The association between nutrition and cancer as well as other chronic diseases is not new. Though there are other risk factors, nutrition ranks among the most important, because it can be modified at the individual level and be targeted by public health policies. You probably already know that junk food, though delicious, is bad for you. It can have negative health effects such as increasing your risk of heart disease, metabolic disease, and even cancer. Diet is among the few modifiable risk factors for cancer prevention.
Research shows that a very high percentage of all human cancers are driven by the effects of glucose and insulin, which stimulate the proliferation, migration, and invasiveness of all types of cancers. It is because sugar is cancer’s favorite food that PET scans can detect active cancer sites. Before patients undergo a PET scan, they first must fast and then receive an injection of radioactive sugar. The sugar circulates in the bloodstream and is gobbled up by hungry cancer cells that light up the scan like a glow stick. The higher the rate of glucose consumption (that is the more densely lit the cancer cells appear on the scan), the more aggressive the tumor.
Intermittent and chronically elevated levels of blood sugar and insulin are the foundation for all progressive and recurrent cancers. This state stimulates cancer growth, inhibits cell death, promotes metastasis, helps cancer cells resist radiation and chemotherapy, and increases complications from surgery and chemotherapy. What’s more, ingesting any type of sugar, – glucose, fructose, sucrose, honey, even freshly squeezed juice – reduces the activity of certain immune cells by half for up to 5 hours following consumption.
Elevated glucose and insulin can cause metabolic imbalances throughout the body which can provide a hospitable environment for cancer. Increased metabolism of glucose promotes several hallmarks of cancer including the excessive proliferation of cancer cells, antiapoptotic signaling (helps cancer cells remain immortal), and angiogenesis (development of new blood vessels). In addition to feeding the cancer beast and helping it grow, high levels of glucose and insulin stimulate cancer-promoting pathways. Insulin stimulates the release of pro-inflammatory chemicals called cytokines from human fat cells. A diet that repeatedly elevates blood glucose levels promotes a pro-inflammatory environment that is considered the match that lights the fire of cancer. It is crucial to limit your intake of glucose if you want to stop cancer and even other non-communicable diseases. But cancer in particular has a very strong sugar addiction, and it has figured out a very clever way to use it.
Abnormal cancer metabolism creates a glycolytic dependency which can be exploited by lowering glucose availability to the tumor. The ketogenic diet (KD) is a low-carbohydrate, high-fat diet which decreases blood glucose and elevates blood ketones and has been shown to slow cancer progression in animals and humans. The ketogenic diet forces a physiological shift in substrate utilization from glucose to fatty acids and ketone bodies for energy. Normal healthy cells readily adapt to using ketone bodies for fuel, but cancer cells lack this metabolic flexibility, and thus become selectively vulnerable to reduced glucose availability. One of the potential benefits of ketogenic diets for cancer therapy is the potential for enhancing the effect of drugs, radiation, or other modalities. Studies showed that the combination of chemotherapeutic agents with a ketogenic diet at the same time, may provide more reliable outcomes and allow lower doses of anti-cancer chemo and radio-therapeutic modalities to reduce toxicity and side effects. The metabolic transition from glucose to ketone bodies reduces tumor angiogenesis and inflammation while enhancing tumor cell apoptosis.
