Negative air ionization therapy (NAIs) uses air ionisers as a non-pharmaceutical treatment for respiratory disease,

allergy Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...

, or stress-related health conditions. The mainstream scientific community considers many applications of NAIs to be

pseudoscience Pseudoscience consists of statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method. Pseudoscience is often characterized by contradictory, exaggerated or falsifiability, unfa ...

. Many negative ion products release

ozone Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lo ...

, a chemical known to cause lung damage.

Research

For Seasonal Affective Disorder (SAD), a

randomized controlled trial A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical te ...

(RCT) comparing high (4.5x10¹⁴ ions/second) and low (1.7x10¹¹ ions/second) flow rate negative air ionization with

bright light therapy Light therapy, also called phototherapy or bright light therapy is intentional daily exposure to direct sunlight or similar-intensity artificial light in order to treat medical disorders, especially seasonal affective disorder (SAD) and circadi ...

found that the post-treatment improvement percentage was 57.1% for bright light, 47.9% for high-density ions and 22.7% for low-density ions. An older RCT conducted by the same authors also found air ionization effective for SAD. A 2007 review considers this therapy "under investigation" and suggests that it may be a helpful treatment for SAD. An RCT comparing the short-term effects of bright light, an auditory stimulus, and high and low-density negative

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s on mood and alertness in mildly depressed and non-depressed adults found that the three first (active) stimuli, but not the low-density placebo, reduced depression on the

Beck Depression Inventory The Beck Depression Inventory (BDI, BDI-1A, BDI-II), created by Aaron T. Beck, is a 21-question multiple-choice self-report inventory, one of the most widely used psychometric tests for measuring the severity of depression. Its development mark ...

scale. The auditory stimulus, bright light, and high-density ions all produced rapid mood changes - with small to medium effect sizes - in depressed and non-depressed subjects. A 2008 clinical trial showed that negative ion generators produced a smaller percentage of change on SIGH SAD compared to LED photo-therapy. A separate randomized placebo-controlled study published in May 2010 found that the difference between high-density ion therapy and placebo (dim red light and low-density ions) was not statistically significant. The study concluded that bright white light therapy was significantly more effective than negative ion therapy for treating SAD. Researchers have continued to cite a dearth of evidence about the effects of negative air ionization. "The presence of NAIs is credited for increasing psychological health, productivity, and overall well-being but without consistent or reliable evidence in therapeutic effects and with controversy in anti-microorganisms," researchers wrote in a 2018 article published in the International Journal of Molecular Sciences. While that 2018 study concludes that negative ion therapy has no measurable therapeutic effects, and it is considered to be

by this and previous studies, other studies conclude there are beneficial effects on cognition and mood.

References

{{reflist Alternative medicine

Research

See also

References