The story of a girl aged three who recovered from kidney cancer after drinking water from the spring in Lourdes, France, raised increasing interest about hydrogen water effects on cancer prevention and treatment. Although scientifically not proved up to date, evidences show that hydrogen water helps to keep a lower level of harmful ROS; therefore with a lower likelihood of cancer.
Molecular hydrogen effects on neoplastic diseases have been documented in pilot studies and have shown to have therapeutic potential. Hydrogen rich water has shown to inhibit tumour growth as a result of its capability to reduce oxidation products, that is, ROS (Dixon, 2013). There is evidence of its beneficial effect on tongue cancer and fibrosarcoma human cells and it has been observed that it protects against thymic lymphomas induced by radiation. This is because hydrogen has the capability to scavenge harmful ROS, which causes cancer. (Wang, 2008; Ye, 2008).
Since ROS levels are usually high in tumour cells due to the oncogenes activation, to the relative lack of blood supply or to other variations and since ROS are involved from the very beginning, during progression and metastasis of cancer, it is considered that the ROS are oncogenic.
Some studies state therapies based on ROS manipulation, so that those with beneficial /antioxidant) effect increase and those harmful (pro-oxidant) decrease.
The vascular endothelial growth factor is a key mediator in tumour angiogenesis. Tumour cells are much more exposed to oxidative stress than normal cells. Many studies have shown that intracellular redox state (oxidation/reduction) is closely linked to the VEGF expression pattern.
This study shows that water reduced by electrolysis reduces the transcription of the gene which codes the VEGF and the secretion of this protein by inactivation of extracellular signals regulated by kinases (ERK).
The antioxidant effect and neutral pH of hydrogen rich water may reduce oxidative stress in tumour cells and cause anticancerous effects since the specific characteristics of these cells (increased cellular proliferation , DNA synthesis, survival , cell migration, invasion , tumor metastasis and angiogenesis) are closely associated with ROS.
Neutral hydrogen water (NHW) properties and effects have been examined on tumour cells and it has shown to reduce hydroxyl radicals (?OH). Neutral hydrogen water can neutralize ROS and y provide an antioxidant effect both inside and outside cells. This antioxidant property may be responsible for its preventive effect on the formation of cell colonies. Recently, the NHW inhibiting effects on tumour angiogenesis have been shown, a prerequisite for tumour invasion; therefore it is expected to be effective against metastasis and cancer proliferation.
On the other hand, it is thought that NHW characteristics such as abundance of hydrogen and neutral pH may empower the antioxidant potential in comparison with conventional alkaline reduced water since it saves the consumption of other antioxidants such as vitamin C.
In addition, this study confirms the excellent stability of NHW in the humna oral cavity as well as a high power of retention comparing to tap water. This is what causes its antioxidant and anticancerous effect. This fact may imply that the human oral cavity may be one of the candidate places where the NHW can show its effects, since hydrogen does not disappear so easily after the first contact of water inside the mouth.
In human tongue carcinoma cell cultures, NHW has shown to inhibit clonal growth of these cells compared to the one of normal cells and it also inhibits the tumour invasion of fibrosarcoma cells. It suppresses intracellular oxidation as well. Although it is expected that NHW becomes a useful strategy for clinic application in cancer therapy , these in vitro findings must be confirmed with in vivo studies.
Most of the damage induced by ionizing radiation is caused by the hydroxyl radical (OH) followed by water radiolysis, another important source of free radicals. Molecular hydrogen has shown to have radioprotector effects since it reduces oxidative stress induced by radiation without compromise the anti-tumour effects of therapy.
In patients undergoing radiotherapy, the daily intake of hydrogen water results in a preventive strategy against oxidative stress damage caused by radiation.
It is widely known that ionizing radiation (IR) causes oxidative damage and consequently apoptosis mainly due to hydroxyl radicals production (?OH) as a result of water radiolysis.
The protective effect of molecular hydrogen (H2) on mice irradiated cells has been shown for the first time. This effect has been confirmed in some other laboratories with several animal models.
In humans, a random and placebo-controlled study showed that H2 intake may improve quality of life in patients treated with radiotherapy for liver tumours. These promising findings suggest that H2 has potential as a radio-protector agent efficiently and with no toxicity.
Many radiotherapy side effects are associated with an increase in oxidative stress and inflammation due to reactive oxygen species (ROS) generation during radiotherapy. Kang et al. studied the effects of daily intake of hydrogen water (1,5-2 litres per day) for 6 weeks in 49 patients undergoing radiotherapy due to hepatic tumour. Hydrogen avoided the increase in ROS levels caused by radiation, it kept the endogenous antioxidant capacity and improved quality of life of patients. In addition, hydrogen water avoided the lack of appetite typical in these situations; all of this with no effect on the tumour response to radiotherapy.
Excessive exposion to ionizing radiation causes damage to tissues and provokes the so-called acute radiation syndrome. 60-70% of cellular damage induced by ionizing radiation is caused by the hydroxyl radical (.OH). Treatment with hydrogen water reduce oxidative stress markers caused after radiation and it has benefits in patients undergoing radiotherapy, improving quality of life. These promising findings suggest that H2 has potential as a radio-protector agent efficiently and with no toxicity.
Hydrogen rich water (H2) may alleviate cisplatin-induced nephrotoxicity without compromising anti-tumour activity, both oral intake and inhalation.
The levels of apoptotic cells and malondialdehyde (MDA ) in plasma and 8-OHdG intestinal significantly were reduced whenever cells or mice were treated with H2 after irradiation. This suggests that H2 intake might also be beneficial in cancer radiotherapy. To sum up, H2 may counteract side effects typically observed during chemotherapy, radiotherapy and hemodialysis, thus improving quality of life of the patient.
MDA: indicator of lipid peroxidation measured by ROS.
8-OHdG: DNA oxidation marker.
Cytotoxic drugs such as cisplatin are widely used in chemotherapy but they have significant side effects, some of them associated with oxidative stress and inflammation. Hydrogen rich water administration may alleviate renal toxicity induced by cisplatin without compromising the anti-tumour activity of chemotherapy.
Hydrogen effectively attenuates the side effects of cisplatin reducing oxidative stress.
Hydrogen rich water intake also reduces oxidative stress, mortality and weight loss induced by cisplatin in mice. Hidrogen rich water also improved the metamorphosis that accompanies decreased apoptosis in the kidney as well as nephrotoxicity, evaluated by serum creatinine and BUN (blood urea nitrogen). Hydrogen did not affect anti-tumour activity of cisplatin against in vitro cancer cell lines and in in vivo tumor-bearing mice, despite their protective effects against cisplatin -induced toxicity.
Hydrogen has potential to improve the quality of life of patients during the chemotherapy to efficiently mitigate the side effects of cisplatin.