These days we are given all sorts of advice on healthy eating. There is much controversy about what actually constitutes a healthy diet. Readers of these blogs will know that there are many criticisms of the current official recommendations. There is a convincing case that complying with these will do more harm than good. Furthermore there is considerable variation in how individuals respond to a particular diet. Therefore it would be very helpful if there was a simple test which would enable people to assess their progress towards achieving good health.
In fact there is evidence which indicates that this can be done by monitoring the pH, which is a measure of the acidity/alkalinity of the body. The pH is a log scale with the range from 0 to 14. Low values are acid and high values are alkaline. A value of 7 is neutral (neither acid nor alkaline). The body pH can be measured using litmus strips on a sample of saliva or urine. The optimum value is about 7.5 which is slightly alkaline. The strips are readily available and inexpensive. It is quite easy for individuals to check their own pH themselves.
Metabolic syndrome (MetS) is defined as a condition characterised by a number of metabolic features including low HDL Cholesterol, raised triglycerides, hypertension, obesity and insulin resistance. These are invariably associated with common chronic diseases such as diabetes, heart disease, various cancers and all-cause mortality. In a recent study with 148 participants it was found that as the number of MetS features increased the pH of the urine decreased progressively. For those with no features the pH was 6.15 but for those with 4 features it had fallen to 5.7 (1).
In a recent European study a total of 66,484 women were followed for 14 years. During this period there were 1,372 cases of type 2 diabetes (T2D). It was found that those with a high acid-forming potential had a much higher incidence of T2D than those with a low value. Interestingly the difference was greater for those with a “normal” Body Mass Index (BMI) than for those who were “overweight“ with a BMI >25 (2). This was the first time that a large prospective study has demonstrated that the dietary acid load was positively associated with T2D risk, independently of other known risk factors,
Other studies have shown that the incidence of T2D is higher in people with a low pH in their urine when compared with those who have a higher urinary pH. The low pH was associated with the uric acid and the presence of stones in the urine. It was found that this condition was prevalent in patients with glucose intolerance and T2D (3).
The famous German Nobel Prize winner, Otto Warburg, discovered that there is only one cause for cancer which is the replacement of the respiration of oxygen in normal body cells by the fermentation of sugar. All normal body cells meet their energy needs by the respiration of oxygen but cancer cells depend on sugar as a source of energy for the fermentation process. Because of this crucial difference between cancer and normal cells, this knowledge can be utilised to devise methods of curing the disease. Protocols which deprive the body of sugar are proving to be effective in this context. Furthermore the fermentation causes the immediate environment of cancer cells to become acidic and therefore reduce the pH below the optimum value of 7.4.
In a highly significant investigation it was noted that the pH range of tumours in mice was between 6.5 and 6.9 (compared with 7.2-7.5 for normal tissue). When the pH was raised by treatment with sodium bicarbonate (baking soda) this resulted in significant reductions in the number and size of metastases to the lungs, intestine and diaphragm (5). The tumours used were models for breast and prostate cancer in humans. This is a practice which has been used successfully for the treatment of various forms of cancer.
Consequently there is considerable interest in understanding the relationship between various foods and their impact on the pH. Various attempts have been made to determine the impact of different foods on the pH of the body.
Chris Woollams has spent years developing his Canceractive website which contains an enormous amount of reliable information which relates to the prevention and curing of cancers. People diagnosed with cancer invariably have an acidic pH and there are strong indications that the consumption of a high proportion on of foods which are known to be alkaline can help to prevent and even cure cancer (6).
These include:
Vegetables
Beetroot, Cabbage, Carrots, Cauliflower, Celery, Cucumber, Fresh green beans, Lettuce
Mushrooms, Parsnips, Potatoes, Spinach, Swede, Watercress
Fresh fruits
Apple, Avocado, Blackberries, Blackcurrants, Cherries, Grapes, Lemons
Olives, Pears, Olives, Raspberries
Others
Fresh ginger, Fresh juices, Green tea, Olive oil, Seeds
By contrast, here are some of the foods which are acidic producers:
Vegetables
Brussel sprouts, Lentils, Peanuts, Rhubarb, Tomatoes
Fruits
Bananas, Grapefruit, Oranges, Plum, Prunes
Others
All alcohol, Coffee, Fizzy drinks, Sauce, Sugar, Sweets

The above list is certainly not meant to be comprehensive and the degree to which individual foods can exercise their effect on the pH does vary and of course will be influenced by the amount consumed.
For those whose pH levels are in the acidic range it should be possible to raise it into the alkaline range by making adjustments to the diet. The alkaline-producing foods should be reduced at the expense of the acid-producing ones. However it is critical to understand that it is the balance that is important. While there are some acid-producing foods which should be kept to a minimum such as fizzy drinks and sugar, there are others such as Brussel sprouts and tomatoes which should be include in a healthy diet. The above information is simply a guide which hopefully will enable a person to try out different possibilities and discover what actually works and what is feasible.
The significant advantage of the pH is that it provides a means by which anyone can monitor their progress in response to dietary adjustments. As things stand at present we do not have absolute proof that the rationale is sound but it is certainly worth trying. There is no suggestion that attempting to alter the pH by dietary means will cause any possible harm. On the face of it, pH should be a routine check as already applies to body temperature or blood pressure. It would be extremely valuable if the research could be instigated which would explore how this could be achieved.

REFERENCES
1. N M Malouf et al (2007) Clinical Journal of the American Society of Nephrology 2 (5) pp883-888
2. G Fagherazzi et al (2013) Diabetologia doi:10.1007/s00125-013-3100-0
3. K Sakhaee et al (2002) Kidney International 62 (3) pp 971-979
4. http://www.healingcancernaturally.com/warburgcancer-cause-prevention.html
5. I F Robey et al (2009) Cancer Research 69 (6) pp 2260-2268
6. http://www.canceractive.com/cancer-active-page-link.aspx?n=978