By Dr. Mercola
Nearly 23 percent of Americans report consuming vegetables and fruits less than one time daily, with a median vegetable intake of just 1.6 times per day overall.1 In contrast, experts recommend consuming five to nine servings of vegetables and fruits daily for optimal health.
Chances are you know vegetables are good for you, and perhaps you've been meaning to include more of them in your daily diet. If you're looking for motivation, the latest research adds to considerable evidence that eating veggies lowers your risk of many types of cancer.
In a recent study by researchers with the University of Missouri in Columbia, it was further revealed that eating vegetables may lower your risk of breast cancer due to a beneficial compound called luteolin.
Luteolin in Celery May Lower Breast Cancer Risk
Luteolin is an anti-inflammatory plant compound found in certain vegetables, including celery, peppers, and carrots. It's previously been linked with lower rates of age-related memory loss in mice.2
And now researchers have found it may slow the development of breast cancer – particularly that caused by hormone replacement therapy (HRT).
In the past, hormone replacement therapy (HRT) was widely prescribed for treating menopausal symptoms and even for preventive purposes, based in part on early observational studies that had suggested it could help protect women against heart disease, weak bones, as well as dementia.
All of that changed in 2002, when the 15-year Women's Health Initiative (WHI) abruptly ended its combination of estrogen and progestin therapy study because their data revealed higher rates of breast cancer, heart attacks, strokes, and blood clots in the population taking the hormones compared to those receiving a placebo.
Researchers from the featured study explained that benign lesions in breast tissues may turn into tumors if they received a "trigger" such as progestin, which attracts blood vessels and "feeds" the lesions, allowing them to expand.
When this occurs, the breast cancer cells "take on stem cell-like properties, which can make them harder to kill," the study's lead researcher stated.3 However, when breast cancer cells were exposed to luteolin in the lab, their viability markedly decreased.4
Not only did the blood vessels feeding the cells decline significantly, but also their "stem cell-like properties" were reduced, resulting in an anti-tumor effect. The researchers then tested luteolin on mice with breast cancer and similar benefits were observed.
The researchers are hoping to develop a luteolin-based drug that could be injected into the bloodstream to fight aggressive and hard-to-treat forms of breast cancer.
However they suggested that, in the meantime, women continue eating plenty of fruits and vegetables. In addition to celery, peppers and carrots, luteolin is also found in thyme, parsley, and broccoli.
Lycopene: Another Cancer-Fighting Compound in Veggies
Lycopene — a carotenoid antioxidant that gives fruits and vegetables like tomatoes and watermelon a pink or red color – has long been identified as a cancer fighter, although most often it's mentioned in relation to prostate cancer.
Research shows, however, that lycopene may reduce breast cancer risk as well and may be particularly promising for those with difficult-to-treat estrogen receptor (ER)–negative tumors.
Lycopene's antioxidant activity has long been suggested to be more powerful than other carotenoids such as beta-carotene and research published in the Journal of the National Cancer Institute also found lycopene to be the most effective carotenoid in reducing breast cancer risk.5
The meta-analysis, which comprised more than 80 percent of the world's published data on blood levels of carotenoids and breast cancer, revealed women with the highest level of total carotenoids had a 19 percent lower breast cancer risk compared to those with the lowest levels.
It's clearly beneficial to consume a wide variety of vegetables that contain various carotenoids, but if you're looking for the one with the greatest cancer-fighting potential of all, lycopene came out on top. News at JAMA reported:6
"Women with the highest levels of lycopene had a 22 percent decreased breast cancer risk; those having the highest beta-carotene levels had a 17 percent decreased risk.
Women with the highest levels of lutein and zeaxanthin (levels were read together) had a 16 percent reduced risk; and those with the highest levels of alpha-carotene had a 13 percent reduced risk compared with women having the lowest levels.
… The researchers said carotenoids may have several avenues available to reduce breast cancer risk. They are metabolized to retinol, which in turn regulates cell growth and differentiation and programmed cell death. Carotenoids also may enhance immune system functioning or help mop up oxygen-reactive species that cause cell damage."
