conditions and degenerative
illnesses. Mechanistic studies suggest that these benefits may be due to a combined ac-
tion of different natural components:
• Highly mineralized water immersion, associated with symptomatic improvements
in osteoarthritis, back pain of rheumatic origin, fibromyalgia, psoriasis, atopic der-
matitis, chronic venous insufficiency of lower limbs and other health problems [20].
• Marine climatic conditions, characterized by pleasing mild temperatures and sunny
weather [21].
• Controlled sunlight exposure, beneficial for patients with psoriasis and to boost the
body’s vitamin D supply [22].
• Interaction with biogenic compounds released in the environment by seaweed, al-
gae and coastal vegetation [23].
• Hot sand baths, possibly useful for some rheumatic diseases [24].
• Marine aerosol inhalation, with beneficial effects for some respiratory conditions
[25].

Environ. Sci. Proc. 2021, 3, x FOR PEER REVIEW 5 of 4
Health benefits of thalassotherapy may last for around 90 days after treatment, es-
pecially in patients with psoriasis [19]. Some concerns were expressed for long-term clin-
ical safety of this therapeutic practice, in particular for potentially higher incidence of
skin cancer due to excessive sunlight exposure. In this regard, it is essential to be medi-
cally checked before undergoing a cycle of thalassotherapy and to strictly follow profes-
sional recommendations in order to avoid high ultraviolet radiation exposure [26].
In conclusion, thalassotherapy can be associated with symptomatic improvements
in some health conditions. Further studies on the topic are recommended to better quan-
tify the effect size of intervention, as well as to assess long-term benefits, risks and any
moderators of the effect.
Author Contributions: Conceptualization, M.A.; Methodology, M.A. and D.D.; Validation, M.A.
and D.D.; Investigation, M.A. and D.D.; Resources, M.A. and D.D.; Data Curation, M.A. and D.D.;
Writing—Original Draft Preparation, M.A. and D.D.; Writing—Review & Editing, M.A. and D.D.;
Visualization, M.A. and D.D.; Supervision, M.A. and D.D.; Project Administration, M.A.
Funding: This research received no external funding.
Acknowledgments: None.
Conflicts of Interest: The authors declare no conflict of interest.
References
1. McNiven, I. J. Sentient Sea: Seascapes as Spiritscapes. Handbook of Landscape Archaeology; Routledge: England, UK, 2016; pp.
149–157, ISBN 9781315427737.
2. Lucchetta, M.C.; Monaco, G.; Valenzi, V.I.; Russo, M.V.; Campanella, J.; Nocchi, S.; Mennuni, G.; Fraioli, A. The historical-
scientific foundations of thalassotherapy: state of the art. Clin. Ter. 2007, 158, 533–541.
3. Munteanu, C.; Munteanu, D. Thalassotherapy Today. Balneo Res. J. 2019, 10, 440–444, doi:10.12680/balneo.2019.278.
4. Maraver, F.; Michán, A.; Morer, C.; Aguilera, L. Is Thalassotherapy Simply a Type of Climatotherapy? Int. J. Biometeorol. 2011,
55, 107–108.
5. Jimenez, M.P.; DeVille, N.V.; Elliott, E.G.; Schiff, J.E.; Wilt, G.E.; Hart, J.E.; James, P. Associations between Nature Exposure
and Health: A Review of the Evidence. Int. J. Environ. Res. Public Health 2021, 18, doi:10.3390/ijerph18094790.
6. Cohen, A.D.; Van-Dijk, D.; Naggan, L.; Vardy, D.A. Effectiveness of Climatotherapy at the Dead Sea for Psoriasis Vulgaris: A
Community-Oriented Study Introducing the “Beer Sheva Psoriasis Severity Score.” J. Dermatolog. Treat. 2005, 16, 308–313,
doi:10.1080/09546630500375841.
7. Wahl, A.K.; Langeland, E.; Larsen, M.H.; Robinson, H.S.; Osborne, R.H.; Krogstad, A.-L. Positive Changes in Self-Manage-
ment and Disease Severity Following Climate Therapy in People with Psoriasis. Acta Derm. Venereol. 2015, 95, 317–321,
doi:10.2340/00015555-1939.
8. Ben-Amitai, D.; David, M. Climatotherapy at the Dead Sea for Pediatric-Onset Psoriasis Vulgaris. Pediatr. Dermatol. 2009, 26,
103–104, doi:10.1111/j.1525-1470.2008.00837.x.
9. Nissen, J.B.; Avrach, W.W.; Hansen, E.S.; Stengaard-Pedersen, K.; Kragballe, K. Increased Levels of Enkephalin Following
Natural Sunlight (combined with Salt Water Bathing at the Dead Sea) and Ultraviolet A Irradiation. Br. J. Dermatol. 1998, 139,
1012–1019, doi:10.1046/j.1365-2133.1998.02557.x.
10. Cohen, A.D.; Shapiro, J.; Michael, D.; Hodak, E.; Van-Dijk, D.; Naggan, L.; Vardy, D.A. Outcome of “Short-Term” Dead Sea
Climatotherapy for Psoriasis. Acta Derm. Venereol. 2008, 88, 90–91, doi:10.2340/00015555-0340.
