The alkaline diet is also known as the acid-alkaline diet or alkaline ash diet.
This diet is focussed on foods that affect the acidity of your body fluids.
Foods are classified as acid forming, alkali forming or neutral.
When your body extracts energy from food what is left behind is known as ash and this ash is acidic, alkaline or neutral in nature.
The nature of this ash is said to affect the pH of your body.
pH is nothing but a way to measure how alkaline or acidic a fluid is. This is how it goes:
- Acidic: 0-7 pH value
- Neutral: 7
- Alkaline: 7-14
Acidic ash can make your body vulnerable to diseases and conversely alkaline ash can help in normalizing your body.
The body has many defence mechanisms to prevent the body from turning too acidic and one such defence is the kidney.
Excess acid in the blood is filtered by the kidney and excreted in the urine.
Urine pH is a good indicator of whether your body is acidic or alkaline. A population study by the University of Cambridge revealed that a more alkaline diet comprising of high vegetable and fruit intake and low meat intake was associated with more alkaline urine.
So the basic premise is that eating a diet rich in alkaline foods can protect you from diseases.
Table of Contents
- How are the foods classified as acidic or alkaline?
- Is there any evidence regarding the efficacy of the Alkaline diet?
- What can you eat in the Alkaline diet?
- Does the Alkaline diet really affect your blood pH?
How are the foods classified as acidic or alkaline?
Based on the acid content of the food (presence of chlorine, sulphur and phosphorous) and alkali content (presence of calcium, potassium, sodium, and magnesium) foods are classified as acidic or alkaline.
- Acidic: Animal meat, seafood, alcohol, tobacco, eggs, dairy
- Neutral: Fats, sugar and starches
- Alkaline: Fruits, vegetables, nuts, legumes
Another mechanism to rate food is to determine the potential renal acid load (PRAL) which is nothing but the amount of acid excreted in your urine when you eat a particular food.
Based on this measure, you can find great details as to how alkaline or acidic a particular food is on this link.
Is there any evidence regarding the efficacy of the Alkaline diet?
There aren’t any scientific studies focussed solely on Alkaline diet and weight loss but any diet that promotes higher intake of fruits and vegetables and lowers intake of animal meat is similar to Alkaline diet for example- Mediterranean diet.
Also the reverse: Acidic diet causes obesity and metabolic disorder has been proven. So we will be going over a few studies pertaining to these issues.
Acidic diet increase the tendency to gain weight
The Western type of diet tends to increase the dietary acid load since it has low proportions of fruits and vegetables and more animal products.
This is said to contribute to the acidic condition of the body - dietary metabolic acidosis which increases with age.
To protect the body the kidney keeps excreting acidic products in the urine thus hampering kidney function and giving rise to the risk of developing uric acid stones.
However, the kidney is not alone here. A number of hormones help the kidney to excrete such acid.
One such hormone is cortisol. When acid excretion through urine increases, cortisol levels increase.
Also, a diet rich in protein and low in alkaline minerals brings about an increase in cortisol levels.
Cortisol is a major player in the development of harmful visceral fat: fat that surrounds organs and contributes to abdominal obesity and metabolic disorders like insulin resistance. Conditions like insulin resistance also lead to weight gain.
Acidogenic diets are associated with increased development of fat tissue. This is how the acid-base balance of your diet can dictate the risk of developing metabolic abnormalities, heart diseases, and obesity.
What does this mean? Acidic diet impairs kidney function leading to increased production of a hormone named cortisol which leads to accumulation of visceral fat.
Acidic diet increases insulin resistance
Insulin is the hormone, lack of which, causes diabetes. Apart from maintaining blood sugar levels, insulin also plays a role in fat metabolism.
Researchers suggest that it is not the animal protein alone in an acidic diet that can affect insulin levels but the combination of starchy foods and animal protein can impair insulin release.
Vegan diets are low in animal protein and plant protein is slowly absorbed and foods like soy protein cause release of glucagon, a hormone which promotes the breakdown of fats.
What does this mean? Acidic diets increase the tendency to develop insulin resistance. This can lead to development of type 2 diabetes and subsequent weight gain.
