Baking soda (sodium bicarbonate) is a natural substance with a variety of uses. It has an alkalizing effect, which means it reduces acidity. You may have heard on the internet that baking soda and other alkaline foods can help prevent, treat, or even cure cancer. But is this true?

Cancer cells thrive in an acidic environment. Proponents of the baking soda theory believe that reducing the acidity of your body (making it more alkaline) will prevent tumors from growing and spreading.

Proponents also claim that eating alkaline foods, like baking soda, will reduce the acidity of your body. Unfortunately, it doesn’t work that way. Your body maintains a fairly stable pH level regardless of what you eat.

Baking soda can’t prevent cancer from developing. There is, however, some research suggesting that it might be an effective complementary treatment for people who have cancer.

This means you could use baking soda in addition to — but not instead of — your current treatment.

Continue reading to get a solid overview of the medical research examining the relationship between acidity levels and cancer.

Remember back in chemistry class when you used litmus paper to check the acidity level of a substance? You were checking the pH level. Today, you might encounter pH levels while gardening or treating your pool.

The pH scale is how you measure acidity. Its goes from 0 to 14, with 0 being the most acidic and 14 being the most alkaline (basic).

Something with a pH level of 7 is neutral. It’s neither acidic nor alkaline.

The human body has a very tightly controlled pH level of about 7.4. This means that your blood is slightly alkaline.

While the overall pH level remains constant, levels vary in certain parts of the body. For example, your stomach has a pH level between 1.35 and 3.5. It’s more acidic than the rest of the body because it uses acids to break down food.

Your urine is also naturally acidic. So testing the pH level of your urine doesn’t give you an accurate reading of your body’s actual pH level.

There’s an established relationship between pH levels and cancer.

Cancer cells typically alter their environments. They prefer to live in a more acidic environment, so they convert glucose, or sugar, into lactic acid. The pH levels of the area around cancer cells can drop as low as 5.5. This makes it easier for tumors to grow and spread to other parts of the body, or metastasize.

Acidosis, which means acidification, is now considered a hallmark of cancer. Many research studies have been conducted to investigate the relationship between pH levels and cancer growth. The findings are complicated.

There’s no scientific evidence to suggest that baking soda can prevent cancer. It’s important to remember that cancer grows quite well in healthy tissue with normal pH levels. Additionally, naturally acidic environments, like the stomach, don’t encourage cancer growth.

Once cancer cells begin to grow, they produce an acidic environment that encourages malignant growth. The goal of many researchers is to decrease the acidity of that environment so that the cancer cells aren’t able to thrive.

A 2009 study published in Cancer Research found that injecting bicarbonate into mice reduced tumor pH levels and slowed the progression of metastatic breast cancer.

The acidic microenvironment of tumors is likely the leading cause of chemotherapeutic failure in cancer treatment. Cancer cells are difficult to target because the area around them is acidic, but inside they’re alkaline. Many cancer drugs have trouble passing through these layers.

Several studies have evaluated the use of antacid drugs in combination with chemotherapy. Proton pump inhibitors (PPIs) are a class of drugs widely prescribed for the treatment of acid reflux and gastroesophageal reflux disease (GERD). Millions of people take them. They have few side effects.

A 2015 study published in the Journal of Experimental and Clinical Cancer Research found that high doses of the PPI esomeprazole significantly enhanced the antitumor effect of chemotherapy in women with metastatic breast cancer.

A 2017 study published in the World Journal of Gastroenterology evaluated the effects of combining the PPI omeprazole with chemoradiotherapy (CRT) treatments in people with rectal cancer. The omeprazole helped relieve common side effects of CRT, improved the effectiveness of the treatments, and reduced the recurrence of rectal cancer.

Although these studies had small sample sizes, they’re encouraging. Similar large-scale clinical trials are already underway.

If you want to reduce the acidity of a tumor, talk to your doctor about a PPI or the “do-it-yourself” method, baking soda. Whichever one you choose, speak to your doctor first.

The study that treated mice with baking soda used the equivalent of 12.5 grams per day, a rough equivalent based on a theoretical 150-pound human. That translates to about 1 tablespoon per day.

Try mixing a tablespoon of baking soda into a tall glass of water. If the taste is too much, use 1/2 tablespoon twice a day. You can also add some lemon or honey to improve the taste.

Baking soda isn’t your only option. There are many foods known to be naturally alkaline-producing. Many people follow a diet that focuses on alkaline-producing foods and avoids acid-producing foods.

According to a 2012 medical review published in Nutrition and Metabolism, a long-term alkaline diet can bring the body’s pH level down toward the lower end of the normal range (7.36 to 7.38). It can’t, however, bring the body’s pH level below the normal range.

Here are some common alkaline and acidic foods:

Alkaline foods to eat

  • vegetables
  • fruit
  • fresh fruit or vegetable juices
  • tea
  • eggs
  • chicken breast
  • tofu and tempeh
  • nuts and seeds
  • cottage cheese
  • organic milk
  • all cooking oils, including olive oil and canola oil
  • grains, such as rice, corn, wheat, barley, oats, and quinoa
  • cheese and butter
  • nut butters, including peanut and almond butter
  • meat products (fish, shellfish, and red meat, fresh and processed such as corned beef and turkey)
  • pasta
  • beans and legumes
  • alcohol (beer, wine, spirits)

Acidic foods to avoid

Baking soda can’t prevent cancer, but when combined with chemotherapy, it could help slow its progression and prevent it from spreading to other parts of the body.

While baking soda might work, there are other options.

Talk to your doctor about PPIs like omeprazole. They’re safe and have few side effects.

Never discontinue doctor-prescribed cancer treatment. Discuss any complementary or supplementary therapies with your doctor.