Collage of mixed fruits and vegetables, MRI, by Wellcome Images.

Collage of mixed fruits and vegetables, MRI, by Wellcome Images.

Cancer. It’s one of the few diseases with a personality. The F*ck Cancer meme is much stronger than the F*ck Heart Disease meme, even though both kill a similar number of human beings. While both diseases can develop with no obvious warning signs, cancer is perceived as a sneakier, meaner disease.

Maybe that’s because cancer is mysterious. There are more than 200 different types, and risk factors and causes are multitudinous: genetics, chemical exposure, radiation exposure (including sunlight), age, certain viruses, smoking, alcohol abuse, lack of exercise … the list goes on.

But cancer isn’t a death sentence. As several of the older members of my family have experienced in the past few years, cancer can be successfully treated. Though my family members used both conventional treatments and lifestyle changes, sometimes cancer goes away with lifestyle changes alone.

About half of people in developed countries will be diagnosed with some kind of cancer in the course of their lives. 100% of middle-aged or older people will have small pockets of abnormal cell growth — microcancers — most of which will be either too slow-growing to ever cause a problem, or will be eliminated by the immune system. And if you get cancer and beat it, the only way you know for sure you are “cured” is when you die of something else.

Nobody is totally safe from cancer, but there are things we can do to improve our chances of not developing the disease in the first place. While genetic risk factors play a significant role, so do environmental (lifestyle) factors. The clinical research is there to prove it. We can prevent cancer (or at least improve our odds) in at least seven ways:

  1. Reduce exposure to mutagens.
  2. Maintain adequate vitamin D levels.
  3. Use fasting and intermittent fasting.
  4. Keep angiogenesis in check.
  5. Consume foods that kill cancer cells or cause them to self-destruct.
  6. Stay (or get) lean, and improve insulin sensitivity.
  7. Stimulate your immune system with physical exercise.

I realize these are abstract. I’ll get into behavioral recommendations within each category. Some behaviors (like not smoking, or quitting smoking) are an order of magnitude more effective against cancer than other behaviors (reducing or eliminating red meat, or staying out of the sun).

So, getting into the details …

1. Reduce exposure to mutagens.

Mutagens are factors that damage DNA and increase the risk of abnormal cell growth. This article provides a good overview of categories of mutagens and tumor promoters.

What can you do to reduce your exposure to mutagens? In probable order of importance:

2. Maintain adequate vitamin D levels.

Higher vitamin D are associated with lower rates of several types of cancer, especially colorectal cancer, but also prostate and breast cancer. But why? According to this paper:

Vitamin D and its metabolites reduce the incidence of many types of cancer by inhibiting tumor angiogenesis,182185 stimulating mutual adherence of cells,186 and enhancing intercellular communication through gap junctions,187 thereby strengthening the inhibition of proliferation that results from tight physical contact with adjacent cells within a tissue (contact inhibition).

Clinical studies show benefits both from supplemental vitamin D, and vitamin D from sunlight. If subsequent research demonstrates that the latter is more effective, it may be because of sunlight’s role in converting nitrates on the skin to nitric oxide. Nitric oxide can act both as a mutagen (promoting skin cancer), but can also be cytotoxic for tumor cells.

My own approach is to supplement moderately with vitamin D (10-20K IU/week) and get some non-burning, direct (no sunscreen) sun exposure at least a few times a week. I do use sunscreen on my face, which already has some sun damage (as do most fair-skinned people who have grown up in California).

What is the ideal blood level of vitamin D? There is no global medical standard, but a target range of 40-80ng/ml provides protection against many cancers and has a low risk of side  effects.

3. Use fasting and intermittent fasting.

While there isn’t enough clinical research to support the idea that fasting can help prevent cancer, there are some intriguing studies.

According to this study, fasting before chemotherapy greatly reduced chemo side effects.  In addition, fasting sensitized some types of cancer cells to chemotherapy.

Fasting may “reboot” the immune system by triggering stem cell regeneration.

It’s clear that fasting and intermittent fasting are a form of metabolic stress, and that this stress generally allows cells to “clean out the gunk” and recycle damaged organelles. But how, exactly, does this work? Even for cancer researchers, it’s a difficult question. Trying to understand the process myself from papers such as this one, I run into sentences like this:

Exactly how metabolic stress triggers apoptosis is not completely understood, but it is associated with the induction of the pro-apoptotic BH3-only protein PUMA, requires the BH3-only protein BIM, depends on either BAX or BAK, and is inhibited by BCL2 (REFS 30,33,34). Once the apoptotic signal reaches BAX and BAK, mitochondrial membrane permeabilization, caspase activation and cell death occur in less than an hour and the process is extremely efficient and irreversible (FIG. 1a). Neighbouring cells or professional phagocytes engulf apoptotic cells, preventing the activation of an innate inflammatory response. These attributes are the reasons why apoptosis defects are selected for in tumours and why restoring the apoptotic response is desirable for cancer therapy. Tumour cells with defects in apoptosis through either deficiency in BAX and BAK or gain of BCL2 or BCL-XL (also known as BCL2L1) function are highly resistant to metabolic stress and the properties of these ‘undead cells’ are revealing insights into the mechanisms regulating metabolic stress response.

