Ask Ali Zentner, a specialist in internal medicine and obesity and medical director of the Revolution Medical Clinic in Vancouver, about the persistent popularity of the alkaline diet and, at first, she laughs. “It’s ridiculous,” she says. Then she gets angry. “It’s just the resurfacing of another ‘diet of the day’ and it’s a symptom of a bigger issue. Diets are like a religion—people latch on to one and feel theirs is the best, even though there’s no data to support it.”
In the case of the alkaline diet, not only is there no data to support it as a healthy way to lose weight, she says, but it’s just one more in a long list of fad diets destined to leave people feeling frustrated and as though they’ve failed.
What is the alkaline diet?
The alkaline diet first surfaced in the early 2000s when Robert Young (a wellness guru who was sent to jail in 2017 for practising medicine without a license and has faced several lawsuits from former cancer patients who he “treated”) published a series of books, including The pH Miracle: Balance Your Diet, Reclaim Your Health. Despite the fact Young has been soundly discredited, the idea that the body is too acidic and can be fixed with alkaline foods caught on fast—and stuck.
Andrea D’Ambrosio gets asked about the alkaline diet all the time. “Like any fad diet, people are always intrigued by the promise of fast and easy weight loss,”says the registered dietitian and owner of Dietetic Directions in Kitchener, Ont. “The alkaline diet also grabs people’s attention with celebrity endorsements.” (Kate Hudson, Elle Macpherson, Victoria Beckham and, of course, Gwyneth Paltrow, have all raved about it.)
The alkaline diet is based on the premise that so-called “acid-producing” foods such as meat, fish, dairy products, sugar, caffeine and grains make the body too acidic, which can lead to weight gain, diabetes, cancer and heart disease. “The theory is that by cutting out ‘acidic’ foods and increasing the intake of ‘alkaline’ (or basic) foods like fruits and vegetables, you can restore the body’s equilibrium and improve energy and weight loss, as well as prevent chronic diseases,” D’Ambrosio says. But, none of this is borne out of scientific study.
How can whole grains and milk be considered acidic?
Proponents claim that when certain foods (meat, grains, diary, etc.) are broken down, they produce a metabolic waste or “ash” that can be either alkaline or acidic. Acidic ash (caused by so-called acidic foods) make your blood acidic and more vulnerable to disease. But it bears repeating that this is made-up pseudoscience.
Is your body too acidic?
Your body is constantly working to maintain a normal pH (a measurement of how acid or alkaline something is) of between 7.35 and 7.45 in the blood, which is slightly alkaline, Zentner says. “You need that balance to function—pH is to the body what temperature is to the planet.”
The two organs responsible for maintaining that delicate balance between alkalinity and acidity are the kidneys (by retaining or excreting hydrogen and bicarbonate, depending on what our body needs) and the lungs (by getting rid of carbon dioxide). “If you think back to high school chemistry, the more hydrogens in something, the more acidic it is, the more bicarbonate, the more basic,” Zentner says.
But can what we eat alter the pH levels in our bodies? Not in our blood or in our cells, where it matters, D’Ambrosio says. “The fact that certain foods might change the pH of your urine slightly isn’t a reliable indicator for health outcomes, it’s a sign that your kidneys are efficiently excreting waste to maintain your body’s equilibrium.”
What about alkaline water?
Some parts of the body have a different pH, like the stomach, which has a pH of 2. “Stomach acid could burn a hole through a table,” Zentner says. Which means that, when it comes to eating more alkaline foods or chugging alkaline water, you’re just wasting your time—and your money. “Alkaline water might be alkaline in the bottle, but it’s not going to be alkaline once it hits your stomach.”
Zentner also questions why anyone would want to make it harder for their body to do its job. “It’s not possible to change the pH of your body with food and even if you could, it certainly wouldn’t be healthy.” In fact, alkalosis—when your body is too alkaline—is actually a condition that can cause nausea, vomiting, light-headedness, confusion and muscle spasms. There are two types: respiratory alkalosis (which can occur when there is too little carbon dioxide in the blood due to things like hyperventilation or being at a high altitude) and metabolic alkalosis (which can occur when the body loses too much acid due to poor kidney function).
Is there anything good about the alkaline diet?
Medically speaking, the alkaline diet is unlikely to do you any serious physical harm, Zentner says. “However, it takes an emotional toll when it doesn’t work.”
D’Ambrosio adds that strict adherence to the alkaline diet could lead to a lack of essential vitamins, minerals and fibre. “Completely avoiding so many otherwise healthy foods (fish, eggs, meat, dairy, whole grains) means you may not be receiving balanced nutrition,” she says. “Plus, the idea of severely restricting a diet based on unreliable science is troublesome.”
Still, she adds that the one good thing about the alkaline diet is that it encourages people to eat fewer processed foods and more fruits and veggies. “The typical ‘Western diet’ tends to be high in processed foods and meats and low in fruit and vegetables,” she says. “And increasing fruit and vegetable consumption helps boost potassium and magnesium intake, which can protect you from high blood pressure and stroke.” While eating an alkaline diet itself isn’t going to help you maintain a healthy weight or protect you from disease, eating a balanced diet with lots of fruit and vegetables just might. In fact, the healthiest way to approach your diet is to think about what nutritious foods you can add, not what “forbidden” foods you have to give up.
Posted June 2019. Updated January 2021.