If you eat right, it should be relatively easy to get therapeutic levels of lycopene in your diet. Cooked tomato-based foods, such as organic tomato sauce, tomato paste, and spaghetti sauce, are among the best dietary sources of lycopene. It's also abundant in watermelon.
Sulforaphane: The Cancer-Fighting Broccoli Superstar
No discussion of the cancer-fighting powers of vegetables would be complete without a mention of sulforaphane, an organic sulfur compound found in cruciferous vegetables, including not only broccoli but also Brussels sprouts, cabbage, cauliflower, horseradish, and arugula.
Broccoli sprouts are actually the richest source.
Sulforaphane kills cancer stem cells, which slows tumor growth. This sulfur compound also normalizes DNA methylation, which plays a role in a number of diseases, including hypertension, kidney function, gut health, and cancer.
Sulforaphane also increases enzymes in your liver that help destroy cancer-causing chemicals you may consume or be exposed to in your environment. This compound has even been called "one of the most powerful anti-carcinogens found in food."7
Drug company Evgen has even developed the so-called "broccoli pill" (Sulforadex), which consists of a stabilized form of sulforaphane. Ordinarily, sulforaphane is highly unstable and must be kept at minus 20 degrees F.
Evgen reportedly stabilized the compound in a way that protects its efficacy, and says to get the benefits that the pill provides you'd need to eat about 5.5 pounds of broccoli a day.
Sulforadex has already been found to lower the risk of cancer, slow cancer growth, and stop its spread in animal studies, and it has been tested on 47 volunteers with promising results.8 Additional clinical trials are in the works with the hope the pill will work to treat brain hemorrhage and breast and prostate cancers.
Remember, however, that you can get sulforaphane via your diet by eating broccoli, broccoli sprouts, and other cruciferous vegetables, and when you do this you're also getting additional cancer-fighting, health-boosting nutrients found in these vegetables (like diindolylmethane, or DIM, which boosts your immune system and helps to prevent or treat cancer).
The 'Trick' to Maximizing the Sulforaphane in Your Broccoli
Sulforaphane is formed when you chop or chew broccoli (this combines its precursor glucoraphanin and the enzyme myrosinase).
Once swallowed, your gut bacteria may then help to release some of broccoli's sulforaphane so your body can benefit, but it's a tricky proposition because sulforaphane is attached to a sugar molecule with a sulfur bond.
As reported by Science Daily:9 "When the broccoli enzyme breaks off the sugar to release the sulforaphane, a sulfur-grabbing protein can remove the newly exposed sulfur on the sulforaphane and inactivate it." Researchers have found that one of the best ways to maximize sulforaphane your body can use is to heat the broccoli for 10 minutes at 140 degrees Fahrenheit (or steam it lightly for three to four minutes until it's tough-tender).10
This was just enough heat to kill the epithiospecifier protein, which was "grabbing the sulfur" and "greatly depleting the amount of sulforaphane in a serving of broccoli."11 Another option is to eat broccoli sprouts. Fresh broccoli sprouts are FAR more potent than whole broccoli, allowing you to eat far less in terms of quantity.
For example, tests have revealed that three-day-old broccoli sprouts consistently contain anywhere from 10 to 100 times the amount of glucoraphanin – the precursor to sulforaphane – found in mature broccoli.12 Perhaps better still, research showed that broccoli sprouts enhanced the absorption of sulforaphane when consumed along with a broccoli powder, and broccoli sprouts alone had the highest absorption rate of all (74 percent).13
Eating Enough Vegetables Lowers Your Risk of Cancer and Premature Death
As mentioned, eating vegetables isn't only important for reducing your risk of breast cancer. This is one health habit that can lower your risk of multiple types of cancer as well as your risk of numerous chronic diseases. One study found:14
- Those who ate five to seven servings of vegetables and fruits per day had a 36 percent lower risk of dying from any cause
- Three to five servings was associated with a 29 percent lower risk
- One to three servings was associated with a 14 percent lower risk
But perhaps most strikingly of all, people who ate seven or more portions of vegetables and fruit a day had a 42 percent lower risk of dying from any cause, compared to those who ate less than one portion. They also enjoyed a 31 percent lower risk of heart disease and a 25 percent lower risk of cancer. Vegetables had a larger protective effect than fruits.
