A New Reason to Eat Greens

April 30, 2013 in Health Claims, Immune System, Mediterranean, Nutritionism, Uncategorized by Joyce Bunderson

Of course you know that eating dark green leafy greens is good for you; after all, your mom, your grandmother, Popeye and Dr. Grandma have all told you so. And certainly, let’s not forget Dr. Ancel Keys, who published his book, How to Eat Well and Stay Well the Mediterranean Way. Without doubt, owning a copy of the original publication is expensive, but plenty of people have based their new publications on Keys research, which he and his colleagues did in 7 countries. He did his research in the late 1950s and early 1960s; and clear back then, it was a radical idea that the risk of coronary heart disease (CHD) was greatly influenced by what was served at mealtimes.

Keys not only focused upon the intake of greens, but other dietary and lifestyle differences between the Western diet and the Mediterranean peoples (like the use of olive oil; fish; whole grains; wine; and little meat, cheese and sugar). Because of new scientific work and publication, today I want to focus on just the ‘greens’ portion of Keys work.

Keys described the intake of greens by the Mediterranean peoples by stating, "No main meal in the Mediterranean countries is replete without lots of verdure (greens)." He added that the greens are often prepared with virgin olive oil, which itself is an additional source of antioxidants.

When researchers write that they have observed populations, like Ancel Keys did over six decades ago, what science says is that it doesn’t really prove that the Mediterranean Diet, for example is what caused the lower rate of CHD. The point is that when one thing (Mediterranean Diet) is associated (correlated in scientific or statistical terms) with another (lower CHD) it only shows association – not cause.  So what the researchers then have to do are controlled studies, to try to show cause. Controlled studies where one gets “the treatment” (like eating greens) and the other does not are very difficult and costly studies to administer.  But over the decades, some good research trying to work toward showing causation has been undertaken on the various factors in the Mediterranean Diet.

The somewhat easy part was learning what actually was in greens. Of course, the nutrients vary with the type of vegetable, but there are some nutrients that you can find in almost all greens. They are excellent sources of a wide array of vitamins and minerals, so naturally among the first guesses were vitamin C and beta-carotene. And also it seems almost natural that after learning the benefits of greens, that the early pioneers of Big Pharma would encourage taking tablets of vitamin A, or beta-carotene, and vitamin C – and be sure to take lots.

As time when on, and the examination of greens continued, more ideas surfaced – especially after the association with a decreased risk of certain cancers was also associated with intake of greens. So other attributes of greens were considered. Could it be their calcium, iron, or fiber content? Or could it be the fact that they’re often loaded with potassium and are low in calories and sodium; and are essentially free of fat and cholesterol? Yes, those of you that have read this blog for a while know that this is another great example of nutritionism – trying to attribute the consistently high health scores of greens to one player, one kind of molecule, rather than to the whole team of nutrients.

Why would the public turn to vegetables, Yucky! – when you can have a few little tablets (comparatively costly and profitable) fiber supplements and a handful of vitamins and minerals. Who cares about the hundreds of phytonutrients that don’t yet come in a supplement?

Let me tell you about some new research – cutting edge research by Lucille C. Rankin et. al published in Nature Immunology; it adds an entirely new reason for actually eating greens. The researchers have discovered that innate lymphoid cells (ILCs responsible for producing the hormone interleukin-22) help protect the body from harmful bacteria in the intestine. These cells are found in the lining of the digestive system. Humans have a gene called T-bet and it is essential for producing the ILCs that protect our body from the harmful bacteria. The T-bet genes respond to signals from the food we eat.

When we eat greens, the proteins from the greens interact with the cell surface receptors that turns on the production of T-bet and that in turn starts the production of the ILCs that produce the interleukin-22, which protect you from the harmful bacteria. In essence, they learned one of the specific roles of leafy greens, which seem to play an important part in controlling food allergies, inflammatory diseases, obesity, and even bowl cancers.

For most of us, the take away lesson is: Our bodies have it under control. If we supply the right substrate (the greens) then these fairly complex chemical reactions will happen automatically. It’s pretty easy – EAT GREENS!

The great news is that ‘greens’ is not a small category of vegetables; Wikipedia has a huge list of green veggies. But to get you started maybe you could consider easy greens to find. Denise Reynolds RD included the following alphabetic list of some greens in her March 4, 2013 article A New, Very Important Reason to Eat Leafy Green Vegetables. Dark leafy greens include arugula, beet greens, Belgian endive, broccoli, bok choy, cabbage, collards, curly endive, dandelion greens, escarole, kale, lettuces, mustard greens, radiccho, rapini (broccoli rabe, broccoletti), spinach, Swiss chard, turnip greens and watercress. A couple of others to add to her list are artichokes, asparagus, basil, broccoflower, Brussels sprouts, celery, cilantro, endive, fennel, leeks, and parsley.

In the Denise Reynolds article you can click on above, she shares some ways to use greens. A few additional ideas are: to make my Green Basil Hummus in the Journey Away from Sugar article; Reverse omelets; add chopped greens to marinara sauce and serve over pasta or in recipes like stuffed peppers etc; process excess frozen greens from spring/summer harvest in blender and use as soup base. I’ve been using radish tops that are frozen and blended to liquid bits in soup; along with some herbs, it increases the flavor and allows for a decreased use of salt – this is definitely a win-win.

Certainly there are hundreds of ways to create healthy delicious meals using greens. You don’t need to remember the entire biological pathway to make more interleukin-22 in your own tummy. All you have to do to benefit is to get the greens down into the tummies of you and your family; ideally with the blessings of happy taste buds because you made it taste yummy. Then the greens and the tummies will do their part to produce the good byproducts that lead to healthy and happy lives.