Does Carbohydrate Restriction Fight Cancer? Use the Warburg Effect to Fight Cancer

Have we known that carbohydrate restriction fights cancer for nearly 100 years? One of the defining characteristics of cancer cells is the inefficient metabolism of glucose to lactate even in the presence of oxygen. This aerobic glycloysis (the breakdown of glucose by enzymes without oxygen) is known as the Warburg effect and has been known since the 1920s. Yet, little has been done to utilize this fact in helping to prevent or treat cancer.

The National Cancer Institute predicts that “in 2018, an estimated 1,735,350 new cases of cancer will be diagnosed in the United States and 609,640 people will die from the disease.”

In spite of all the cancer research, the number of people getting cancer in on the increase.

New Cancers in the United States

Shouldn’t we limit the primary nutrient of cancer cells as a means of fighting cancer?

Sugar is a Key Nutrient for Cancer Cells

Your body typically processes glucose (a sugar from carbohydrates) in two ways. Each way produces ATP molecules (adenosine 5′-triphosphate, the energy source for all cells of the body).

The efficient production of ATP molecules occurs in the presence of oxygen. With oxygen, each glucose molecule is completely oxidized to carbon dioxide and water. This process produces 36 to 38 ATP molecules.

But, when oxygen is not present in sufficient amounts, glucose is converted to pyruvate and further reduced to lactate which enters the blood stream. In this manner, a molecule of glucose can produce only 2 ATP molecules.

In contrast, production of ATP molecules from fatty acids in the presence of oxygen is far more efficient. Fats can produce 146 to 163 ATP molecules. If oxygen is available but glucose is in low supply, healthy cells, but not cancer cells, can produce ATP molecules from fat.

In the 1920s Otto Warburg observed that normal cells in the presence of oxygen inhibited lactate production. But, tumor cells (including cancer cells) maintained lactate production in spite of the presence of sufficient oxygen. In fact, cancer cells consumed ten times the glucose and produced two orders of magnitude (often 200 times) more lactate than normal cells.

Love of Sugar Helps Identify Cancer Cells

It is this “addiction” to excess glucose by cancer cells that enables the detection of many cancers. FDG-PET (fluorodeoxyglucose positron emission tomography) is often used to detect, diagnosis and monitor many cancers. Before the PET scan you receive intravenous injection of a tracer dose of mildly radioactive sugar (glucose). This radioactive glucose will be attracted preferentially to cancer cells where it can be easily detected in a PET scan.

This detection technique works well for many types of cancers including lung cancer, breast cancer, colorectal cancer, melanoma, Hodgkin lymphoma, endometrial cancer, and soft tissue and bone sarcoma. Some cancers do not seem to gulp down the radioactive sugar and are difficult to detect with a FDG-PET scan. These include liver cancer, prostate cancer and pancreatic cancer.

Does Sugar Help Cancer Develop?

The presence of excessive amounts of blood sugar seem to increase the risks of many types of cancers. Some think that the aerobic glycolysis within cancer cells may provide a growth advantage that helps cancer cells replicate. This is especially important among diabetics with insulin resistance who have trouble removing sugar from the blood stream. Diabetics have twice the risk for cancers of the liver and pancreas as well as for endometrial cancer. Diabetes also increases the risk for colorectal, breast and bladder cancers by 20 to 50%.

Metformin, a common diabetes drug, helps improve insulin sensitivity so sugar can be removed from the blood stream and it helps reduce gluconeogenesis (the generation of new glucose in the body). Metformin seems to help reduce cancer growth that would otherwise be stimulated by a high-energy diet. Compared with other diabetes drugs, metformin shows a significant 31% decrease in cancer risk among diabetes patients.

Cancer Prevention and Treatment with Diet

It seems an obvious question, but, can reducing the availability of sugar in the diet play a role in preventing or treating cancer?

Reducing the availability of sugar means consuming few, if any, carbohydrates. As you probably know, carbohydrates comprise a category of foods that are digested or broken down by enzymes into simple sugars. These foods include grain foods (like bread, rice, pasta), fruits and fruit juices, dairy products (especially with added sugars like most yogurts), starchy vegetables (like potatoes and corn), and all sugary beverages, treats and desserts.

The ketogenic diet is a popular way of greatly reducing carbohydrates. It allows moderate protein, with a shift from carbohydrates to healthy fats. This type of diet is used primarily to force the body to burn fat rather than glucose (sugar). There are many books available discussing the ketogenic diet and providing recipes for delicious meals.