So while consuming small amounts of whole fruit is fine (and even beneficial) if you're healthy, your focus should be on vegetables. When broken down by vegetables only, each additional daily portion of fresh veggies lowered participants' risk of death by 16 percent compared to 4 percent for fresh fruit.
The fact of the matter is vegetables contain an array of antioxidants and other disease-fighting compounds that are very difficult to get anywhere else. Plant chemicals called phytochemicals can reduce inflammation and eliminate carcinogens, while others regulate the rate at which your cells reproduce, get rid of old cells and maintain DNA. Vegetables are also one of the best forms of dietary fiber. Studies have repeatedly shown that people with higher vegetable intake have:
Lower risks of stroke, type 2 diabetes, high blood pressure, Alzheimer's disease, and heart disease Lower risks of certain types of cancer, eye diseases, and digestive problems Reduced risk of kidney stones and bone loss Higher scores on cognitive tests Higher antioxidant levels Lower biomarkers for oxidative stress
Which Vegetables Are Best?
It's hard to go wrong when eating vegetables, especially if you choose those that appeal to you. However, if you want to take your health up a notch, opt for vegetables that are locally grown, organic, and in season. This will ensure you're getting the freshest vegetables without added toxins, like pesticides.
Growing your own vegetables is one of the best ways to get inexpensive fresh produce. Replace your lawn or shrubs with a vegetable garden — just be careful about your local zoning laws – or use containers. If a garden is not feasible, join a local food coop or frequent farmers' markets (many of these now accept food stamps, too).
Generally speaking, you can eat as many green leafy vegetables as you want while high-sugar vegetables (like beets and carrots) should be eaten in moderation. My recommended list of vegetables provides a guide to the most nutritious vegetables, and those to limit due to their high carbohydrate content.
If you want more details about the specific nutrients and health benefits of different veggies, we've compiled an extensive review of the health benefits of vegetables in our Mercola Food Facts Library. However, as a general guide, the following list of vegetables details some of the best and worst vegetables for your health.
Highly Recommended Vegetables Asparagus Escarole Avocado (actually a fruit) Fennel Beet greens Green and red cabbage Bok choy Kale Broccoli Kohlrabi Brussels sprouts Lettuce: romaine, red leaf, or green leaf Cauliflower Mustard greens Celery Onions Chicory Parsley Chinese cabbage Peppers: red, green, yellow, and hot Chives Tomatoes Collard greens Turnips Cucumbers Spinach Dandelion greens Zucchini Endive
Use sparingly due to high carbohydrate levels Beets Jicama Carrots Winter squashes Eggplant
Vegetables to Avoid Potatoes Corn
Creative Ways to Add More Vegetables to Your Diet
Make it a point to include vegetables with every meal – a salad, a side dish, or as a pre-meal snack – or make veggies the main focus of your meals. Keep fresh veggies on hand, too, so you'll always have some to snack on or add to whatever you're cooking. You'll easily work your way up to seven or more servings a day.
When preparing your veggies, use quick, gentle cooking methods (only cooking to a tender-crisp, not mushy, texture) to preserve the most nutrients. Also try to eat a good portion of them raw, which will allow you to receive beneficial biophotons. Two of the best ways to get more raw vegetables into your diet include:
- Juicing: Juicing allows you to absorb all the nutrients from vegetables, allows you to consume an optimal amount of vegetables in an efficient manner, and makes it easy to add a variety of vegetables to your diet.
- Sprouts: The sprouting process tends to increase nutrient content and bioavailability of nutrients. Sprouts also contain valuable enzymes that allow your body to absorb and use the nutrients of all other foods you eat. They're very easy to grow at home.
Some of the healthiest vegetables are also among the least expensive. Take cabbage, which you can eat on its own or use as a base for fermented vegetables. Fermenting is one of the best ways to turn ordinary vegetables into superfoods, and you can produce gallons of fermented vegetables for just a few dollars. Fortunately, the more vegetables you eat, the better you'll likely feel and the more vegetables you'll crave, making it easier and easier to add them to your diet.