DrAcidity and pH can be a confusing topic in health. There’s generally a consensus that an “alkaline environment” is optimal for health, but for many people who pay attention to their health, this only creates more questions.

If our bodies only function within a very narrow pH range, how is it even possible to have an acidic pH in the body? Doesn’t our body regulate it on its own? If we were all getting hyper-acidic, wouldn’t we all be dead?

And what about the stomach? Don’t we need acid there? It can’t all be about just “alkalinity.”

Let’s break this all down so we can have a clear picture of the interactions between pH, health, and diet.

What was pH, again?

Most of us have a pretty good notion of pH, but let’s just review it real quick so we’re all on the same page.

pH stands for “Power of Hydrogen”. Not the physical power hydrogen, the exponential power.

As in 2³ = 8. Two to the power of 3.

The pH scale is a logarithmic scale that goes from 1 on the acidic end to 14 on the alkaline. Each number is 10x less concentratedthan the next. 2 is 10x more acidic than 3, and so on. When you get past 7 – neutral – you increase alkalinity.

So when we talk about small changes in pH, we’re actually talking about very large differences in the acidity. Even a change of 0.1 is equivalent to a 30% change in acidity – a major impact on your sensitive biology. 

Balance in Motion: How Does The Body Maintain pH?

Since such small changes in pH have the potential to disrupt all the millions of biochemical reactions happening in our cells, the body evolved systems to keep it under ideal conditions.

In a lot of ways, it’s like your body temperature. There is an ideal set point your system maintains through very complex systems of feedback and monitoring.

Your body keeps the pH of your blood at around 7.35-7.45. If you drop down to even 7.3, you enter acidosis, which can cause headache, confusion, arrhythmia, nausea, and respiratory issues.

Small change, big consequences. Maintaining balance is critical to your health.

Your body has two primary means of regulating your body’s pH: respiration and urine.

Respiration

Every time you inhale, oxygen is transported by your red blood cells to every single cell in your body. Your cells use this oxygen as fuel, in the process creates carbon dioxide (CO₂).

The CO₂binds to the red blood cell to be transported out of the body with your exhale.

What is important here is that CO₂is acidic. It lowers the pH of your blood.

Breathing fully and deeply helps more red blood cells get rid of more CO₂ and keeps your pH right where it needs to be. If not, the CO₂ accumulates in the blood, lowering pH and stressing your system.

Urination

Urine can be either acidic or alkaline. Normally it’s slightly acidic with a pH around 6, but can range all the way from 4.5 to 8. Your kidneys work hard to filter out excess acid and keep pH stable.

The urine reflects an individual’s internal environment. The more acidic your system the more it will show in your urine. This makes it a helpful measure of a person’s pH balance.

These two pathways, urine and respiration, work together to keep your body in the tight range of biologically viable pH.

Your sleep-wake cycle is an interesting demonstration of how they work: when you sleep, your breath is shallow, so C0₂ isn’t eliminated as thoroughly. Your blood becomes more acidic. To balance it out, more acid must be filtered out through the kidneys. And if you measure it, the urine after waking is more acidic than at any other time of the day.

How the Intense Acidity of the Stomach pH Influences the Rest of the Body

So we’ve seen how the body balances pH through respiration and urine. But if the pH of the body is so highly regulated, then what about pH of the stomach?

Stomach pH fluctuates between 1 and 3.5. It is an extremely acidic environment of concentrated hydrochloric acid (HCl).

In many ways it is also a pH gatekeeper for the rest of the body. Low stomach pH has three important functions that later influence your body’s pH:

1. Breaking down food – directly and indirectly
2. Extracting minerals and vitamins
3. Killing pathogens

Breaking down food directly

Concentrated acid breaks the molecular bonds that hold your food together. Combined with the churning of the stomach muscles it helps slowly transform food matter into chyme: liquified food and digestive juices. But HCl alone would take days to fully digest your food. That’s why the low pH helps in another way to speed up the process and make digestion more efficient.

