Do Fruits and Vegatables Prevent Cancer?

The answer in one word is "unproven." A large study involving 500,000 Europeans over a multi-year basis failed to show a definitive correlation between cancer development and fruit and vegetable consumption.

So if that's the case, why is it important to eat such whole foods?

Before I give you an answer, I want to point out the trap that you may have fallen into by even considering this question. If you've been reading this blog for some time, then at this point you should realize that when it comes to your health, X usually does not cause or prevent Y.

Yes, there are some notable exceptions like cigarette smoking causing lung cancer, trans-fats causing heart disease, etc. but it's almost never so simple.  True, we also know that sufficient levels of Vitamin A prevent night blindness, of niacin prevent pellagra, of Vitamin C prevent scurvy, etc. In other words, there are known cause and effects for certain diseases, but it's usually not one thing alone that causes the major killers such as heart disease, cancer, etc.

Why? The human body is a very complicated machine that is usually able to handle many imperfections (like autoimmune diseases, etc.) and environmental assaults (unhealthy foods, etc.) before it breaks down and stops working completely. It has many built-in mechanisms such as the immune system, the complement system, etc. that fight to fix problems before they wreak havoc.

Even in the case of really harmful things like smoking, not everyone develops lung cancer, one of the known consequences. Sometimes smokers die from the heart damage that smoking does and sometimes they die from something completely unrelated. (Many smokers who don't develop cancer from smoking do develop other lung diseases like emphysema and Chronic Obstructive Pulmonary Disease (COPD), the fourth highest killer of Americans.)

The point here is that it would be a mistake to think that anything, including fruits and vegetables, considered in isolation would prevent major diseases such as heart disease, the leading killer of Americans, and cancer, the second leading cause of death.

It is the sum of the parts that ultimately make a difference. If one eats lots of fruits and vegetables but simultaneously eats lots of processed sugar and other known carcinogens, the fruits and vegetables are unlikely to yield a high preventive effect.

So now let's come back to my question of why it is important to eat fruits and vegetables in regards to cancer.

The answer is that while no study has distinctly proven a cause and effect relationship between the amounts of fruits and vegetables one consumes (once above the deficiency threshold and below the toxicity level) and the development of cancer, there are certain factors that have proven to be strong risk factors for cancer development. One is weight. Overweight and obese people appear to have a markedly increased risk for development of a variety of types of cancer affecting both men and women. It is also a strong risk factor for cancer recurrence. For most people, their weight is a direct result of the types of foods they eat. People who typically eat more fruits and vegetables usually eat less processed foods like breads, crackers, pasta, etc. and weigh less. (See my previous posts 'Why You Get Fat?'  and the two part 'Why You Stay Fat?' for a more exhaustive discussion.)

As I previously wrote about a close relative that was recently diagnosed with cancer, I have taken a keen and deeper interest in the subjects of cancer prevention and survivability so that I may offer this relative the best guidance.

After review of hundreds of cancer prevention studies, I have reached some very tentative conclusions.

Fruits and vegetables alone (and clearly supplements including vitamins, minerals, antioxidants, etc. naturally found or synthetically produced to mirror such chemicals) do not alone prevent cancer.

However, as part of an otherwise healthy lifestyle that includes avoidance of known carcinogens such as smoking, drinking lots of alcohol, being overweight, exposure to environmental hazards such as asbestos and numerous other substances and chemicals such as acrylamide that develops on the surface of french fries during the frying process, nitrites used to preserve cured meats, certain food dyes, pesticides, and other chemical additives, etc., eating fruits and vegetables is likely to cut down one's risk of both developing cancer and dying from it.  As I previously wrote, the risk of men developing cancer is 1 out of 2 and of dying from it is 1 out of 4. For women, the numbers are slightly better with the risk of developing it being 1 out of 3 and of dying of it being 1 out of 5.

Cancer remains mostly a disease of random mutations instead of genetics.  What causes these mutations, why some get it versus others, and why some survive the exact same cancers while others die from them remains an issue of scientific debate. While science continues to try to figure it out, do yourself a favor and shift the odds in your favor. Substitute fruits and vegetables in place of processed foods, in addition to making many other known healthy lifestyle choices such as regular exercise, getting proper sleep, etc.  By doing so, you will give your body every opportunity to function at the optimal health level and to continue functioning for many more good years.

Waiting for cancer?

Let me tell you a very personal story. About three weeks ago, I got a phone call in the evening from a close relative. During the call, I was informed that this person had been diagnosed with cancer. A week later the person called again and notified me that a second cancer had also been diagnosed.  I was devastated and I am still reeling from the news. I love this person very much and can only imagine how dreadful it is for someone to be diagnosed with cancer and what fear it must invoke. Of course, when a close relative develops a serious illness, other family members are surely also concerned about the risk to their own health of developing a similar disease.  Such news brings pain to all quarters.

According to the American Cancer Society, the risk of a man developing cancer is 1 in 2 and of dying of cancer is 1 in 4. The risk of a woman developing cancer is 1 in 3 and of dying of cancer is 1 in 5. You have to be a Luddite not to be concerned about such odds and the personal risk to you of developing this horrific illness.

