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Remember the Fab Four?

No, I’m not talking about the Beatles.

But the “Four Foods” that are crucial to a healthful plant-based diet and lifestyle.

To refresh your memory, the Four Foods are:

  1. Beans (for their micronutrients and phytochemicals and for their protein and fiber).
  2. Greens (also for their micronutrients, phytochemicals and fiber).
  3. Berries (for their phytochemicals and antioxidants).
  4. Seeds (for their omega-3 fatty acids and phytochemicals).

Last week, we talked about the often forgotten but oh-so-important Brilliant Bean.

Today I’d like to turn to the topic of Greens and take a closer look at why they are a veritable machine when it comes to health promotion.

Why Mom Was Right

Since we were all little, we’ve been told of the wonders of ‘eating our greens’.   There’s a good reason why.

Greens can improve eyesight, immune function, athletic performance, and even physical appearance. They should be eaten every day.

Plus doctors have long believed that eating greens can also play an important role in preventing cancer. One of the reasons is that chlorophyll, the green pigments in plants, appears to intercept carcinogens in the body.

There’s More Than One Category of Green…

Before we go farther into our discussion about greens, it’s worthwhile pointing out that when we talk about ‘greens’, two informal categories seem to shine: dark leafy greens and cruciferous vegetables.

Dark leafy greens include vegetables like spinach, kale, watercress, beet greens, mustard greens, collard greens and arugula.

Cruciferous vegetables include greens like broccoli, kale, green cabbage, cauliflower, bok choy, collard greens, and Brussels sprouts.  The cruciferous vegetables get their name because their four-petal flowers resemble a cross or ‘crucifer’.

Obviously, these two categories can become blurred; many vegetables (like kale and collard greens) fall into both groups.

In this article, we will concentrate largely on the health benefits of the cruciferous vegetables.  

Here are the top three benefits:

  1. Cruciferous vegetables stimulate gut health

Doctors have known for a long time that the Western diet puts people at higher risk of inflammatory bowel diseases like ulcerative colitis, while higher vegetable intake is associated with a lower risk.

Simply put, the immune cells in our intestines are greatly aided by plant-derived phytochemicals.  And cruciferous vegetables are key providers of a phytonutrient that is transformed by stomach acid to activate our “immune foot soldiers”.

So at the end of the day, your gut NEEDS cruciferous veggies to maintain a large population of those protective cells and support your immune system.

  1. Cruciferous vegetables protect against DNA damage

Cigarette smoke has substances that can cause damage to DNA; cruciferous vegetables contain phytochemicals with antioxidant properties that can protect against that damage.

A study of smokers revealed the remarkable power of a single stalk of broccoli. During the study, those who ate just one stalk of
broccoli a day for 10 days suffered 30% less DNA damage than smokers who ate none.

But that does not mean you can continue to smoke if you eat broccoli! Other studies suggest that smoking depletes the antioxidant nutrients you ingest with food and will lead to a higher risk of stroke, heart disease and cancer.

  1. Cruciferous vegetables help fight and prevent cancer  

Over the last decade, scientists studying the spread and recurrence of cancers have focused on tumor stem cells. The new data suggests a new approach; instead of taking aim directly at the tumors, why not target the cancer’s stem cells?

High intake of fruits and vegetables, along with physical activity, has been shown to quadruple the survival rate of breast cancer patients, while specific intake of cruciferous vegetables may cut the risk of breast cancer recurrence in half.  The sulforaphane in broccoli seems to be the answer. Studies show that the compound can destroy cancerous stem cells and it might even prevent cells from becoming cancerous in the first place.

But broccoli is not alone in its cancer-fighting abilities. Spinach (a dark leafy green vegetable) and other cruciferous vegetables like cabbage and cauliflower are famous for being anti-cancer superstars. And kale can boost your immune system whether you eat it cooked or raw.

Is There Such a Thing As “Too Many Greens”?

Many ask if it is possible to ‘overdo’ your greens.

The answer is equivocal–yes and no.

There are compounds in raw cruciferous vegetables that may interfere with thyroid function if people aren’t getting enough iodine in their diet. The answer? Make sure you are getting enough iodine in your diet (sea vegetables are a great source) and you might also want to consider cooking cruciferous veggies instead of eating them raw.

What About Green Smoothies?

I can’t possibly talk about the subject of greens without mentioning green smoothies.  Here’s my take on the ‘good, bad and beautiful’ when it comes to green smoothies.

  • The good:  One of the greatest benefits of green smoothies is that they are the absolute easiest way for many people to increase their daily greens intake and maximize phytochemical absorption in the gut. The reality is that you could never chew well enough to release all the nutrition in your greens.  Smoothies take the “work” out of it — making all the good stuff readily available for your body to use.

And the more greens you can throw in that blender the better!. And don’t stop at ‘just’ smoothies; think about also blending green veggies into soups and sauces as well.

  • The bad: Because you drink a smoothie, the meal duration is shorter, so your body won’t ‘signal’ that you’ve taken in enough calories. The answer is to drink your smoothies slowly instead of gulping them on the run. Plus, adding flax seeds increases satiety and thickens the mix to help slow down consumption (and you’ll get some omega-3 fatty acids to boot).
  • The beautiful: If you find your green smoothie to be too bitter, you can combine fruit in. Blending berries and/or bananas (NOT apples) into a green smoothie will not just add natural sweetness–it might actually improve blood sugar control. By blending two of the Four Foods (berries + greens) together, you get greater nutrient absorption without risking rapid sugar absorption. Win-win.

The green machine is unstoppable.  However you eat them–cooked, raw, blended or mashed–Mom was right.  Greens are nature’s great gift to us–a health-promoting powerhouse that will boost your immune system and protect you from cancer.

Rosane Oliveira, DVM, PhD

President & CEO, Plant-Based Life Foundation | Dr. Rosane Oliveira combines a lifelong passion for nutrition with 25 years of genetics research to create programs that help people develop healthy habits on their journey towards a more plant-based lifestyle. She is a Visiting Clinical Professor in Public Health Sciences and was the founding director of the first Integrative Medicine program at the UC Davis School of Medicine. She completed her postgraduate studies in Brazil and did her postdoctoral training in immunogenetics and functional genomics at the University of Illinois at Urbana-Champaign.