Breaking down food indirectly

Low pH activates digestive enzymes like pepsin. These enzymes specifically break down certain types of molecules like protein, fat, and fiber that are often difficult to digest. Surprisingly, this can actually impact your pH.

When partially digested food is passed into the small intestine it disrupts your microbiome. Undigested fiber and macromolecules feed the wrong kinds of microorganisms which then proliferate and crowd out the good kinds of bacteria. Yeast, bad bacteria, and other fungi create an acidic environment in your gut, leading to further downstream consequences like lower pH and inflammation.

Killing pathogens

Most organisms cannot survive pH below 3.5. This screens out many yeast, fungi, and noxious bacteria that can disturb the balance of your microbiome and lower pH.

Extracting minerals and vitamins

Many essential alkalizing minerals in our food are bound up in tight biological complexes and enzymes. Even when cell walls are broken down by enzymes, the minerals still aren’t biologically available.

With low pH, however, the minerals become dislodged and ready for absorption. Many of these minerals – magnesium, calcium, manganese, iron, and potassium – raise our pH and help keep us in homeostasis.

So you can see how low pH in the stomach sets the stage for higher pH in the rest of the body. But the converse is equally true: when the stomach pH rises, the gut becomes unbalanced, the necessary minerals for alkalization are less available, and the pH of the system lowers. 

How Food Influences pH

Now we have a good overall picture of how pH in our body works. We understand how we regulate it through urine and respiration, the influence of the microbiome, and how the stomach is the important first step to pH balance.

So how does food fit into this picture?

Different foods have different pH. Alcohol, for example is acidic. So are sugar, grain, dairy, animal protein, and most synthetic chemicals and pesticides. Vegetables and other mineral-rich foods are generally alkalizing.

But if the body’s pH is so highly regulated, how can these actually affect the pH of the body?

There are two important points to consider here.

Regulatory Mechanisms

The first is regulatory mechanisms. If you eat a lot of acidic foods and then pH test your urine, it will show a higher acidity. Now remember that each pH number is a 10x difference. If your urine pH drops one number, this means your body is working 10x harder to filter all that acid out of your system.

Filtering your blood is a biologically expensive process, so you are placing a heavier burden on your body just to maintain equilibrium. It’s like trying to walk down the street while pulling a heavy suitcase. It’s no problem for a while, but eventually you start to get tired.

Different Types of Acid

The second is the difference between organic and inorganic acids. Inorganic acids are things like stomach acid. HCl is just two small ions: one hydrogen, one chloride. Organic acids are much larger molecules made of anywhere from several to dozens of atoms.

These don’t always just get filtered out by urine.

Organic acids become sequestered into your tissues and organs. Highly toxic molecules like pesticides make their way into your cells – especially fat stores – where they not only raise cellular pH, but disrupt cellular process and cause other problems.

Consequences of an Acidic Cellular Environment

This creates a situation where your blood pH may be normal, but your tissue environment will be more acidic. Your cellular environment will be more acidic.

And an acidic tissue environment is a known breeding ground for dysfunction and disease. It impairs mental clarity. It disrupts the oxygen-burning of your mitochondria, leading to fatigue and low energy. It promotes inflammation. It can even create cancer.

The Power of pH!

Like clean water and nutritious food, a balanced pH is a foundational component of your health.

In your blood, in your body, in your gut, and especially in your stomach.

Contrary to popular belief, many digestive problems like heartburn, reflux, and GERD are caused by too little stomach acid. A higher stomach pH (less acidic) supports several negative consequences for your digestion:

• Weakens the valve between the stomach and esophagus, which then allows gastric juices into the throat.
• Hydrochloric acid is critical to extracting important vitamins and minerals from your food – Vitamin B12, folate, vitamin C, magnesium, and zinc, just to name a few. Without the acid, your body cannot get the nutrition, regardless of how much you eat.
• Inactivates the digestive enzymes you need to get nutrition from your food. With high pH over time, your body will actually stop making these important enzymes.
• Imbalances your gut microbiome, leading to even more negative health consequences