The details are beyond my current comprehension level, but I suspect that fasting and intermittent fasting play some role in preventing cancer. I’ll continue with my once-weekly IF practice for the foreseeable future.

4. Keep angiogenesis in check

Eating foods that reduce the rate of new blood vessel growth (including tea, berries, soy, and many other foods) may slow cancer growth and reduce invasiveness. William Li discusses the topic in detail in his TED talk.

5. Consume foods that kill cancer cells or cause them to self-destruct.

Many foods (including herbs and spices) specifically target specific cancers. Compounds in citrus peel inhibit the growth of lung cancer. Ginger is effective against prostate cancer. Garlic helps protect against breast cancer. Compounds in cruciferous vegetables, including indole-3-carbinol, inhibit growth of a wide range of cancers. Curcumin, found in turmeric, provides some protection from at least nine types of cancer. Curcumin’s anti-cancer effects may be due to the downregulation of a number of inflammatory pathways. Compounds in spicy peppers greatly inhibit the growth of prostate cancer.

High coffee intake is associated with reduced liver cancer risk, possibly due to compounds in coffee reducing inflammation and cell damage in the liver. Drinking coffee may also reduce the risk of pancreatic cancer in men.

What reversed the cancer of Stamatis Moraitis? Maybe it was the wild Ikarian herbs (including wild marjoram, sage, and rosemary). Maybe it was the olive oil (oleocanthal, in olive oil, destroys the lysosomes in cancer cells but not in healthy cells).

Food can be medicine when it comes to preventing cancer, and in some cases as an adjunct treatment (in addition to whatever medically proven intervention is taken, be it chemotherapy, radiation therapy, or surgery). It’s hard to go wrong eating lots of plants, especially bitter ones, and especially herbs and spices.

6. Improve insulin sensitivity.

Testimonials like this one (a woman’s brain tumor shrinking after switching to a paleolithic diet and losing a great deal of weight) intrigue me. What is the relationship between reducing dietary carbohydrates, losing weight, and cancer?

Evidence suggests that too much circulating insulin and IGF-1 (insulin-like growth factor) are associated with increased cancer risk and tumor initiation and progression. Obesity is associated with cancer mortality, probably due to high circulating insulin.

Increased cancer risk in night-shift workers may be due to metabolic shifts caused by circadian disruption.

It follows that lifestyle interventions that increase insulin sensitivity (increased exercise, fat loss, reduced intake of simple carbohydrates, better sleep) can potentially reduce cancer risk. Dan Pardi has a great post that discusses this topic, including the use of the diabetes drug metformin to prevent cancer, and how starving cancer cells of glucose (via a ketogenic or very low carbohydrate diet) may be an effective anti-cancer therapy.

This study found that an extended overnight fast reduced breast cancer risk in women via improved glycemic control.

7. Stimulate your immune system with physical exercise.

Exercise has long been associated with reduced cancer risk and improved cancer prognosis. Some of this association is due to countering obesity and improving insulin sensitivity. But there appears to be an independent immune-stimulating effect of exerciseThis article explains the study quite well. Though the study looked at mice, not humans, it revealed an important mechanism (exercise stimulates the release of adrenaline, which increases interleukin-6, which helps the immune system fight cancer).

Conclusion, and considering alternative cancer therapies

Unless you live in a country with very low life expectancy, you will be effected by cancer one way or another, at some point in your life. It’s very likely that you and/or a family member will be diagnosed with some form of cancer or precancerous condition.

If you have access to modern medical care, use it. Thousands of people die prematurely, each year, from delaying or avoiding allopathic treatment (surgery, radiation therapy, chemotherapy) and relying solely on “alternative” therapies, including many I’ve touched on in this post.

If someone tells you “all you have to do to cure cancer is follow a raw vegan diet” (or alkaline diet, or ketogenic diet, or paleolithic diet), don’t believe them. Don’t put your life in their hands. The evidence just isn’t there.

At the same time, even the most competent oncologist or cancer surgeon may not be up to date with how compounds in foods promote or inhibit cancer. Nutritional and other lifestyle interventions can greatly reduce cancer risk, and improve post-cancer prognosis. So do your own research and make the appropriate health/lifestyle changes based on what you learn.

I wrote this post primarily as a resource for my family and friends, but I hope many people can benefit from it. Good health to you and your family. May you live long and prosper.