5.1 Alkaline Diets

There’s no doubt that the “alkaline diet” is one of the most contentious approaches to using nutrition to support and maintain health. The reason that this dietary approach is either lauded or dismissed, depending on your point of view, is that there seems to be so little scientific evidence presented. It’s a dietary approach that has been used for many years by traditional health practitioners but often with observational rather than clinical evidence to back up its health benefits in optimising cellular pH homeodynamics and managing low grade metabolic acidosis and all the associated health problems that we discussed in Part 1, Module 4. Please remind yourself about the importance of cellular pH to health through referring back to your notes on Part 1 Module 4.1; you can also read the first couple of pages of the nutrihub education article “The Importance of Balancing Body pH”.

So what is the link between low grade metabolic acidosis and the alkaline diet? And can we really influence body pH and through the diet? The answer is yes! Importantly, however, we now know why. In the last few years, research has finally helped us understand how certain foods impact the body’s electrolyte balance and therefore influence body pH. This has helped clear up any confusion from the traditional approach to understanding dietary impact of body pH, i.e. eating foods with acid pH will increase acidity in the body and those with alkaline pH provide alkalinity. We now know it’s a little more complex than that (as is so often the case when looking at the complexities of the human body!) – our sponsor Nutrigold has helpfully summarised the findings relating the “Potential Renal Acid Load” of food (i.e. PRAL score that measure the alkaline load of different foods) and its impact on cellular pH. Please read the following blog which forms part of the course content:

Do Alkaline Diets Really Work?

Please also read the rest of the nutrihub education article “The Importance of Balancing Body pH”.

There is also a useful USDA table listing foods with low PRAL scores (i.e. those foods that have high alkaline load) and high PRAL scores (i.e. those foods that have low levels of alkalinity). Please view the table accessed by the link below; you may like to work out the PRAL score of the meals you ate yesterday:

USDA PRAL list

But, where does this leave the practical application of alkaline diets? Well, we believe it’s important to know the impact that high and low alkaline load foods can have in the body and why this affects body pH and has the potential to influence low grade metabolic acidosis. However, we also agree that providing people with a long list of food PRAL scores and telling them to work out what to eat for better health is not particularly practical!

This is where common sense comes in – if you look at the USDA PRAL list you will see that vegetables, legumes, spices, herbs, nuts and fruits tend to have negative PRAL scores, i.e. they have a high alkaline load. Dairy, grains, meats and processed foods all have positive PRAL scores of varying degree indicating low alkaline load. This therefore places vegetables, once again, as the important main player in influencing our health. In this instance for providing high levels of alkalinity; in Part 1 we discussed the importance of vegetable fibre content, and in subsequent Part 2 modules we will also explore this food groups superior phytonutrient, vitamin and mineral content and the benefits these provide to health.

So to summarise the alkaline diet approach:

1. Low grade subclinical metabolic acidosis is a chronic state that is influenced by diet and the environment.
2. Imbalances in body pH can underpin several different disease states including osteoporosis and chronic inflammation.
3. Vegetables should make up the majority part of the daily diet to provide high levels of alkalinity and offset foods with positive PRAL scores including meat and dairy.

We therefore may not always suggest that people implement an “alkaline diet” by name but the very inference of increasing daily vegetable (and plant matter) intake and reducing processed and sugary foods is promoting the management of subclinical acidosis in the body.

This table summarises the benefits and disadvantages of an alkaline diet.