It’s becoming more accepted that diet plays a big role before, during and following a cancer diagnosis. The messages about how to approach diet when it comes to cancer however, are unfortunately much less clear. Where once the most widely accepted recommendation to ‘eat whatever you can’ lead the way (and sadly often still does), clear evidence has shown that living off white bread, jello, milk, and ham sandwiches for the sake of maintaining weight after a cancer diagnosis is no longer a safe or effective approach. In replacement, a more scientifically sound regime has emerged; ‘eat to maximize nutrition, not calories’. Within integrative cancer care, this is something we’ve known for years. And to clarify this position even one step further, it’s not about eating more, it’s actually about being more savvy about what you eat, and when. Eating less isn’t something most people enjoy doing, so luckily when it comes to ‘intermittent’ (or ‘short term’) fasting and cancer, you can still eat to enjoy life, and do so while maximizing nutrition during specific periods of the day.

Old School Approach 

The old school approach to cancer is based on the idea that once you’ve been diagnosed with cancer, you need to eat whatever you can to avoid losing weight. This previous perspective is fuelled on the thought that as cancer grows, patients lose weight and eventually become sick. This old idea also suggests that as long as weight is maintained, there will be enough stored calories to prevent a person from losing weight, ‘wasting’ away and thus succumbing to their disease. Although the initial logic to this approach makes sense, an inherent error is overlooked; eating unhealthy food simply for the sake of calories actually feeds and stimulates cancer, which doesn’t help. What approaching cancer should actually be about is optimizing nutrition first, and calories second. This is where fasting and cancer enter perfectly into play. 

Fasting and Cancer: Some Basic Principles

Cancer is a disease of metabolic derangement. Studies show that cultures that incorporate periods of fasting have significantly lower rates of cancer. Western societies tend to have an abundance of food, especially those high in carbohydrates and sugar. This overconsumption leads to chronic inflammation, metabolic malfunctioning and genetic alterations. Cancer arises when this pattern leads to mutations that essentially stick the gas pedal to the floor and drive cells to constantly divide and grow. Caloric restriction, manipulating the types of food we consume, and controlling how much we eat, can greatly impact cancer’s ability to get what it needs to grow and can even signal cancer cells to die. 

Cancer cells, contrary to normal cells, depend on steady glucose availability in the blood for energy and growth demands. In other words, cancer cells thrive on glucose but starve on alternative fuels such as fats and ketones, prominent in both low-carbohydrate and fasting state diets. So, by sporadically fasting, or restricting when foods are eaten, the likelihood of cancer cells being able to survive becomes much less. 

During periods of intermittent (or short term) fasting, cancer cells become stressed. When you fast, healthy cells power down their drive to reproduce and switch to a protect and repair mode, which is healthy. Meanwhile, cancer cells are constantly trying to rapidly divide and rely on an ongoing supply of sugar as fuel. Without their preferred fuel source, the ability of cancer cells to divide becomes much less. In addition, during the rigours of active cancer treatment, short term or intermittent fasting converts cancer cells into open targets to the cytotoxic effects of chemotherapy. During a state of fasting, healthy cells hunker down and are better able to stay out of the line of fire of chemotherapy. Studies have shown that cancer cells, however, become much more susceptible to chemotherapy while allowing patients to experience fewer side effects and better tolerate treatment. 

What does the science say?

Science shows that fasting has an improved ability to protect healthy tissues while increasing cancers cells susceptibility to being killed. Patient’s undergoing conventional cancer therapy tend to experience less nausea, improved appetite, reduced mouth sores and gut issues, and increased overall quality of life. Other improvements gained from intermittent or short term fasting include better blood counts, a heightened immune system, and an overall improvement in tumour response. 

So how do I begin?

There are multiple approaches to intermittent or short term fasting. Here at Cornerstone Naturopathic Inc., we analyze what works best for you, including what to eat, when to eat, and when not to eat. When receiving conventional medical care, we safely work nutrition around specific timing and schedules to ensure maximum benefit.  During non treatment days, approaching fasting and cancer can be as easy as not eating from mid evening until late morning the following day. Many strategies do exist, however it’s all a matter creating the most effective approach for you.