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Alkaline Diet for Osteoporosis: Yes or No?

You want to strengthen your bones, but you want to do it naturally. You may have heard that eating alkaline foods is better for your bones. 

In this article I will delve into exactly what an alkaline diet means. You will learn how we know which foods are alkaline. 

You will learn some pros and cons to following a strict alkaline diet. 

Let’s start now.

Acid, Alkaline and Your Bones

What is pH?

Let’s start by defining pH, a measure of how acidic or basic a substance is. Basic is the same thing as alkaline. 

The pH scale goes from 0 to 14. Substances with a pH below 7.0 get more acidic as they decrease. Very strong acids like the hydrochloric acid found in your stomach have a pH of around 1.5.

A pH of 7 is neutral, and above 7 becomes more alkaline. Most of the fluids in your body have an alkaline pH somewhere between 7.35 and 7.45.

A substance has to be fluid and water-based in order to measure pH.

The H in pH stands for hydrogen. It is the amount of free-floating hydrogen atoms in the fluid that determines the pH. The letter “p” stands for power. A Danish scientist named Sorenson came up with this name back in 1909.

The easiest fluid to measure is urine, which can range from an alkaline to an acidic pH. One of the jobs of urine is to balance out your pH, and excrete extra acid or base.

How Does Your Body Regulate pH?

Everyday you are exposed to substances that are either acid or alkaline. This happens through the foods you eat, products that come into contact with your skin, and air that you breathe. How does your body keep the narrow range of pH that it needs?

When your pH begins to drop, you have several different ways to bring it back. 

The respiratory system regulates your pH by releasing carbon dioxide into the air. The kidneys regulate pH by excreting or reabsorbing different minerals and hydrogen ions.

History of the Alkaline Diet

The alkaline diet has its origins in the study of kidney disease. As I mentioned earlier, the kidneys are important for keeping a balanced pH. 

People with chronic kidney disease have trouble getting rid of acid. One of the ways to manage this condition is by eating an alkaline diet with many fruits and vegetables (3).   

The research on kidney disease has been extrapolated over to a population whose kidneys are not damaged. It isn’t clear that eating a strict alkaline diet has the same benefits for people without kidney disease.

Does Food Affect Your Body pH?

Many things affect whether your fluids are acid or alkaline. These include advancing age, physical exercise, BMI, certain medications and how much salt you eat. The foods you eat might also play a small part in maintaining your pH.

Nearly all foods contain substances that break down into acids in your body. However plant-based foods also contain alkaline minerals like potassium, magnesium and calcium. These can help to neutralize those acids (4).    

Which Foods are Alkaline?

The pH of a food itself does not determine whether it is acid or alkaline. For instance if you measured the pH of an orange you would find it is acidic. However, oranges are an alkaline food.

It is the way your body metabolizes the food that makes it acid or alkaline. Your body breaks foods down into their smallest chemical components, which include minerals like calcium, potassium, chloride and sulfur. These minerals affect the pH of your body fluids.

The PRAL List

The residue that is left when a food is metabolized is called the “ash.” This is what determines the acidity or alkalinity of that food. One way to measure this is the Potential Renal Acid Load (PRAL). PRAL is a somewhat complicated formula that measures the amount of acid or base produced when a certain food is digested and metabolized.

The USDA publishes a comprehensive PRAL list. All the values are based on a standard 100 grams of food. Negative PRAL numbers are alkaline foods, 0 is for neutral foods, and positive numbers are acidic foods. Note that this is the opposite of the way the pH scale works.

Here is a summary of some PRAL scores.

Negative (alkaline) PRAL foods include:

  • most vegetables
  • most fruits
  • spices
  • beans
  • legumes
  • herbal teas
  • quinoa
  • goat milk
  • seaweed

Fish oil and cod liver oil have a PRAL of 0, which is neutral.

Positive (acidic) PRAL foods include:

  • cream
  • milk
  • yogurt
  • ice cream
  • grains such as oats, buckwheat, rice or wheat
  • butter
  • baked goods
  • candy
  • fish and shellfish
  • eggs
  • meats
  • fried foods

All of these foods lie on a scale. So, things like yogurt and oats will only be slightly acidic, while meats are much more acidic. 

There is a LOT of discrepancy in different lists for alkaline foods. For instance some lists say oats are neutral. Some say they are acidic, and some say they are an alkaline food. It is best to get your information from a well-researched reference such as the USDA PRAL database.

You can see some excerpts from the USDA PRAL database here and here.

Read on to find out why I don’t really want you to be checking everything you eat against a PRAL list.

Where Does Your Bone Come Into the Picture?

Another way the body regulates pH is by mobilizing a tiny amount of calcium from bone. Calcium can neutralize acid in your blood, and bring it back to a normal pH.