Although there is clearly a genetic basis for some people to develop cancer, most cancers are random mutations.  In general, it is now believed by credible scientists that virtually all people have cancers cells of one type or another in their bodies at all times due to such random mutations. However, their properly functioning immune system is often capable of dispatching with most of these fledgling cancer cells before they develop into life-threatening tumors.

At this point you may be thinking that if it's only a question of odds, then why not just hope that you will be lucky because what else can you do?  Well, I am here to tell you that there may be a lot to do.

It's well known that professional gamblers using a variety of techniques are able to improve their odds in casinos. For example, counting cards while playing the card game black jack shifts the odds in one's favor over the house. Such subtle shifts can make the difference between vast losses and gains.

In life, can there be any greater loss than the loss of health?

As with gambling, certain human behaviors shift the odds in favor of avoiding or even curing cancer.

Dr. Dean Ornish, in a landmark experiment, demonstrated that a change in diet could stop the expression of prostate cancer. In a limited study, he showed that with certain men, he could arrest the progression of the disease.

It is well established that breast cancer survivors who are overweight have a much higher rate of recurrence of their cancer than comparative normal weight ladies.

There are countless credible studies that support the role of diet and lifestyle in cancer development and death and at this point, almost all doctors agree that lifestyle, including diet, plays a major role in one's health and risk of dying from cancer.

Let's get back to my painful story. After researching the specific types of cancers that my relative had developed, I offered directed recommendations regarding changes in diet and lifestyle that offered hope for improved health and survivability.  After sharing a number of suggested changes, my close relative suddenly uttered that he/she was not prepared to go crazy about his/her diet.

What prompted this response?  My suggestion to eliminate all processed sugar products from the diet.

There has developed a growing body of evidence that sugar stimulates the growth of cancer. It does so by causing the release of insulin which binds to insulin receptors on the surface of solid tumors and stimulates them to grow faster.

When I shared this with a friend yesterday, she asked me why she hadn't heard about the role of sugar in cancer before?  She said her father had died from cancer and one of the country's leading oncologists had never mentioned the need for her father to avoid the sweet stuff.  Unsure of how long it had been since her father passed, I queried and she said that it was about ten years ago.  My response to her question was that scientists did not have as clear an understanding ten years ago as they do today about the dangers of sugar and other dietary intakes on their role in cancer development, progression, and survivability.

As fate would have it, a patient gave me an article two days ago that recently appeared in Mother Jones magazine chronicling the efforts of the sugar industry to suppress the alarming facts regarding the dangers of sugar not only for cancer development, but for heart disease and diabetes as well. Like Big Tobacco before it, the sugar industry has been very successful in confusing the general population into being unalarmed and apathetic about the dangers that sugar poses.

It's gotten so bad that most people actually believe that eating sugar 'in moderation' (however they define moderation) poses no threat to their health. Yet, our country suffers from an epidemic of obesity, heart disease, diabetes and dementia, with a rising tide of metabolic syndrome in which people have elevated blood pressure, sugar and cholesterol.

It may be unfair to single out sugar and its precursors (high glycemic index carbohydrates) as the worst culprits, but the label may actually be accurate. Clearly there are numerous other protagonists responsible for our health problems, including trans-fats, saturated fats, food additives, etc., but sugar laden products such as those containing High Fructose Corn Syrup, deserve special attention.

There are many ways to die, but I can't imagine a much worse way that wasting away from cancer. I still vividly remember as a medical student when I was asked to see a patient in the hospital.  As I entered the room, I saw a very jaundiced looking man with the outlined remains of what I could only imagine were once extremely good looks, who had wasted away and was now close to death from cancer. After addressing his immediate concern for which I had been summoned, I asked if there was anything else I could get him. I still get chills thinking about his response. He answered softly, but assuredly, that I could give him back his health. Then he smiled at me, apparently resigned to his fate.  He died a few days later.

As scientists now know about the major role that food plays in the cancer story, it would be a shame not to take heed of preventive measures that could very well save your life and allow you to enjoy many more years of disease-free living.  I wish I knew in medical school what I know now and I wish I had been able to do more for this stranger. He is long gone, but there are many more than can be helped now.

Let me start by suggesting some basic rules of staying healthy. The top rule is to eat mostly foods that have no labels, such as fruits and vegetables.  Enjoy large amounts of beans, lentils, chickpeas, nuts, and seeds. Consume whole grains on a regular basis particularly the ancient grains such as spelt, quinoa, and millet. Make Wild Salmon a staple of your dinner table, consuming it even every other day if possible.

Of course, you can ignore this advice and gamble with your life and the increased risk of developing cancer.  Or maybe, you now understand the risks and aren't willing to play the odds.

In addition, make sure that you stay physically active by walking at least 7,500 steps (3.75 miles) per day with at least 15 minutes of more intense exertion each day. Get at least 7 hours of sleep a night with at least 3-4 hours of uninterrupted sleep. Manage your stress by learning techniques to deal with life's inevitable stressors such as relatives informing you that they are ill.

The great American poet Robert Frost once wrote that "two roads diverged in the woods" and he "took the one less traveled by, And that has made all the difference."

Are you going to stay on the road traveled by most people of eating whatever they want blinded to the dangers of developing cancer and other horrible diseases that prematurely shorten their lives or simply make life far more difficult OR will you take the road less traveled by, by eating healthier and see if that makes all the difference?

Are you waiting for cancer? Please don't. It's not worth the wait.