There is evidence from research that hard water worsens atopic dermatitis symptoms. However, is calcium-rich water really harmful to health? And is a water softener for the shower worthwhile?
Calcium and magnesium determine water hardness
When it rains, rainwater seeps through rocks. Depending on the composition of the rocks, minerals enter the groundwater. Therefore, hard water contains more minerals, namely calcium and magnesium, than soft water. Hard water is often associated with lime deposits – a combination of calcium, oxygen, and carbon. Lime becomes visible in the white deposits and stains, for example, in the kettle. The mineral content varies depending on the region, but you can inquire about it at the local utilities in your area.
While household appliances do not tolerate high lime content well, our bones and muscles actually benefit from it. However, drinking hard water cannot meet the daily requirements for magnesium and calcium. In general, hard water does not harm overall health. However, it could be different for atopic dermatitis.
Infants: atopic dermatitis due to calcium-rich water
If water hardness affects atopic dermatitis, more cases of atopic dermatitis should occur in regions where the water is very hard. Indeed, a study from England found this effect. In Southern England, where the water is harder than in the North, more cases of atopic dermatitis were observed in infants. The authors of the study concluded that water hardness has a strong influence on the development of atopic dermatitis in the first three months of life.
However, the association is not unequivocal in all scientific studies. Yet, an overview of several studies found that the risk of developing atopic dermatitis due to hard water might be particularly increased for young children. There is evidence that children in regions with hard water have a 28% higher risk of developing atopic dermatitis.
So far, the study results have been inconclusive
The influence of hard water on eczema in adults has been less studied. However, there are indications that hard water may worsen the skin barrier even in adults with eczema. This effect could be temporary and relatively small. The existing research does not suggest that water hardness triggers eczema in older children or adults.
Many study results on this topic are currently uncertain to interpret or contradictory. However, there are some plausible considerations behind the influence of hard water on the skin:
- Calcium and magnesium, which are commonly found in hard water, could potentially damage the skin barrier, leading to skin dryness and eczema.
- Hard water is also associated with the alkalinity of water. This means that harder water with a higher pH level can also disrupt the skin barrier.
Is a water softener worth it?
Infants and children in elementary school are in a life stage where the skin barrier is still developing. Therefore, water hardness, along with other factors such as environmental and genetic elements, could contribute to the development of atopic dermatitis. Some parents may consider whether it is worthwhile to invest in a water softener.
A study systematically examined the effect of water softeners on atopic dermatitis in children. However, this study found no effect of water softening compared to normal treatment. Only some parents reported a subjective improvement in symptoms, likely due to a placebo effect. Therefore, it is not currently recommended to purchase a water softener for children with atopic dermatitis.
However, in the Nia app, you can individually add the trigger “water hardness.” This allows you to observe over an extended period whether your atopic dermatitis symptoms decrease in locations with soft water or a water softener.
Sources:
- Jabbar-Lopez, Z. K., Ung, C. Y., Alexander, H., Gurung, N., Chalmers, J., Danby, S., Cork, M. J., Peacock, J. L., & Flohr, C. (2021). The effect of water hardness on atopic eczema, skin barrier function: A systematic review, meta-analysis. Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology, 51(3), 430–451. https://doi.org/10.1111/cea.13797 (external)
- Apotheken (external), Zugriff am 01.12.2022
- Quarks (external), Zugriff am 01.12.2022
- Thomas KS, Dean T, O’Leary C, Sach TH, Koller K, Frost A, et al. (2011) A Randomised Controlled Trial of Ion-Exchange Water Softeners for the Treatment of Eczema in Children. PLoS Med 8(2): e1000395. https://doi.org/10.1371/journal.pmed.1000395 (external)
- Lopez, D. J., Singh, A., Waidyatillake, N. T., Su, J. C., Bui, D. S., Dharmage, S. C., Lodge, C. J., & Lowe, A. J. (2022). The association between domestic hard water and eczema in adults from the UK Biobank cohort study. The British journal of dermatology, 187(5), 704–712. https://doi.org/10.1111/bjd.21771 (external)
- Derma.plus (external), Zugriff am 01.12.2022
