Investigating The Alkaline Diet: Does It Really Move The Needle On Health?

If you've ever heard an influencer or celebrity say that they eat "alkaline foods," it probably made you scratch your head. Supporters of an alkaline diet claim it can enhance overall health, improve energy levels, and even prevent chronic diseases like cancer—but this sure sounds too good to be true.

Supporters of the alkaline diet make some big claims: They claim that eating alkaline foods may improve bone health, weight management, and cancer risk reduction. 

There's not enough research to support the alkaline diet: Most of the benefits of this diet probably come down to the fact that most alkaline foods are whole, plant-based ingredients. But they don't change your blood pH in any meaningful way.

Different foods have different levels of acidity. Foods that are highly acidic are called “acidic” foods, and those that are not acidic at all are called “alkaline.” Some refer to alkaline foods as basic.

The acidity or alkalinity of foods are measured by their pH, and it is measured on a scale of 0 to 14. Foods that are considered acidic, like vinegar, alcohol, and citrus foods, have a pH of less than 7. And on the flipside, alkaline foods have a pH higher than 7. 

Foods with a pH value of 7 are usually classified as neutral. This means they neither contribute to acidity nor alkalinity in the body. An example of such food is distilled water, which is considered the standard for the pH scale. 

The alkaline diet, also known as the acid-alkaline diet or alkaline ash diet, revolves around the idea of optimizing the body's pH level. Proponents claim that by replacing acid-forming foods with alkaline foods, you can improve your health and prevent various diseases. 

Although the alkaline diet has gained some traction over the years, the medical community is not a fan of it. This is because there isn’t enough evidence that suggests eating this way actually offers any benefits.

“For healthy people, your body will keep your blood pH in tight balance, even if you don't follow an alkaline diet,” explains nutritionist Jen Scheinman, MS, RDN. “Your lungs and kidneys work 24/7 to ensure that your blood pH is tightly regulated, no matter what foods you eat," she added. 

When looking at the kidney’s role in the pH-balance story, this organ helps manage the body's pH balance by regulating sodium bicarbonate, a compound which is alkaline in nature and helps neutralize acid. When the body becomes too acidic, the kidneys are able to impact the level of sodium bicarbonate in the body to prevent the it from entering a severely acidic state.

In addition to the kidneys, the lungs also play a pivotal role in maintaining the body's pH balance. This is achieved through the process of respiration—inhaling oxygen and exhaling carbon dioxide, which is an acid. When the body's pH balance veers towards acidity, the rate of respiration increases, leading to a higher expulsion of carbon dioxide and, consequently, lowering the acidity in the body. 

Some parts of the body are also naturally more acidic than others—and that's a good thing. Your stomach, for example, provides a highly acidic environment1 to break down foods, while your skin is mildly acidic to keep surrounding bacteria out.

One study suggested that, although eating foods that are alkaline may support bone health, intervention studies with a more alkaline diet have not consistently shown a bone health benefit2. An increase in dietary intake of fruits and vegetables (like those in an alkaline diet) could benefit bone health1, though. There is some data suggesting that following an alkaline diet may offer some benefit for people using chemotherapy1, but more data is needed.

If there's no good research to support this diet, why are some people so in favor of it? Well, it is true that being in an acidic state can be dangerous. Having increased acidity in the blood (acidosis3) can lead to the leaching of calcium from our bones, as the body uses this mineral to neutralize the excess acidity, thereby increasing the risk of osteoporosis. An acidic environment in the body can impair the immune system's functionality and have a negative impact on muscle health4. 

But as long as your kidneys and lungs are functioning properly, your body should not enter the extreme state of acidosis, regardless of what you are eating. 

Some of the benefits people experience when they follow the alkaline diet may be more due to the fact that this diet encourages the consumption of nutrient-dense foods.

The idea behind the alkaline diet is fundamentally flawed: Our bodies do a good job of keeping our blood pH in check5 on their own, and the foods we eat don't make much of a difference.

Not to mention, counting the pH of your foods is an unnecessary headache for most people. It may increase your stress levels at best and contribute to disordered eating at worst.

Instead of worrying about whether the foods you're eating have an acidic or alkaline effect on the body, just do your best to consume a diet rich in fruits and vegetables. Eating a whole-food, plant-heavy diet can have a positive impact on your blood sugar6, immunity7, brain health8, and more.

Despite the lack of scientific consensus supporting the alkaline diet, some people may still benefit from limiting highly acidic foods.

Individuals with gastroesophageal reflux disease (GERD), stomach ulcers, or erosive gastritis often find that certain foods can exacerbate their symptoms. For these people, an overly acidic diet may cause discomfort and further irritate the stomach lining or esophagus.9

Foods and beverages such as citrus fruits, spicy food, coffee, alcohol, and tomato-based products are also known to increase the acidity in the stomach, which could trigger GERD symptoms like heartburn and regurgitation.

Similarly, people with stomach ulcers or erosive gastritis may find that acidic foods aggravate their condition, causing symptoms such as stomach pain, bloating, nausea, or vomiting.

In these instances, a diet that limits these foods and focuses more on alkaline or neutral foods like green vegetables, bananas, and lean proteins may help mitigate symptoms.

People with kidney disease may also need to exercise caution with highly acidic foods and may benefit from an alkaline diet10. The kidneys' role in maintaining the body's pH balance means they can be negatively affected by an overly acidic diet. 

The alkaline diet is rich in nutrient-dense foods that can support many aspects of our health. And being in an acidic state can pose health risks, like an increased risk of osteoporosis. But for many healthy people, the foods we eat do not impact the pH of our body long-term, as your lungs and kidneys can help neutralize an acidic state naturally. Many acidic foods are nutrient-dense too, and eliminating or severely limiting them will not support overall health.