More and more people are paying attention to the pH levels in their bodies and the level of acidity in their foods.
For people with certain kidney and digestive issues, avoiding acidic foods can be part of maintaining their health and feeling good.
But, if you watch the number of acidic foods in your diet, you may wonder – are eggs acidic or alkaline?
The truth is an egg’s pH level changes over time. When an egg is laid, it is almost pH neutral, averaging about 6.6 for the whole egg.
A freshly laid egg has an egg yolk with a pH level of about 6.0 and an egg white with a pH of about 7.6.
Over time, an egg becomes more alkaline, with an egg white that can reach 9.2 and an egg yolk that reaches 6.9 pH.
The process of becoming more alkaline depends on the temperature at which the egg is stored: A colder egg does not become alkaline as quickly.
The acidity or alkalinity depends on which part of the egg, the age of the egg, and how it has been stored and prepared. There’s no simple answer for all eggs all the time.
As you can see, the answer isn’t as straightforward as it seems, so let’s learn more about whether eggs are acidic or basic.
Are Eggs Considered Acidic or Alkaline?
Eggs, as a whole, are considered pH neutral, but they do become more alkaline over time.
In a whole egg, the slightly acidic egg yolk is balanced by the more alkaline egg white, especially when it is fresh.
As the egg white becomes more alkaline over time, an older egg is more alkaline overall.
Are Eggs Acidic or Alkaline After Digestion?
After foods are digested, it’s difficult to separate and measure the pH level of eggs individually.
Because the body has a neutral pH, but the pH levels of the stomach vary dramatically during digestion, it’s also difficult to measure specific alkalinity or acidity of foods during the digestive process.
Finally, it’s important to remember that our foods’ pH levels do not affect our bodies’ pH levels: our lungs and kidneys regulate the pH levels of our blood, keeping it at the 7.4 necessary for survival.
When scientists measure the acidity and alkalinity of foods and their effect on the body, they aren’t measuring the pH levels of the food or the blood.
Instead, scientists assess a factor called the “potential renal acid load,” or PRAL.
The PRAL of a food indicates how much effort will be required by the kidneys to eliminate the excess acid and maintain the natural pH level in the body.
PRAL is calculated by considering:
- The chemical composition of foods. Each food contains protein, sodium, calcium, chloride, etc.
- The absorption rates of nutrients. The intestines absorb different nutrients at different rates, so they enter the bloodstream at different times.
- The breakdown of nutrient-specific compounds. As sulfur-containing amino acids break down in the body, they generate sulfate, which can be measured. Likewise, the ionic valence of calcium and magnesium can be measured, and the dissociation of phosphorus
- Daily net acid excretion. Healthy adults excrete a relatively constant amount of organic acids every day
All these factors allow scientists to calculate and estimate the potential renal impact of the acids in foods, arriving at the PRAL score.
The amount of protein in a food is a crucial driver of PRAL scores, and foods that are high in protein will almost always have an acidic PRAL score to some degree.
For people with delicate kidneys and other medical conditions, it may be important to consider the PRAL measure of a food to reduce stress on the kidney.
The PRAL level of a food is highly divergent from the pH level of a food.
For example, lemon juice is highly acidic, with a pH between 2-3. However, lemon juice has a negative PRAL score of -2.5 and has an alkalizing effect on the body when metabolized.
Unlike pH, the PRAL score of a food also depends significantly on how the food is prepared.
For example, a fried egg has a higher PRAL score than a poached egg. Likewise, dried egg whites have a higher PRAL score than fresh egg whites, and so on.
Is Egg White Acidic?
Egg whites have a high pH from 7.5-9, indicating that they are alkaline.
However, they also have a relatively low positive PRAL score of 2-3, meaning that egg whites are mildly acidic in the body.
Egg whites are also a special case where we often whip them into a foam or meringue.
Egg whites with a pH closest to 7.0 whip into the most stable foam.
Because egg whites have an increasing pH as they age, people often add cream of tartar (a mild acid) to egg whites to stabilize them as they whip them for better foams and meringues.
Is Egg Yolk Acidic?
Egg yolks have a pH level from 6-7, making them mildly acidic.
Egg yolks also have a high PRAL score of 23.4, indicating that they have a higher impact on the kidneys.
Are Boiled Eggs Acidic?
Some people boil their eggs in vinegar, which makes them more acidic.
When eggs are boiled in plain or salted water, they start with a neutral pH of 7.0.
Over a week, eggs boiled in salt will become more acidic as the pH drops to just over 4.0.
Unsalted boiled eggs that are vacuum sealed and kept cold maintain a pH of 7 or more as they age.
Hard-boiled eggs have a PRAL value of 9.
Are Scrambled Eggs Acidic?
Scrambled eggs have a neutral pH of about 7.0. Scrambled eggs have a PRAL value of 7.5.
The acidity level of scrambled eggs may also be affected by whether they’re cooked in butter or oil.
Are Alkaline Diets Worth It?
More and more people are claiming incredible health benefits from alkaline diets, but little scientific evidence supports these health claims.
In fact, because the body regulates its own pH levels, regardless of the foods you eat, the acidity or alkalinity of your foods does not dramatically impact the body.
Some foods have a more significant effect on the kidneys as they balance pH levels in the blood.
A vast range of factors need to be accounted for when considering the potential impact of different foods on the kidneys, but the protein level, not the pH level, plays a pivotal role.
When doctors and scientists estimate the impact of foods on the kidneys, they calculate the PRAL score, which measures how much work the kidneys must do to maintain the optimal pH level in your blood.
However, this PRAL value is not related to the pH value of foods and is measured very differently.
In fact, very alkaline foods may have an acidic effect on the body and vice versa.
Doctors may recommend a low-PRAL diet for kidney patients and people with certain health conditions.
However, for people without special health needs, there is no reason to worry about the PRAL levels of your foods because the kidney naturally and effectively regulates the pH level of your blood by excreting excess acidic or alkaline compounds.
When people claim to be experiencing health benefits from an alkaline diet, it may simply be that such a diet is high in fruits and vegetables, as are all healthy diets.
Because egg yolks are mildly acidic and egg whites are mildly alkaline, whole eggs have a neutral pH, especially when fresh. Fresh eggs that are freshly cooked also have a fairly neutral pH.
Over time, raw eggs become more alkaline as they age, while cooked eggs tend to become more acidic when stored.
To avoid the most acidifying aspects of eggs, eat the egg whites only and avoid the yolks, or eat eggs with low-PRAL foods (like dried herbs, mushrooms, tomatoes, or fresh greens) to balance the meal.