Scientists Show How Certain Vegetables Combat Cancer

vegetables, broccoli, cruciferous, cancer, sulforaphane, SFN, isothiocyanatesWhile it has been known for some time that eating cruciferous vegetables, such as broccoli, cauliflower, and cabbage, can help prevent breast cancer, the mechanism by which the active substances in these vegetables inhibit cell proliferation was unknown — until now.

Scientists in the UC Santa Barbara laboratories of Leslie Wilson, professor of biochemistry and pharmacology, and Mary Ann Jordan, adjunct professor in the Department of Molecular, Cellular, and Developmental Biology, have shown how the healing power of these vegetables works at the cellular level. Their research is published in this month's journal Carcinogenesis.

"Breast cancer, the second leading cause of cancer deaths in women, can be protected against by eating cruciferous vegetables such as cabbage and near relatives of cabbage such as broccoli and cauliflower," said first author Olga Azarenko, who is a graduate student at UCSB. "These vegetables contain compounds called isothiocyanates which we believe to be responsible for the cancer-preventive and anti-carcinogenic activities in these vegetables. Broccoli and broccoli sprouts have the highest amount of the isothiocyanates.

"Our paper focuses on the anti-cancer activity of one of these compounds, called sulforaphane, or SFN," Azarenko added. "It has already been shown to reduce the incidence and rate of chemically induced mammary tumors in animals. It inhibits the growth of cultured human breast cancer cells, leading to cell death."

Dr. Mercola's Comments:

It’s always great to find phtyonutrient-based research being published and getting some well-deserved attention. In general, it is wise to include as many different varieties of vegetables in your diet as you can tolerate, based on your nutritional type.  

As a general rule, the greater the variety and the larger the volume, the better. When it comes to healing carbohydrates, most of the beneficial healing elements of food are in the vegetables, whereas the grains are a major contributing factor to most of our modern culture’s diseases.  

The healing, restorative power of vegetables have been researched and known for some time, but remains largely obscured; overshadowed by the massive marketing of pharmaceutical drugs that seek to provide symptomatic relief, however more expensively, oftentimes less effectively, and with a plethora of damaging health consequences as, unlike vegetables, they nearly always fail to address the cause of the problem.  

For example, one 2001 study discovered that women who reported consuming at least 2.5 servings of fruit and vegetables daily as adolescents were 46 percent less likely to develop ovarian cancer.  I can’t think of any drug that can beat those prevention odds.

The Cancer-Busting Power of Crunchy Veggies 

Several studies have confirmed that certain compounds, called isothiocyanates, in cruciferous vegetables have distinct anti-cancer activity.

Broccoli and even more so, broccoli sprouts, contain the highest amounts of isothiocyanates. Other vegetables containing isothiocyanate include: 

  • brussel sprouts
  • cauliflower
  • cabbage
  • arugula
  • watercress
  • horseradish

The isothiocyanate in these vegetables sparks hundreds of genetic changes, activating some genes that fight cancer and switch off others that fuel tumors.

Said lead author Olga Azarenko: 

“Breast cancer, the second leading cause of cancer deaths in women, can be protected against by eating cruciferous vegetables such as cabbage and near relatives of cabbage such as broccoli and cauliflower.”

As stated in this latest study, one particular isothiocyanate compound called sulforaphane (SFN) has been shown to reduce the incidence and rate of chemically induced mammary tumors in animals. It also inhibits the growth of cultured human breast cancer cells, leading to cell death.

Other studies have confirmed the protective benefits of these vegetables for other types of cancer as well, such as:

  • Bladder cancer – Researchers found that the higher the intake of cruciferous vegetables, the lower the risk of bladder cancer in men
  • Lung cancer – Researchers found that men with detectable amounts of isothiocyanates in their bodies had a 36 percent lower chance of developing lung cancer over 10 years
  • Prostate cancer – This study, published in PLoS ONE in 2008, discovered that just a few additional portions of broccoli each week could protect men from prostate cancer

I have long touted the cancer busting power of broccoli and actually posted my first article on it 11 years ago.

Back then, animal studies had shown that glucoraphanin -- a precursor to sulforaphane – boosts cell enzymes that protect against molecular damage from cancer-causing chemicals. Sulforaphane had also been shown to mobilize natural cancer protection resources, reducing the risk of malignancy.

Now these most recent studies have been able to validate the actions of sulforaphane in humans as well.

