Scientists have spent a considerable amount of time investigating the answer to this question in recent years. In fact, this idea that high acid-load diets could have health risks, was put forth by scientists at least 40 years ago.
Before we move into answering the question, let us first make clear some of the terminologies, as well as easily misconstrued notions about pH and the body.
- pH refers to the acidic or basic (alkalinity) of a substance. Low pH (below 7.35) describes something acidic, while high pH (above 7.35) constitutes basic/alkaline substances. The lower the pH, the more acidic, the higher the pH, the more alkaline.
- With regard to food, pH of the pre-consumed food does not translate to the pH or acid/base load in our body. Acid-base load in the human body is affected by salivary & gastric juices, as well as the total composition of the meal consumed (i.e. the acid/base load of foods consumed at the same time affect each other). Note: there are physical conditions that affect our body’s ability to regulate pH, but these are conditions diagnosed by a doctor, and you would likely know about if present.
- In general, the body keeps tight control over its pH. There are no known acute concerns with the effects of pH on diet, rather it is the longer-term/more subtle difference of dietary acid/base load that has scientists pursuing this matter.
So what foods have a high acid load on the body? And what effect do they (potentially) have on the body? …Broadly, animal proteins (milk, meat, cheese, eggs, yogurt) impose a high acid load on the body. However, it also should be noted that our “Westernized” (processed) foods are also responsible for this load (namely those containing phosphoric acid and/or phosphate additives, derived from the mineral Phosphorus). In the form of additives, phosphate & phosphoric acid are easily absorbed by the body, and if you ask me, likely more responsible for the potential acid load problem. Added phosphorus comes in many forms, and it is not a required listing on food nutrition labels - be sure to check the INGREDIENT list for additives like “phosphoric acid” and anything ending with “phosphate,” if you are looking to decrease this dietary additive. Examples of processed foods with high phosphorus content include sodas, nondairy creamers, a variety of processed cereals & grains, meats that have been injected with phosphates for preservation (you’d be surprised at how common). Before you go web-searching the phosphorus content of your diet, remember!: Many foods contain naturally-occurring phosphorus (animal products and beans/peas), but in natural form the acid load is much lighter than that of added forms. When you consider the acid load of these natural foods, don’t forget about their important services to the body! For example, the protein and B vitamins in meat, the vitamin D in eggs, Calcium in cheese, antioxidants and fiber in beans & peas, …just to name a few 😉
As for the potential effects of a high dietary acid load, studies have questioned this subject in relation to bone health, heart health, cancer risk, and more. Not enough evidence has yet been found to solidify that a high dietary acid load does cause or contribute problems with these areas of our health, but there is some out there. I BEG YOU not to go running too far from any foods after reading this information, but do think about your intake. Remember that the combination of foods we eat is what’s really significant. Only when we are at an extreme is when things could be problematic.
The right idea, as with many nutritional concepts is to BALANCE your diet. Do this in the already familiar ways (eat your fruits and veggies, get enough protein, hydrate well…), and also consider the variety of your food sources. If you eat mostly processed foods that include added phosphates AND you don’t balance that with natural foods, then you might need to rethink your potential dietary acid load.
I must admit that even with years of study in nutrition, this topic is especially challenging. The more I read about pH and diet, the more I wonder! That’s science, though. Always asking complicated questions and having trouble reaching the answer! So for now, as the dietary acid load question is still up for debate, don’t drive yourself too crazy over this one.
BOTTOM LINE(S): Eat well! Eat a balanced diet containing as many naturally sourced foods as you can, and if you have a package of cookies or a soda a couple times per week, so what? Try to drink filtered water (labeled “purified” in some way), but remember that your water alone is not going to be your saving grace. Eating to the acid extreme, then trying to “fix” that with special high pH water is not likely going to keep your acid load in check. If you have to choose between tap water and dehydration, go with the tap 😉 Same idea applies to food: choices aren’t going to be all perfect all the time, and that’s ok. Just make an effort, a real effort, and your body will thank you.
Thanks for reading!
-Kate Kirby, MS, RDN, CSSD, RYT-200; yogaleate Owner