A healthy person can easily manage shifts in pH. Their lungs and kidneys are up to the task of returning the body to an alkaline state. It is when there is chronic, low-grade acidosis that you might begin to draw minerals from your bone (1).

As you get older, your kidneys are less efficient at reabsorbing the alkaline minerals. This makes it harder to maintain an alkaline pH. It may be one explanation for bone loss in older people (2).

The pH of your body fluids affects your bones in other ways. When your pH drops below 7.4, osteoclasts become more active. These are the cells that dissolve bone tissue. Mineralization of bones is inhibited below a pH of 7.4.

Once the pH rises into an alkaline level above 7.4, osteoblasts can get to work. These are the cells that create new bone tissue. Mineralization happens at an alkaline pH (1).


Should You Eat An Alkaline Diet For Osteoporosis?

You should know that science has not yet established that eating alkaline foods can improve bone health. There are many studies that support theories on both sides of the argument for an alkaline diet (1) (4).  Let’s look at the pros and cons of the strict alkaline diet for bone health.

Pros of Alkaline Diet for Bone Health

Alkaline foods influence the acidity of your urine. They can offset the effects of the acidic foods that you must eat to get protein.

The Alkaline Diet is loaded with fruits and vegetables. These provide many other benefits besides their alkalinity.  Fruits and vegetables contain fiber, antioxidants, anti-inflammatory chemicals, and essential vitamins and minerals. 

Many of the nutrients you need for healthy bones come from plants. Your microbiome also thrives on a variety of plant-based fibers.

For older women, eating more alkaline foods may also help you to preserve muscle mass, according to the research (5).  

Cons of Alkaline Diet for Bone Health

Following a strict alkaline diet limits large groups of foods that provide specific nutrients. You are NOT supposed to eat only alkaline foods. It should be a balance of 60 to 40, or 75 to 25. However, people on this diet are naturally going to limit the foods on the acid side of the scale.

Comparing everything you eat to a chart and calculating numbers can send you down a slippery slope to a restrictive diet. 

Meat, eggs and dairy products provide nutrients like bioavailable protein, zinc and vitamin B12. Your bones and other organs need these nutrients. You might not get enough when you put these foods on the “bad” side of the scale.

The amount of protein recommended in an alkaline diet is below what I would recommend for optimal bone health. Remember, your bones contain a lot of protein.

The alkaline diet recommends you eat the RDA of 0.8 g/kg/ day of protein, and sometimes even less. Research shows that protein intake above the RDA of 0.8 g/kg/day can help to prevent bone loss and decrease risk of hip fracture (6).  

There is a strong link between maintaining bone and muscle as you get older. Protein is an important nutrient for both of these things. A study in 2019 showed that protein amounts up to 1.5 g/kg/day (along with exercise and vitamin D supplementation) had a significant effect on skeletal muscle mass index and hand grip strength. This study was done with men aged 73-91 years (7).  

An older adult without sarcopenia or kidney disease should eat between 1.0 and 1.5 g/kg/ day of protein. For a person weighing 150 pounds, this amounts to 70 to 100 grams of protein each day.

The important thing is to balance that protein out with lots of fruits and vegetables.

So What Is The Best Diet For Bones?

Animal products provide the most bioavailable sources of protein, iron, zinc, copper and other minerals that are important for bones. You can limit red meats to once or twice a week. But make sure to eat proteins like fish, poultry and dairy products on the other days.

Balance that out with plant proteins. Good sources of plant protein include beans and legumes, peas, oats, quinoa, amaranth, nuts and seeds, and spirulina.

Eat at least 5 servings of vegetables each day, and a couple servings of fruits. Slowly work on increasing this to an even higher amount.

Avoid processed foods, fried foods, refined flours, sugary foods, excessive caffeine and alcohol.

Does planning a bone-healthy diet and putting it into practice seem a daunting task? I can help with that! Give me a call and let’s talk about it.

Final Thoughts

Your body keeps blood at a very narrow pH between 7.35 and 7.45, which is alkaline. Your lungs and kidneys shoulder most of the work to maintain that pH.

We have learned that following an alkaline diet can be beneficial for people with kidney disease. This has carried over into the general population. However, there is not a lot of evidence that following a strict alkaline diet benefits someone who is already healthy.

The PRAL score can tell us whether a food is acid or alkaline.

A third way that your body neutralizes acid is by taking a small amount of calcium from the bone. If you have a chronic, low-level state of acidosis, this might have an impact on your bone density.

An acidic pH also activates the osteoclasts that break down bone. An alkaline pH triggers the process of mineralizing your bone.

There are pros and cons to following a strict alkaline diet. In the end, a more modified version might be healthier for your bones. You may need to eat a bit more protein than the alkaline diet recommends. You will still eat a large variety of fruits and vegetables. 

Are you looking for more guidance on exactly what foods are best for your bones? For a limited time, join my FREE 5-Day Adventure to Build Better Bones.

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