But you were referring to and making claims about potential benefits of such treatment with a LED panel/mat, based on research wherein laser is used - as a lot of companies selling these panels do. That is why I said it is comparing apples to pears (or oranges, if you will). I’m mostly taking issue, since these panels are commonly being sold based on these claims.
But then, as said repeatedly: we don’t have the studies that show the effects of using complete panels/mats with LEDs with high power density regularly for a long time over larger areas of the body. Even study authors say that caution is still warranted - as opposed to the companies selling these panels/mats.
I’m aware I’m keeping this discussion going also. But I’d love to be proven wrong - and see studies that do confirm the safety of using high amounts of NIR in direct contact with the skin regularly. At the same time I’m concerned that companies do make these suggestions, while studies are lacking. (Not in the least after having read anecdotal experiences that were disconcerting, but that I have not cited here since they were anecdotal after all. Fact is: we need the studies to be conducted).
Effects of IRA radiation on MMP-1 expression in human skin
“Exposure of cultured primary human dermal fibroblasts has previously been shown to induce MMP-1 mRNA and protein expression. To assess the in vivorelevance of these observations, in this study normal buttock skin of 23 healthy human volunteers was irradiated with a single dose of 360 or 720 J cm−2 IRA radiation (Tables 1, 2 and 3) and subsequently assessed for MMP-1 mRNA (n=15) or protein (n =8; 4 by western blotting and 4 by immunohistochemistry) expression. These doses were chosen, because they correspond to the dose of IRA radiation, which can be achieved in a few hours on a summer day in central Europe. Sensitivity towards IRA radiation, as defined by increased MMP-1 mRNA (>1.5-fold upregulation) or protein expression (>1.5-fold upregulation) was observed in 19/23 volunteers, that is, approximately 80%. As is shown in Figure 1a and Table 1, IRA responsiveness, as well as the magnitude of the response, showed marked interindividual variability. The latter varied from 3- to 14-fold upregulation, as compared with sham-irradiated skin of the same individuals. This variability did not correlate with skin type, sex, or age of the respective volunteers (Tables 1 and 3).”
" Materials and Methods
In vivo irradiation
All in vivo studies were carried out in adherence to the Declaration of Helsinki Principles and were approved by the local ethical committee of the Medical Faculty of the Heinrich-Heine-University in Düsseldorf, Germany. After obtaining informed consent, buttock skin of healthy human volunteers (n=32; non smokers, for further characteristics see Tables 1, 2 and 3) were exposed to a single dose of IRA radiation from a water-filtered IR-A irradiation source (Hydrosun 500; Hydrosun Medizintechnik, Müllheim, Germany). This device emits wavelengths between 760 and 1440 nm (Figure S1) without any contaminating UV radiation as controlled by means of a UVAMETER (Mutzhas, Munich, Germany) and a UV-Dosimeter Type II equipped with a UV6 sensor (Waldmann Medizintechnik, Villingen-Schwenningen, Germany). The IRA output was determined with a Hydrosun HBM1 (Hydrosun Medizintechnik) measuring device and found to be 105 mW cm−2 at a lamp-to-target distance of 40 cm. The IRA radiation doses of 360–720 J cm−2 were applied in 57–114 minutes; none of the volunteers experienced extensive heating. For sham treatment, another area of buttock skin was treated completely identical, except that no IRA was applied. Twenty-four and 48 hours after irradiation, 4-mm punch biopsies were taken from IRA- and sham-irradiated skin sites. Samples were snap frozen and stored in liquid nitrogen until further analysis."
