Keto Diet And Cancer: Friend Or Foe?

keto-breakfast.jpg is reader – supported.  If you click on a link or buy something via a link on this page, we may earn commission.

Written By: Zan Strumfeld

It’s a question that has circulated since the fad began: can the ketogenic diet help prevent—or cure—cancer? I’m going to tell you now—it’s still unclear. But, a number of studies have started showing unexpected promise for the increasingly popular low-carb diet. Here’s a glimpse at what they’ve found so far.

But First: What Exactly is the Keto Diet?

The ketogenic diet—keto diet, for short—calls for a drastic reduction of carbohydrates and a high intake of fat. This means eliminating any high-carb/high-sugar foods from your diet: no sources of refined sugars, processed grains, whole grains, starchy vegetables and even most fruits. Instead, you’ll take in fat…and not much else. Think unprocessed meats (bacon is a-ok), fish, eggs, vegetables that grow above the ground (read why), and nuts, in moderation.

Once your body begins adjusting to the diet, you’ll fall into what’s called “ketosis,” or a natural metabolic state. Without carbs, your body solely burns the fat, making ketones, a natural acid that moves to the bloodstream. Here’s where your body starts maximizing weight loss and supplies a high amount of energy for the brain.

Note: it’s important to measure your ketone levels (an easy thing to do at home) to make sure you’re hitting optimal levels to reach your weight loss goals.

All in all, you’ll lower your blood sugar and insulin levels dramatically. And, what you’re probably seeking in the first place: quick weight loss. Also, keep in mind there are a few different types of keto diets, based on your desired results.

Yet, while the diet will most likely help you drop the pounds, it’s important to look at some of its noted controversy—especially on how to keep the weight off. It’s never a bad thing to keep tabs on some side effects and risks.

Keto and Cancer: Fighting Combo?

For cancer patients, nutrition is key. Cancer treatments like surgery, chemotherapy, and radiation can be harsh on the body, so keeping a healthy and stable diet is crucial. (Check out these five vegetables to lower your cancer risks.)

But here’s where things get a bit tricky. Currently, most of us are under the impression that sugar can cause cancer, or helps fuel cancer cells. Even though research does show that obesity increases the risk of certain types of cancer, including ovarian and pancreatic, there still isn’t strong evidence that following a sugar-free diet lowers cancer risks or boosts survival rates. In fact, all cells, including cancerous ones, use glucose as their primary source of fuel. Healthy cells need sugar, and there’s no way to provide glucose for them and not the cancer cells. And, some research claims that an ultra-low-carb diet could actually damage long-term health by removing good sources of fiber and vitamins from the diet. Many keto-safe foods, like high intakes of red meat, can actually increase your cancer risk.

Still with me? Well, with all that said, a number of studies have found a link between the keto diet and slowed growth of tumors in mice. One specific study found that, compared to a standard diet, the keto diet increased survival in mice by 56%, bumping up to 78% when combined with oxygen therapy.

In September 2018, researchers at the University of Alabama at Birmingham stated that “women with ovarian or endometrial cancer who followed the ketogenic diet for 12 weeks lost more body fat and had lower insulin levels compared to those who followed the low-fat diet.” The study showed a number of favorable effects in two of the deadliest cancers among women, often linked to obesity and high levels of insulin. The study authors are currently hoping to expand their research to the impacts of the keto diet on cancer treatment.


Helpful or Harmful?

Depending on your type of cancer or treatment, Senior Clinical Dietician at MD Anderson Cancer Center Maria Petzel says, the keto diet can be helpful for some, and harmful for others. As cancer is a case-by-case issue, the body may not be able to break down the high proteins and fats required in the keto diet, leading to digestive issues. Petzel recommends speaking with a dietician and nutritionist before trying a life-changing diet.

Read It Yourself

There are a number of books pro-Keto/Cancer that may be worth looking into with more in depth research. Check out: Keto For Cancer: Ketogenic Metabolic Therapy as a Targeted Nutritional Strategy by Miriam Kalamian, EdM, MS, CNS; Fight Cancer with a Ketogenic Diet by Ellen Davis, MS; Tripping over the Truth: How the Metabolic Theory of Cancer Is Overturning One of Medicine's Most Entrenched Paradigms by Travis Christofferson.

The Takeaway

Whenever you jump into a new, lifestyle-altering diet, your physical and mental health is going to change. There are plenty of benefits to a low-carb diet: appetite reduction, immediate weight loss, increased levels of good cholesterol, and much more. And, the keto diet actually began in the 1920s for the treatment of epilepsy. (It was mostly prescribed for children, with not enough backing research to prove beneficial for adults). So it’s been around a long time with quite a number of positive outcomes.

If cancer comes into effect, the best treatments should include both lifestyle and dietary adjustments for improving overall health, especially when undergoing treatments like chemotherapy and surgery. As for moving forward with the keto diet—that’s your call. Unfortunately, there hasn’t been enough long-term research to truly provide the information most of us desire. If you’re currently going through treatment, consult with your doctor and dietician before deciding to move forward with the keto diet.