Almost three hundred case-control studies show that vegetable consumption provides a protective effect against cancer and that cruciferous vegetables are the foods with the most powerful anticancer effects of all foods. Cruciferous vegetables are those in the broccoli and cabbage family and include such foods as bok choy, radishes, and watercress. While eating fresh fruits, beans, vegetables, seeds, and nuts have been all been shown in scientific studies to reduce the occurrence of cancer, cruciferous vegetables are different. Instead of a one-to-one relationship against cancer, they have a one-to-two relationship with a wide variety of human cancers. In other words, as plant food intake goes up 20 percent in a population, cancer rates typically drop 20 percent. But as cruciferous vegetable intake goes up 20 percent, cancer rates typically drop 40 percent.
Cruciferous vegetables contain phytochemicals that have a unique ability to modify human hormones, detoxify compounds, and prevent toxic compounds from binding to human DNA, thus limiting toxins from causing DNA damage that could lead to cancer. Sulforaphane, an extensively studied compound, is an isothiocyanate that has a unique mechanism of action. This compound blocks chemical-initiated tumor formation and induces cell cycle arrest in abnormal cells, meaning it inhibits growth and induces cell death in cells with early cancerous changes in a dose-dependent manner. Recent studies show that the amount of sulforaphane that can be obtained from eating a reasonable amount of broccoli can have dramatic effects to protect against colon cancer.
Most micronutrients that we read about (vitamin C, vitamin E, beta-carotene, lutein, lycopene) function as antioxidants in the body, meaning these compounds neutralize free radicals, rendering them harmless. But the phytochemicals in cruciferous vegetables do more. They enable the body’s own antioxidant control system. When we take in direct antioxidants such as vitamin C and E, they fight a one-on-one war against free radicals but not much more. Their effects are gone in a few hours. Synthetic or isolated fractions of vitamin E, beta-carotene, or vitamin C can also cause pro-oxidant behavior, creating more free radicals. So instead of having a short-lived benefit that gets used up quickly, the unique compounds in cruciferous vegetables cycle over and over, protecting the body for three to five days after consumption. They fuel body systems already in place so that they function more effectively, but they also induce many different systems to defend against many different types of damage.
- Repair and protect
- Detoxify toxins and carcinogens, rendering them harmless
- Regulate the liver’s ability to remove toxins
- Remove free radicals to prevent oxidative and DNA damage in cells
- Transform hormones into beneficial compounds that inhibit hormone-sensitive cancers
- Enhance and protect against age-related loss of cellular glutathione
- Enable cell death in cells that have abnormal mutations and DNA damage
A study on prostate cancer shows that it takes twenty-eight servings of vegetables a week to decrease the risk of prostate cancer by 33 percent, but just three servings of cruciferous vegetables a week decreases the risk of prostate cancer by 41 percent. The National Cancer Institute of the National Institutes for Health recommends nine servings of fruit and vegetables per day. I recommend eight servings of vegetables a day, with at least two of those being cruciferous vegetables, one raw and one cooked. Do you eat green cruciferous vegetables daily? Do you eat both raw and cooked green vegetables? Let’s all make sure we do.
Greens and Heart Disease
Heart disease is caused by the buildup of fatty plaques in the arteries, known as atherosclerosis. However, arteries do not get clogged up with these plaques in a uniform way. Bends and branches of blood vessels—where blood flow is disrupted and can be sluggish—are much more prone to the buildup. A recent study shows that Nrf2, a protein that usually protects against plaque buildup, is inactive in areas of arteries that are prone to disease. However, a phytochemical found in green vegetables activates Nrf2 in these disease-prone regions. Activation of Nrf2 is important for maximizing both prevention and removal of plaque. Ingestion of these beneficial compounds from cruciferous green vegetables had the strongest effect to activate the Nrf2 proteins, blocking atherosclerosis.
Vegetables have other powerful disease-fighting nutrients as well. Carotenoids are just one compound that is important for excellent health. Greens have high levels of carotenoids and other nutrients that prevent age-related diseases that diabetics are prone to. For example, the leading cause of age-related blindness in America is macular degeneration. If you eat these greens at least five times per week, your risk drops by more than 86 percent. Lutein and zeaxanthin are carotenoids found in green vegetables with powerful disease-prevention properties. Researchers have found that people with the highest blood levels of lutein had the healthiest blood vessels, with little or no atherosclerosis.
Of course, losing body fat, lowering glucose levels, and lowering blood pressure all play an important role in the prevention and reversal of heart disease. But the message here is that a diet rich in greens protects against diabetes, aids in weight loss, and fights cancer, in addition to enabling more targeted and effective reversal of high blood pressure and heart disease.
And green vegetables are so incredibly low in calories and rich in nutrients and fiber that the more you eat of them, the more weight you will lose. I am going to stop here and highlight this point.