Does the research support photobiomodulation (or low level laser or light) therapy and lactation-related nipple pain?

What is photobiomodulation therapy, also known as light or low level laser therapy?

Since the 1960s, photobiomodulation therapy (PBMt) using low-level laser therapy (also referred to here as ‘light therapy’) has been used in a variety of conditions to reduce pain and inflammation and stimulate wound healing, by promoting cell regeneration and proliferation. Research has clearly demonstrated benefits in (non-nipple, non-lactation related) tissue healing.

A range of cellular photoreceptors are implicated in the mechanism for light therapy. Light therapy modulates

• Molecular, cellular and tissue processes which increase protein synthesis and cell proliferation.18

• Inflammatory mediators, cytokine production and growth factors, which reduce pain and swelling and promote wound healing.

Light photons have been proposed to have the following theoretical effects

• Temporary release of nitric oxide from binding site on cytochrome C oxidase

• Stimulation of adenosine triphosphate (ATP) synthesis via activation of electron transport chain

• Stimulation of 'reactive oxygen species', which are short lived and highly reactive molecules. When these exist in low levels, and are stimulated, they activate cell survival signalling pathways.

These mechanisms in turn are hypothesised to cause significant increase in cell activation, respiration and transcription, through numerous intracellular pathways – promoting wound healing, regeneration and proliferation of cytokines.

What studies have been done investigating light therapy for lactation-related nipple pain and damage?

There are only a small number of studies investigating the impact of light therapy upon lactation-related nipple pain, with ambivalent results, and much yet to be clarified including possible most useful doses and settings. In short, there is no reliable evidence to support the use of laser or light therapy for nipple pain and damage.

• In 1999, Pietschnig et al, first evaluated the effects of light therapy for the management of nipple pain in a small non-randomised/controlled study, with findings demonstrating a reduction in nipple pain.19 However, as participants also used lanolin cream concurrently, the effect could not be isolated to the application of light therapy.

• The next study lead by Posso et al in 2007, compared one application of light therapy to placebo in 40 post-natal women. The results demonstrated a significant reduction in nipple pain at 1 and 10 minutes after light therapy application compared to placebo.20 Further pilot and case studies have since been conducted, reporting preliminary evidence that light therapy reduces nipple pain. 21-23

• In 2016, Coca et al conducted a triple-blinded RCT of 59 participants randomised to receive either placebo or light therapy for 3 sessions at 0, 24 and 48hours after group allocation in addition to standard care. Results demonstrated a significant reduction in nipple pain for the light therapy group after the first and second applications. The third application was not analysed due to a significant drop out rate as participants were discharged from hospital.24

• In 2016 Buck, Eckereder & Amir published a case study of two postnatal women with nipple pain who were provided with a novel application of 3 sessions of light therapy within a 24 hour period, providing early findings of a significant reduction in nipple pain and improved healing.22

• A 2018 systematic review of prevention and treatment for lactation-related nipple pain and fissures by Niazi et al claimed low level laser therapy was beneficial because of

  • Increased blood flow rate because of vascular dilation and angiogenesis (generation of new capillaries)

  • Stimulation of growth factors

  • Increased proliferation of fibroblasts and also collagen synthesis

  • Decreased prostaglandin levels which lead to increase wound healing rate and decreased pain and inflammation.

• A follow-up study in 2019 by Camargo et al performed just one session of light therapy compared to placebo using higher energy settings than used in their previous study and showed no changes in reported nipple pain. The authors reflected that more applications of light therapy with lower energy settings would have been more effective and emphasised the need for further studies investigating different parameters, particularly low fluence settings.25

• A 2024 systematic review and meta-analysis by Noziomoto et al of nonpharmacologic interventions for the treatment of nipple pain and damage in lactation, which selected only randomised controlled trials, confirmed that photobiomodulation had only an uncertain effect compared with placebo 24 hours after application.

What are the limitations of existing studies investigating light therapy in nipple pain and damage?

1. As light therapy has a biphasic dose response, optimal parameters still need to be investigated. Settings outside the dose range will either be insufficient (if the dose is too low) or may inhibit the therapeutic potential of light therapy and its effects on wound healing if the dose is too high.26

2. Currently, the optimal time interval between light therapy applications is understudied, with most studies administering light therapy 24 hours apart.18

3. It is widely accepted that the first line of treatment for nipple pain is a fit and hold intervention. However, approaches to fit and hold remain experience and opinion-based.27 You can find out more here. The gestalt method is the only fit and hold intervention with preliminary data on objective measures (using ultrasound measures), demonstrating intra-oral changes before and after the intervention. All existing trials concerning nipple pain or breastfeeding problems fail to stipulate the particular approach or biomechanical model used by the lactation consultant prior to the decision to proceed to light therapy, frenotomy, bodywork, or other treatment for nipple pain.

4. Powell et al28 concluded that “Although certain doses of laser increased MCF-7 [human breast adenocarcinoma] cell proliferation, multiple exposures had either no effect or showed negative dose response relationships. No sign of malignant transformation of cells by laser phototherapy was detected under the conditions applied

5. Zecha et al29 suggest that it is “…unlikely that PBM has carcinogenic effects on normal cells”.

6. In a study of red light PBM in tissues that harboured cancer cells, Myakishev-Rempel et al30 demonstrated “…no measurable effect on tumour growth”.

7. Laakso and Parsons31 found that in “…an immune-absent malignant murine model, laser had no effect on tumour growth…”

Recommended resources

Does the research support photobiomodulation (or low level laser or light) therapy and lactation-related nipple pain?

References

Araujo AR, Nascimento ALV, Camargos JM, Silva FS, Faria NVMG. Photobiomodulation as a new approach for the treatment of nipple traumas: a pilot study, randomized and controlled. Fisioter Bras. 2013;14(1):20-26.

Buck ML, Eckereder G, Amir LH. Low level laser therapy for breastfeeding problems. Breastfeeding Review. 2016;24(2):27.

Camargo BTS, Coca KP, Amir LH, Correa L, Aranha ACCM, K O, de Vilhena Abrao ACF. The effect of a single irradiation of low-level laser on nipple pain in breastfeeding women: a randomized controlled trial. Lasers in medical science. 2019:1-7.

Chaves MEDA, Araujo AR, Santos SF, Pinotti M, Oliveira LS. LED phototherapy improves healing of nipple trauma: a pilot study. Photomedicine and laser surgery. 2012;30(3):172-178.

Chung H, Dai T, Sharma SK, Huang YY, Carroll JD, Hamblin MR. The nuts and bolts of low-level lasert (light) therapy. Annals of biomedical engineering. 2012;40(2):516-533.

Coca KP, Marcacine KO, Gamba MA, Correa L, Aranha ACC, de Vilhena Abrao ACF. Efficacy of low-level laser therapy in relieving nipple pain in breastfeeding women: a triple-blind, randomized, controlled trial. Pain Management Nursing. 2016;17(4):281-289.

Huang YY, Chen ACH, Carroll JD, Hamblin MR. Biphasic dose response in low level light therapy. Dose-response. 2009;7(4).

Pietschnig B, Pani M, Kafer A, Bauer Wais E, Lischka A. Use of soft laser in the therapy of sore nipples in breastfeeding women. Adv Exp Med Biol. 2000;478:437-438.

Posso I, Goncalves S, Posso M, Filipini R. Control of nipple pain during breastfeeding using low level laser therapy. Regional Anesthesia and Pain Medicine. 2007;32(5):185.