The alkaline diet has a number of proposed health benefits including improved heart and brain function and reduced risk of type two diabetes. It has also been claimed to halt cancer growth. But what does the science actually say? Are these proposed benefits merely just bitter sweet?

What is the Alkaline Diet?

The alkaline diet was devised on the premise that what you eat can alter the pH (i.e. the acidity) of your blood and body’s tissues.

Its advocates say that too much acidity in the body can lead to poor health and disease. With this assumption, eating fewer acidic foods and more alkaline foods will help us achieve an optimal internal pH and better overall health.

What Foods are Acidic?

Acid-forming foods include:

  • Alcohol
  • Beef, pork, lamb
  • Cheese
  • Chicken, turkey
  • Chocolate
  • Coffee
  • Milk
  • Peanuts
  • Shellfish
  • Soft drinks
  • Walnuts
  • White flour
  • White sugar

The Alkaline Diet: Acid-forming foods

What Foods are Alkaline?

Alkaline-forming foods include:

  • Almonds
  • Amaranth
  • Apples
  • Asparagus
  • Avocado
  • Banana
  • Broccoli
  • Carrot
  • Garlic
  • Kale sprouts
  • Mushroom
  • Olive oil
  • Onions
  • Pears
  • Pineapple
  • Quinoa
  • Sweet potato
  • Wild rice
  • Zucchini

The Alkaline Diet: Alkaline-forming foods

Sounds great. But let’s dig a bit deeper and see what the science says.

Science and The pH Scale: 

The pH scale measures how acidic or basic a substance is (or in this case, food). A pH of 0 indicates a high level of acidity whereas a pH of 14 indicates a high level of alkalinity (or basic).  

On the scale, a score of 0 up to 7 represents an acidic compound; 7.0 is neutral and a score of 7.1 up to 14 represents a basic (or alkaline) compound.

Does Food Change the pH of our Body?

According to the Alkaline Diet, acid-forming foods cause a build-up of acidic compounds in our body tissues and bloodstream, which can causes serval adverse health conditions. However, this theory assumes that our body’s pH is largely driven by the food we eat, which is not supported by science.

While it is true that the digestion of food creates acidic and basic compounds, the acidity and alkalinity of foods actually has minimal effects our blood’s pH! This is because our body is equipped with buffering systems which keeps our blood pH slightly alkaline between 7.35 and 7.45.

The acidity and alkalinity of foods actually has minimal effects our blood’s pH! This is because our body is equipped with buffering systems which keeps our blood pH slightly alkaline.

One of the ways our body keeps our blood pH within this slim margin is through the help of our kidney and lungs whose role it is to orchestrate what is eliminated and in what amounts. This regulation is largely maintained through the elimination of urine, saliva, sweat and even gasses through our breath.

If our blood pH deviates out of this range, our body can go into acidosis or alkalosis, which can result in coma or death.

Hence what we eat does not alter the pH of our blood due to our body’s inbuilt systems.

So is the Alkaline Diet Bad for your Health?

No. In fact, the foods you’re ‘allowed’ to eat on the alkaline diet are actually very good for you! Lots of fruit and vegetables, lots of water, limiting added sugar, cutting back on alcohol, and reducing intake of processed foods. No wonder people claim the diet to improve their health and wellbeing!

The alkaline diet basically reinforces many aspects of healthy eating. Increasing your intake of vegetables, fruits, legumes, wholegrains and drinking lots of water inevitably improves your health – just not for the reasons proponents of the diet claim. It’s as basic as that!

A Word of Caution:

Considering that an alkaline diet consists largely of plant foods and limits processed foods and alcohol, it is no surprise that people feel better on it. Unfortunately, however, claims have been made about the alkaline diet improving health outcomes of disease states, such as cancer. This is not only false, but can be damaging for those involved. Further research on this area is required.

Again, optimisation of health and improved outcomes may be related to the fact that the alkaline diet is built around fruits, vegetables, and legumes; three dietary components linked to improved health and disease outcomes.

Want to find out what the science says about other diets? Click here to learn about the Ketogenic Diet and here to learn about Detox Diets.

Article co-written by student Dietitian & Nutritionist Alice Bleathman from the Nourish Naturally team.