A number of studies have been done to test the effectiveness of the ketogenic diet on cancer. Many initial studies were done on mice, but more recent studies have involved human cancer patients. But, because diet is not an “approved” cancer therapy, most human studies are done as a last resort after the traditional therapies favored by the cancer industry have failed.

Here are just a few such studies:

Mouse Study 1

In one mouse study a mouse brain tumor (CT-2A) was induced in mice by a chemical carcinogen. This mouse tumor and the human U87 tumor were then implanted in the right flanks of subject mice. Before implanting the tumors all mice were feed a standard diet of PROLAB chow.

These mice were separated into six groups (2 tumor types x 3 diets) and feed different diets consisting of

  • Standard PROLAB chow (ad libitum, as much as they wanted)
  • KetoCal®,a nutritionally complete ketogenic formula designed for children with epilepsy (ad libitum)
  • KetoCal® (calorie restricted to reduce body weight by approximately 20%)

The tumors grew rapidly in mice feed ad libitum, but exhibited slower growth rates in mice feed a calorie restricted diet. The CT-2A and U87 tumor growth was reduced by approximately 65% and 35% in the KetoCal® calorie restricted mice. These mice also showed slower growth of new blood vessels to tumor cells.

Mouse Study 2

In this mouse study 24 mice were fed a standard mouse diet before they were injected with human gastric adenocarcinoma cells. The mice were then divided into two groups and feed either:

  • a ketogenic diet enriched with omega-3 fatty acids and medium chain triglycerides ad libitum
  • a standard mouse diet ad libitum

The study looked to see how quickly the tumors reached a target size.

Tumors in the ketogenic diet group reached the target tumor volume in an average of 34.2 days while it took only 23.3 days for the mice in the standard diet group. It took 28 days for the last mice on the standard diet to reach the tumor target volume. But, it took 45 days for the last mice on the ketogenic diet to reach the target tumor volume.

Human Study 1

This study involves two pediatric oncology patients with advanced stated cancers that could not be removed. One patient was a 3 year old girl with stage IV anaplastic astrocytoma (malignant brain tumor) who no longer responded to radiation and chemotherapy. The second patient was an 8 1/2 year old girl with low grade cerebellar astrocytoma (brain tumor in the cerebellum) who underwent radiation, chemotherapy and an operations to remove 95% of her cerebellum.

The first patient started a ketogenic diet resulting in a 21.77% decrease in FDG uptake for PET scans and no changes in the tumor size while on the keytgenic diet. The patient remained on the ketogenic diet for 12 months after the study and showed no measurable progression of the tumor. She increased her ability to sit and stand without assistance and developed better control over bodily functions.

The second patient started the ketogenic diet and subsequent PET scans showed a 21.84% decrease in FDG uptake indicating decreased glucose metabolism within the tumor.

With both patients, the ketogenic diet significantly affected tumor metabolism.

Human Study 2

This 3-month long study involved 16 patients with advanced metastatic tumors who had no exhausted traditional therapeutic options. These patients were given instructions about following a ketogenic diet (with less than 70 g of carbohydrates per day) using normal groceries. They were provided with a supply of food supplements allowing them to create a protein/fat shake to make getting nutrients easier.

General health parameters were measured and a quality of life survey was administer every two weeks during the study. Two patients died of their disease, several discontinued the diet because of their disease and several dropped out because they found the diet difficult to follow.

Five patients completed the 3-month study. They reported improvements in their emotional functioning and less insomnia. But, their physical functioning became only slightly worse. The 5 patients who adhered to the diet for the entire 3 months had stable disease and lost weight.

The Ketogenic Diet and Cancer

Dr Michael VanDerschelden explains how a ketogenic diet can prevent and even cure cancer by depriving cancer cells of glucose, which is their only energy source.

Conclusions You Can Use

Most of us know that consuming high levels of carbohydrates causes weight gain (and all the other negative consequences of excess weight). Carbohydrates are digested into simple sugars that enter the blood stream. And, now for nearly a century research has shown that glucose in the blood is the chief nutrient of cancer cells.

It only makes sense that cutting down on blood glucose would help reduce the growth and spread of cancer cells.

For your own health, you should limit consumption of carbohydrates, especially simply carbohydrates like sugar that spike glucose levels in the blood.

References

Leave a Reply

Your email address will not be published. Required fields are marked *