Increased Incidence of Breast Cancer Due to Long Exposure of Light

Abstract

The disturbed circadian rhythm due to long exposure to varied photo periods or to artificial light during night time (LAN) results in hormonal imbalance. The epidemiological survey indicates a clear difference in the incidence of breast cancer (BC) in countries closer to the poles and to the equator. Long-term exposure to LAN during sleep cycle is found to be the root cause of many health problems. Light dependent conversion of melatonin from serotonin plays a major role in cancer development. In rat model it is shown that levels of melatonin are always inversely proportional to oestradiol in the blood. Melatonin decreases the formation of oestrogens (mitogenic hormone) from androgens via aromatise inhibition. In a pilot study we have shown that in menopausal blind (risk age for BC) women the prevalence of BC is very low (1:169; Risk Rate (RR); Cumulative Risk (CR)35-64 age), compared to sighted women (1:78; CR, 35 - 64 age). Data was collected from a total of 2060 blind subjects (18.8% being <40 years of age and 81.2% above 40 years). Partially blind subjects have 11% greater risk of developing BC than those who are totally blind (RR=1.106; 95% CI=.352 to 3.472). Other established risk factors for BC are ineffective in blind. The blind women model (proposed in this study) suggests that dark hours are essential in our daily routine. By management of proper circadian rhythms better management of various endocrine diseases including hormone dependent cancers can be achieved.

Assessing the effects of artificial light at night on biodiversity across latitude – Current knowledge gaps

“…More information is certainly present but not necessarily in papers addressing directly ALAN as previously noted (Rich & Longcore, 2006). In comparison, using the combination of keywords (tropic* OR equat*) and "artificial light", "artificial" AND "light", or "light pollution", we identified 11 references (Bennie, Duffy, et al, 2015;Dorado-Correa, Rodríguez-Rocha, & Brumm, 2016;Erkhert, 1976;Frank, Gabbert, Chaves-Campos, & LaVal, 2019;De Freitas, Bennie, Mantovani, & Gaston, 2017;Gineste et al, 2017;González-Bernal, Greenlees, Brown, & Shine, 2016;Gupta & Pushkala, 2016;Lewanzik & Voigt, 2014;Rivas et al, 2018;Thakurdas et al, 2009). A final search using the combination ("artificial light" OR "light pollution") AND "latitud*" yielded 59 hits but only four additional and partly relevant references.…”

Sphingomonas paucimobilis complicating vaginal fluid cultivation. A rare case

“…These studies univocally proved that expose to light and no time to give chance for conversion of serotonin to melatonin which is a dark reaction raises incidence of BC [12,15]. This may be due to lower levels of melatonin in the blood because serotonin is not able to get converted in to melatonin and whole hormonal milieu changes.…”

“…Epigenetic plays an important role in such cases. Prolonged exposure to light and missing dark periods not only change melatonin levels in the body but may also bring about gene mutation and methylation which in turn change gene expression that may be responsible for higher incidence of BC cancers [11][12][13][14][15][16][17][18][19].…”

Chronopharmacology: A New Approach for Drug Delivery Schedules

“…The continuation of life is by reproduction the only biological function of our body is to reproduce; the other functions are evolved to help the reproduction Rhythm is defined as "Regular recurrence of quantities or accents of an event". Reproduction is rhythmic and if it becomes non-rhythmic, individuals cannot reproduce (1)(2)(3)(4). Until puberty, reproductive rhythm does not exist in males or females and therefore, they are not able to reproduce (5)(6)(7).…”