11. Harari, M.; Novack, L.; Barth, J.; David, M.; Friger, M.; Moses, S.W. The Percentage of Patients Achieving PASI 75 after 1
Month and Remission Time after Climatotherapy at the Dead Sea. Int. J. Dermatol. 2007, 46, 1087–1091, doi:10.1111/j.1365-
4632.2007.03278.x.
12. Proksch, E.; Nissen, H.-P.; Bremgartner, M.; Urquhart, C. Bathing in a Magnesium-Rich Dead Sea Salt Solution Improves Skin
Barrier Function, Enhances Skin Hydration, and Reduces Inflammation in Atopic Dry Skin. Int. J. Dermatol. 2005, 44, 151–157,
doi:10.1111/j.1365-4632.2005.02079.x.
13. Marsakova, A.; Kudish, A.; Gkalpakiotis, S.; Jahn, I.; Arenberger, P.; Harari, M. Dead Sea Climatotherapy versus Topical Ster-
oid Treatment for Atopic Dermatitis Children: Long-Term Follow-up Study. J. Dermatolog. Treat. 2020, 31, 711–715,
doi:10.1080/09546634.2019.1605138.
14. Czarnowicki, T.; Harari, M.; Ruzicka, T.; Ingber, A. Dead Sea Climatotherapy for Vitiligo: A Retrospective Study of 436 Pa-
tients. J. Eur. Acad. Dermatol. Venereol. 2011, 25, 959–963, doi:10.1111/j.1468-3083.2010.03903.x.
15. Staalesen Strumse, Y.A.; Nordvåg, B.-Y.; Stanghelle, J.K.; Røisland, M.; Winther, A.; Pajunen, P.-A.; Garen, T.; Flatø, B. Efficacy
of Rehabilitation for Patients with Ankylosing Spondylitis: Comparison of a Four-Week Rehabilitation Programme in a Medi-
terranean and a Norwegian Setting. J. Rehabil. Med. 2011, 43, 534–542, doi:10.2340/16501977-0804.

Environ. Sci. Proc. 2021, 3, x FOR PEER REVIEW 6 of 4
16. Zijlstra, T.R.; van de Laar, M.A.F.J.; Bernelot Moens, H.J.; Taal, E.; Zakraoui, L.; Rasker, J.J. Spa Treatment for Primary Fibrom-
yalgia Syndrome: A Combination of Thalassotherapy, Exercise and Patient Education Improves Symptoms and Quality of
Life. Rheumatology 2005, 44, 539–546, doi:10.1093/rheumatology/keh537.
17. Zijlstra, T.R.; Braakman-Jansen, L.M.A.; Taal, E.; Rasker, J.J.; van de Laar, M.A.F.J. Cost-Effectiveness of Spa Treatment for
Fibromyalgia: General Health Improvement Is Not for Free. Rheumatology 2007, 46, 1454–1459, doi:10.1093/rheumatol-
ogy/kem157.
18. de Andrade, S.C.; de Carvalho, R.F.P.P.; Soares, A.S.; de Abreu Freitas, R.P.; de Medeiros Guerra, L.M.; Vilar, M.J. Thalasso-
therapy for Fibromyalgia: A Randomized Controlled Trial Comparing Aquatic Exercises in Sea Water and Water Pool. Rheu-
matol. Int. 2008, 29, 147–152, doi:10.1007/s00296-008-0644-2.
19. Emmanuel, T.; Lybæ k, D.; Johansen, C.; Iversen, L. Effect of Dead Sea Climatotherapy on Psoriasis; A Prospective Cohort
Study. Front. Med. 2020, 7, 83, doi:10.3389/fmed.2020.00083.
20. Antonelli, M.; Donelli, D.; Veronesi, L.; Vitale, M.; Pasquarella, C. Clinical Efficacy of Medical Hydrology: An Umbrella
Review. Int. J. Biometeorol. 2021, doi:10.1007/s00484-021-02133-w.
21. Schuh, A. Climatotherapy. Experientia 1993, 49, 947–956, doi:10.1007/BF02125641.
22. Mead, M.N. Benefits of Sunlight: A Bright Spot for Human Health. Environ. Health Perspect. 2008, 116, A160–7,
doi:10.1289/ehp.116-a160.
23. Westby, T.; Cadogan, A.; Duignan, G. In Vivo Uptake of Iodine from a Fucus Serratus Linnaeus Seaweed Bath: Does Volatile
Iodine Contribute? Environ. Geochem. Health 2018, 40, 683–691, doi:10.1007/s10653-017-0015-6.
24. Antonelli, M.; Donelli, D. Hot Sand Baths (psammotherapy): A Systematic Review. Complement. Ther. Med. 2019, 42, 1–6,
doi:10.1016/j.ctim.2018.10.020.
25. Moses, S. Health Effects of Dead Sea Climatotherapy on Patients with Heart and Lung Diseases. Anales de hidrología médica
2012, 5, 11–19.
26. Nilsen, L.T.N.; Søyland, E.; Krogstad, A.L. Estimated Ultraviolet Doses to Psoriasis Patients during Climate Therapy. Photoder-
matol. Photoimmunol. Photomed. 2009, 25, 202–208, doi:10.1111/j.1600-0781.2009.00443.x.