Alkalinity vs Acidity

The human body needs to keep a pH level of around 7.35-7.45. If that sounds like gibberish to you, don’t worry I’ll explain. Colloquially, pH stands for ‘potential of Hydrogen’ but in Chemistry terms it is defined as the decimal logarithm of the reciprocal of the hydrogen ion activity in a solution.

A mouth full for sure. Basically the scale determines whether a liquid is acidic or basic (alkaline). A value of 7 is neutral and extremes of either end say for instance 1 or 14 are dangerous and corrosive.

Now, our human body is a remarkable piece of ingenuity. It is designed to continuously monitor, replicate and if necessary, correct abnormalities at the cellular level. We as humans take all this for granted. We think that we can eat and drink whatever we want and then deal with the immediate effects and consequences. We overload with sugar, artificial additives, fats and a myriad of other potentially hazardous substances without thinking about long term effects. (Obesity being only one effect due to it’s visibility). There are plenty of chronic illnesses which not only relate to dietary intake but alarmingly, recent research indicate a growing concern that these illnesses may possibly stem from dietary habits.

So, our human body regulates our blood pH to the levels mentioned in the opening paragraph. There is a lot of controversy and mis information around the internet concerning peoples claims of being acidic. Some of these claims may have come from celebrities which for some reason masses gravitate towards without even checking the veracity of their claims. Now, if they bought a pH litmus tester and tested their skin, it would’ve come back very acidic (pH 4-6.5). Our skin is designed that way to keep out nasties. It is an acidic mantel which acts as a protective barrier to the environment against microbial growth. If they tested their urine, they would have come back with mixed results (can be alkaline or acidic) due to renal acid excretions determined by their dietary intake. Neither of these tests indicate our blood pH levels. Our blood pH remains fairly constant.

However, there are studies which determine that certain categories of foods cause potentially high renal acid loads into the urine and other categories of foods have a negative renal acid load in the urine. ¹Remer T, Manz F. Estimaion of the renal net acid excretion by adults consuming diets containing variable amounts of protein. American Journal of Clinical Nutrition. 1994;59(6):1356-1361. ²Remer T. Influence of diet of acid-base balance. Seminars in Dialysis. 2000;13(4):221-226.

Recent pop culture have used words like ‘acid producing foods’ or have listed foods in either an acidic column or an alkaline column. Due to the crude nature in which these foods are listed, there are many debunking sites that go on to prove how these certain foods are either not acidic or not alkaline according to the posted lists. The most common one I come across are citruses such as lemons and oranges. You’ve probably noticed all of these in the alkaline column, when most people know that these fruits contain citric acid which obviously categorises them as acidic. So really, a more informative way of communicating the important aspects of how foods interact with our body chemistry is to determine their renal acid load on our urine. This in turn gives a clear correlation of how foods prompt our human bodies to regulate our pH by acid dumping into our urine. Citrus fruits have a negative renal acid load. Now you know why they are commonly listed as alkaline producing. It’s a very clumsy way of describing citrus and also at its core, you now know it is also incorrect. A more precise way of stating how citrus fruits benefit us is that our bodies can extract the many nutrients without producing a renal acid load that needs to be dumped into our urine.

A general rule of thumb would be plant based unprocessed foods have either a negative to very low renal acid load and meat, more complex processed foods including animal by products have a much higher renal acid load. ³Refer T. Influence of diet on acid-base balance. Seminars in Dialysis. 2000;13(4):221-226 Calcium phosphates present in our bones and blood respond to acid overloads by releasing into our systemic circulation to bring about pH homeostasis.⁴Frassetto L, Morris Jr. R.C. RC, Jr., Sellmeyer DE, Todd K, Sebastian A. Diet, evolution and aging-the pathophysiologic effects of the post-agricultural inversion of the potassium-to-sodium and base-to-chloride ratios in the human diet. European Journal of Nutrition. 2001;40(5):200-213. So there is good evidence and correlation between a high meat diet vs high plant based diet that will either cause high renal acid load or negative renal acid load. Depending on the acid load to our bodies, calcium will be leached from our bones creating a higher risk in osteoporosis and such deseases.