The Special Power of Broccoli

Broccoli (as compared to other cruciferous vegetables) has a particularly powerful type of sulforaphane, which researchers believe gives broccoli its particular cancer-fighting properties.

It appears that broccoli contains the necessary ingredients to switch ON genes that prevent cancer development, and switch OFF other ones that help it spread, effectively delivering a double dose of protective action.

The power of food in normalizing chronic disease and helping you achieve optimal health is quite profound and one of the reasons that I chose a career of natural health.

How Many Vegetables Do You Have to Eat to Reap These Benefits?

Previous studies have indicated that people who consume more than one portion of cruciferous vegetables per week are at lower risk of prostate cancer. In the PLoS study mentioned earlier, the participants ate four extra servings of broccoli per week for one year.

The researchers collected tissue samples over the course of the study and found that the men who ate broccoli showed hundreds of beneficial changes in genes known to play a role in fighting cancer!

That’s pretty impressive. What’s even more impressive is the fact that you don’t have to make that drastic of a change to reap the benefits. After all, one serving of broccoli equates to about two spears. So we’re only talking approximately 10 spears a week, folks. That’s it!

Is Broccoli the Right Choice for You?

While I believe foods, especially vegetables, are a far smarter choice to treat serious health challenges like cancer than using most drugs, all foods may still not be the right choice for you. And even though vegetables are one of the healthiest food categories on the planet, not all vegetables are beneficial for everyone.

This is where a deep appreciation of nutritional typing will assist you in selecting the best vegetables for you.

One of the most serious mistakes is for a protein type to consume many dark green vegetables. This tends to over-alkaline your system and worsens rather than improves your health if you’re a protein type. This is despite the many beneficial phytonutrients that are present.  I am very familiar with this mistake as it’s one that I made prior to understanding nutritional typing.

However, other cruciferous vegetables such as cauliflower, which happen to be beneficial for protein types, can also have a similar effect.

I want you to be aware of just how important it is to understand your body at a deeper level, because if you are a protein type and were to eat broccoli, the other effects of broccoli might push your metabolic biochemistry in the wrong direction and thus override its benefits.

I also want to mention that small quantities of fresh broccoli sprouts contain as much cancer protection as larger amounts of the mature broccoli, according to previous research at Johns Hopkins University.

Just 5 grams (0.17 ounces) of sprouts contain concentrations of the compound glucoraphanin (a precursor to sulforaphane) equal to that found in 150 grams (5.2 ounces) of mature broccoli! The sprouts are eaten raw, usually as an addition to salad, and are a great way to get lots of cancer-protecting nutrients into your diet.

More Guidelines to Help Avoid and Treat Common Cancers

As I am now in Hawaii for the winter, I want to remind you of perhaps the most powerful cancer-prevention method available to all: sunshine!

Lately I’ve written extensively about the phenomenal health benefits of vitamin D from appropriate sun exposure, and cancer prevention is heavily featured. For a recap, or to continue your investigation on this topic, please review my recently updated Vitamin D Resource page.

I also created a one-hour video lecture to clear up the confusion about this essential nutrient. If you have not seen it yet, I recommend you set aside some time to watch it. In it I’ve distilled much of the most recent research findings – and believe me, there’s a lot! – so that you can get a comprehensive overview in the shortest amount of time.

Other recommendations for how to avoid and treat common forms of cancer include:

    1. Control your insulin levels. Make certain that you limit your intake of processed foods.
    2. Get appropriate exercise. One of the primary reasons exercise works is that it drives your insulin levels down. Controlling insulin levels is one of the most powerful ways to reduce your cancer risks.
    3. Get appropriate amounts of animal-based omega-3 fats such as krill oil or fish oil, and reduce your intake of omega-6 oils.
    4. Eliminate sugar as much as possible as it’s been shown again and again that sugar feeds cancer.
    5. Have a tool to permanently erase the neurological short-circuiting that can activate cancer genes. Even the CDC states that 85 percent of disease is caused by emotions. It is likely that this factor may be more important than all the other physical ones listed here, so make sure this is addressed. My favorite tool, as you may know, is the Emotional Freedom Technique.
    6. Get enough high-quality sleep.
    7. Reduce your exposure to environmental toxins and sources of heavy metals.
    8. Boil, poach or steam your foods, rather than frying or charbroiling them.