You hear about the alkaline diet a lot — from health coaches, celebrities, and even some doctors will offer information about alkaline foods. So what is an alkaline diet, and is there any evidence that it's helpful?

The alkaline diet theory

The idea behind an alkaline diet is that you can help your body maintain a healthy blood pH through the food you eat. A pH of 7 is considered neutral; anything below that is progressively acidic, and anything above it is progressively alkaline. Not surprisingly, stomach pH is generally acidic while the blood hovers between a pH of 7.35 and 7.45, and your urine changes pH depending on your diet.

Unless you have a serious and specific health issue, your kidneys regulate your pH level regardless of what you eat, but supporters of the alkaline diet stress that eating in a way that promotes alkalinity is less stressful to the body, and they believe it helps make both our urine and blood more alkaline. 

Alkaline foods

“Alkaline foods” include the majority of vegetables and fruits, such as broccoli, cabbage, berries, kale, green beans, lettuce greens, cucumbers, peppers, apples, beets and more. When eaten raw, citrus has an acidic pH, but it also has an alkaline "ash," and so is considered an alkaline food. If that sentence made you do a double-take, here's the explanation: A key theory behind the alkaline diet is that foods leave an ash, or residue, after we've consumed them. Some foods — such as meat, *grains, coffee or eggs — leave an acidic residue while other foods, such as fruits and vegetables, leave an alkaline residue. (*There are different views about specific grains, including some gluten-free grains such as millet and some roots. Some consider them acid-forming while others say they are alkaline-forming; there isn't across the broad consensus on which ash they produce.)

Is it healthy?

An alkaline diet may be healthy, according to the Journal of Environmental and Public Health (JEPH), but perhaps not for the reason that proponents of the diet would have you believe. Many of the alkaline foods have been studied and found to be good for health in many ways. Broccoli has certain cancer-fighting properties, blueberries protect our brains, and kale is full of antioxidants and nutrients. There's plenty of evidence that a produce-filled diet is a good diet for many reasons: for weight control or weight loss, for fighting cancer, for getting proper nutrition, and for keeping blood sugar levels stable.

However, the alkaline diet views some foods, such as dairy, whole grains, or meats as “bad" — yet those foods are often a good source of certain nutrients. Cutting them out of your diet could lead to nutritional issues in the long-term. Reading through material in support of this theory, I liked the approach some had for an 80/20 rule. The idea being that 80 percent of your plate should be alkaline foods, and 20 percent of your plate should be acidic foods. Alkaline theory aside, a plate plump with produce, and moderate amounts of meat or grain is a smart goal for any of us.

And while many of the alkaline diet claims are yet unproved, there is some evidence that there could be certain benefits to a more alkaline, produce-rich diet. One study looked at the evidence and found some interesting information. The JEPH study concluded that a more alkaline diet could be helpful for the following:

1. “Increased fruits and vegetables in an alkaline diet would improve the K/Na [potassium-to-sodium] ratio and may benefit bone health, reduce muscle wasting, as well as mitigate other chronic diseases such as hypertension and strokes."

2. It may improve cardiovascular health, memory and cognition because of an increase in growth hormone.

3. An increase in intracellular magnesium, which is required for the function of enzyme systems, is another added benefit. Available magnesium, which is required to activate vitamin D, would result in numerous added benefits.

4. Chemotherapy is influenced by pH, and one theory is that increased alkalinity may make the treatment more effective.

There are a lot of unanswered questions about the alkaline diet, but there is plenty of evidence that a produce-rich diet can be a benefit without the need to prove that it has a direct effect on blood pH. 

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