The Alkaline Diet

by Registered Dietitian, Andrea Holwegner | May 12, 2014

Listen to my monthly radio program with Angela Kokott, host of Calgary Today for our segment, “You are what you eat” to get the goods on healthy eating.

 

Do some foods cause excess acid and cause disease?

So-called “experts and supplement marketers tout the alkaline diet for preventing and curing diseases such as cancer, osteoporosis, obesity, heart disease, diabetes, depression, yeast overgrowth and cellulite.

What is the alkaline diet?

The premise of the alkaline diet known as the “acid-ash hypothesis” is that our modern day diet creates a high level of acid in the body and if this acid is not neutralized it causes health issues and disease. Proponents of the alkaline diet suggest measuring your urine or salivary pH to assess your health and risk of disease. Advocates of the alkaline diet suggest consuming alkaline forming foods (veggies and fruit) and eliminating or limiting acid forming foods (meat, poultry, fish, dairy, grains, salt and sugar)

Can what we eat shift the pH of our blood?

The pH of our blood is very important and tightly regulated by our body to sustain life regardless of our food intake to maintain a pH of approximately 7.35 – 7.45. If you have a significant medical issue (such as kidney disease or diabetes) your blood pH can drop below this and metabolic acidosis occurs. You can read more about this here.

Dietary changes can only change blood pH by approximately 0.014 pH units, which has been scientifically shown not to be meaningful. Following an alkaline diet does not shift blood pH outside of the normal range.

Can what we eat shift the pH of our urine?

Research has established that the pH of our urine does change with our food intake.

In general, foods that create the most acidic urine in the body after digestion include meat, poultry, fish, dairy foods, caffeine, sugar and salt. Grains are considered slightly acid forming in the urine and legumes vary by type. Overall, the foods that create the most alkaline urine include fruits and vegetables.

When we consume acid-forming foods such as meat and dairy the body neutralizes the pH of our urine by releasing alkaline minerals into the blood. When our food is low in alkaline minerals (such as calcium, magnesium and potassium) they must come from the bone. This is one of the reasons that so much research has been done on calcium balance and bone health.

Should we be concerned?

Since the concept of measuring how different foods change urine acidity is from over 100 years ago this concept is considered overly simplistic. We now have much more current nutrition knowledge and the concept of alkaline and acidic foods and their role on health is considered outdated.

There is research to support that those that consume the highest levels of fruits and vegetables have lower risk of osteoporosis, cancer and heart disease. Eating a diet high in meat and dairy and low in fruits and veggies can acidify the urine, but research shows this does not promote bone loss or osteoporosis. Changes in urinary calcium levels are not a measure of bone health. Research also does not support the notion that dairy foods are bad for our health. Contrary to the alkaline diet there is also growing research to suggest that protein is important for bone health, especially for older adults that often consume too little.

The bottom line

While there is no scientific reason to follow the alkaline diet, the one good thing this diet emphasizes is a diet rich in vegetables and fruit. Note that while veggies and fruit are indeed healthy these are certainly not the only foods needed for health. Following a strict alkaline diet of exclusively veggies and fruit is inadequate in nutrition and will do more harm than good.

You can find a study, historical reference or ancient population to support just about anything you want to believe. What to eat is one of the most controversial, highly debated and opinionated topics on the planet. When considering any debate in health and nutrition, first look to see what the bulk of scientific data and trusted health organizations are suggesting. Next consider how the information applies to living a great life and achieving health without guilt or complexity (after all eating fully is about eating soulfully and healthfully). Life for me on an alkaline diet sounds boring, difficult to sustain and simply unsubstantiated by current science. Your thoughts?