Acid-base balance (sometimes called acid-alkaline balance) can be a complex and confusing topic. Today, I want to explain the topic in simple terms and give you the essential info you need to consider when you are looking to improve your health. So stick with me and I’ll take you through it from a naturopath’s perspective.
Even if chemistry has never been your thing you might remember back to school days and the lesson on pH. There was talk of “acids”, “bases” and “buffers”. You might recall litmus paper that turned pink or blue when dipped in different substances depending on that substance’s pH. The numbers for pH range from 1 (being very acidic) to 14 being very alkaline (or base) with a pH of 7 being neutral.
Our blood has a normal pH of 7.35-7.45 (just slightly more alkaline than the neutral point of 7). It’s a pretty small range and any variance outside this range has significant detrimental consequences for our health and can constitute a medical emergency. So, as you can imagine, our body has some pretty neat ways of ensuring we maintain that critical number at all times. These systems are our buffering systems.
The problem is, every food and substance we put in our mouth has the potential to impact on our pH, pushing it more one way or the other (remember the litmus paper). Furthermore, our own essential metabolic processes result in end-products which can have an impact on our blood pH.
Don’t confuse acid taste with acid pH*
It’s easy to confuse the concept of acid-alkaline balance with foods that taste “acidic” (e.g. lemons). But what we’re talking about is how that food is metabolised or broken down, and the effect the end substance has on our pH. To take the lemon as an example, it tastes acidic or tart but when digested its effect on our blood is actually alkaline.
We measure the impact of food on our pH by something called the Potential Renal Acid Load (PRAL) which is, in simple terms, a measure of the net acidic effects of different foods once metabolised (and therefore a measure of how hard our bodies need to work to buffer that acid load).
In general, fruit and vegetables have a lower PRAL and therefore an alkalising effect on our bodies. Animal foods (including fish, dairy and eggs), sugar and grains have a higher PRAL and therefore put more acid into your system (which then requires buffering).
As an example, you would need to eat 300g of vegetables to offset the acid load of 100g of meat.
Why do we need to be concerned with our acid-base balance?
If we have these buffering systems to help keep our blood pH in the safe range why do we need to worry if our diet has a higher acid load? Good question!
If you eat a fairly typical Australian diet consisting of meat, dairy, eggs, processed foods, lots of grain foods and sugar but low in fruit and vegetables you will be placing constant demands on your buffering systems. If you smoke, take drugs or drink a large amount of alcohol you further burden your system. Add to this the metabolic by-products of your own biochemistry including the effects of stress, intense exercise, inflammation, disease and aging which all have a net acid load on your body and your buffering systems will be working very hard to maintain that slightly alkaline blood pH.
To do that, we will draw alkalising minerals such as calcium, magnesium and potassium and sodium from our tissues, especially our bone and muscles. We also excrete acid via the kidneys however our ability to do this declines by approximately 1% per year from the age of thirty.
Eventually our buffering systems can’t keep up with the acid burden and we end up in a state of chronic mild metabolic acidosis.
The possible signs of acid-base imbalance
- Mild metabolic acidosis can go unnoticed for years however there are some clues that we look out for that could indicate a problem with your acid-base buffering systems. These include:
- Generalised weakness or unusual muscle fatigue
- Loss of appetite
- Nausea and vomiting or just feeling “off colour”
- Conditions which can be exacerbated or caused by prolonged mild metabolic acidosis include:
- Kidney disease and kidney stones
- Osteoporosis or osteopenia
- Loss of muscle (known as sarcopenia)
- Insulin resistance and high blood glucose
- High blood pressure
- Inflammation and pain
- Difficulty losing weight
- thyroid function
Obviously, there can be other reasons behind these conditions as well, but acid-base balance should not be overlooked.
As a naturopath how do I assess your acid-base picture?
There are a number of aspects to consider when taking your case history. Obviously your diet and lifestyle will be explored in detail. We will also look for signs of magnesium or calcium deficiency. A high demand for these nutrients can be a clue to an acid-base imbalance.
Another measure can be determined from your general pathology tests when your blood electrolytes are assessed. From your results we can look at your blood bicarbonate levels as well as work out something called your anion gap which can be a clue as to how hard your buffering systems are working to maintain blood pH.
A further test can measure your urinary pH. Your urine is one of the end products of your metabolism so an acidic urinary pH can be a clue to what’s happening in your body.
There are other, more sophisticated tests as well but the above assessments are a good place to start.
Where to from here?
As a starting point, think about the following. How many of them apply to you?
- a diet low in fruit and vegetables and high in animal foods, salt and processed foods
- smoking or alcohol
- regular intensive exercise
- pain or inflammation somewhere in your body
- a diagnosis of osteopenia or osteoporosis
- weight gain or blood sugar issues
- history of kidney stones or gout
- taking certain pharmaceutical medications on a regular basis
Rest assured that if you are a client of this clinic, we will be watchful for the possibility of an acid-base imbalance and will implement appropriate dietary and nutritional treatments to address your symptoms where appropriate.
*As a side note, also don’t confuse acid in the context of blood pH with “stomach acid”. The acid in our stomach (which is essential for our digestion) has a pH of around 1.5-3.5. It is highly acidic as a first line of defence against any bugs we might pick up from the food we eat and to help break food down into nutrients we can use.