The anticancer effect of alkaline water (pH above 7) is at present a controversial topic of hot discussion. It is believed that acidogenic diets can cause the blood which has a normal physiological pH of approximately 7.4 (slightly alkaline) to become too acidic (pH less than 7), hence increasing the risk of cancer. Such a notion stems from previous research findings which revealed the presence of an acidic microenvironment around cancer cells which is thought to be one of the hallmarks of the disease. Therefore, proponents of alkaline water assert that drinking alkaline water can modify the pH of blood and other parts of body to above 7 which can therefore prevent cancer or stop its growth. However, does this claim have any scientific merit?
Blood pH has to be tightly regulated between pH 7.35 and 7.45 as enzymes which facilitate the biological processes in our cells can only function within this narrow pH range. A series of physiological mechanisms are present in the body to regulate the blood pH so it stays within this range. For instance, any excess in acid or alkaline in your blood is simply filtered out by your kidneys to be excreted in your urine. This explains why the pH of your urine can fluctuate after consuming certain food or drinks but this is by no means a true reflection of your overall bodily pH.
As blood circulates around the body to supply oxygen and nutrients to all cells whilst removing CO2 and waste, it also buffers the pH of the organs and tissues to approximately 7.4. As you would expect, a significant change of pH beyond this range can be life-threatening!
When it comes to your diet, the food and water that you consume will first pass through your stomach with a pH range of 1.5 -3.5 (acidic) before being neutralized by the digestive juice in your small intestine with a pH range of 6 – 7.4 (acidic to alkaline). Essentially, whatever you drink or eat would end up having the same pH as the small intestine before being absorbed!
Having seen how tightly-controlled is the pH of our body, the argument that alkaline water can actually help in cancer prevention and/or treatment by alkalinizing your body is fundamentally flawed. While numerous studies have demonstrated the links between dietary habits (the type of food you consume and its content which may be carcinogenic) and cancer risk, there is no evidence to suggest a direct link between diet-induced low pH and cancer.
It is worth pointing out that, the acidic microenvironment surrounding cancer tumours is a result of higher than normal metabolic rate of cancer cells compared with normal healthy cells. Scientists are still hard at work to see if this could be exploited to our advantage in optimizing future cancer treatment although the use of alkaline water for this purpose is of little scientific basis.
- Fenton, T., & Huang, T. (2016). “Systematic review of the association between dietary acid load, alkaline water and cancer.” BMJ Open 6(6): e010438.