Alkaline diets preserve muscle mass
Protein is definitely necessary for the development of muscle mass. With increasing age, the muscle mass of our body decreases and is replaced with fat mass.
Research shows that the alkaline diet is protective against age-related muscle loss.
Scientists suggest that eating protein is necessary for muscle mass maintenance but eating fruits and vegetables and including alkaline minerals in diet is also relevant.
A 3 year study showed that only alkaline diet preserved muscle mass in older individuals but also led to an increase of percent lean body mass.
What does this mean? Alkaline diets are found to be protective against age related muscle loss.
Alkaline diet influences exercise performance
Researchers at St. Louis University have found that alkaline diets improve aerobic physical fitness of individuals in comparison to acidic diets.
Further research showed that these findings are of great importance to athletes. Shifting towards alkaline diets can improve their performance.
Another important finding is that alkaline diet can spare the burning of carbohydrates as fuel and burn fat instead.
Researchers state that alkaline diet is rich in fruits and vegetables and at the same time cuts down on fatty meats and refined grains which is why it not only has exercise performance benefits but also protects from disease.
What does this mean? Research shows that alkaline diets improve exercise performance which can translate into more weight loss.
Acid vs. Alkaline diet: Who protects bones better?
One common argument about this diet is that to balance the increased dietary acid load the bones lose their calcium and mineral content which is why it is better to adopt the alkaline diet. Loss of bone mineral content can lead to osteoporosis.
Interestingly research seems to prove the opposite. The Framingham Osteoporosis study showed that definitely alkaline diet was associated with lower loss of bone mineral density over four years but interestingly even high protein content was associated with lower bone loss.
However, we cannot ignore the fact that balance is the key; so along with proteins supplementing your diet with greens will reduce the acid load and also make your diet low in calories.
What does this mean? Recent research has proven that protein rich diets, contrary to prior beliefs, are good for bones. Overall a balance of proteins, fruits and vegetables is good for bone health.
Dietary alkaline supplements improve body’s acid-base balance
Acidic diets increase the risk of developing kidney and urinary tract related diseases by decreasing urine pH.
Results of a clinical trial suggest that consumption of a dietary supplement made of alkaline minerals like potassium, magnesium and calcium raises the blood and urine pH.
The idea to present these studies is that you can derive such minerals from fruits and vegetables and this will balance your body’s acid-base equilibrium.
What does this mean? Dietary supplements made from alkaline minerals and plant greens are proven to reduce acid levels in urine.
What can you eat in the Alkaline diet?
The alkaline diet involves increasing fruit and vegetable content in your diet and reducing animal protein.
Even citrus foods that are considered acidic are actually alkaline foods since their ash is alkaline in nature.
You can include the following foods to make your diet more alkaline:
- Alkalizing vegetables: Kale, spinach, broccoli, celery, cucumber, beetroot etc.
- Alkalizing fruits: Apple, orange, peach, banana, berries, watermelon
- Alkalizing proteins: Nuts and soybean
Does the Alkaline diet really affect your blood pH?
The blood pH is around 7.35 and 7.45. It is very important for our blood pH to remain constant and our body takes the necessary steps to maintain this.
Metabolic acidosis is a condition when the body produces excess acid or the kidney fails to remove excess acid.
It is very unlikely that foods in the quantities that we consume could affect the blood pH. In this paper , it is revealed that amounts as large as 18 pounds of orange or 4.5 pounds of lean beef at a time would be required to shift the pH of the blood.
Alkaline diet influences urine pH but is not likely to affect blood pH.
Nevertheless increasing fruit and vegetable intake in alkaline diet will benefit bone health and reduce chronic diseases like aches, hypertension etc.
An alkaline diet like most other diets focuses on eating healthy, organic food and is sort of in line with the vegetarian diet. It does not bring anything new to the table.
Foods included in this diet such as leafy greens and fruits are definitely going to make you lose weight since they are low in calories and also improve your health.
Since there is not much scientific evidence available about this diet, many clinicians don’t recommend it.
The alkaline diet is healthy since it is rich in organic foods.
Whether it affects blood pH is still a matter of debate. If you are thinking of a detox or lifestyle change, we would recommend the Alkaline diet.