Friday Favorites: The Benefits of Kale and Cabbage for Cholesterol

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

LDL “bad” cholesterol is bad, but oxidized LDL may be worse. What role might our diet play? “Increased fruit and vegetable consumption has been reported to reduce the risk of developing [cardiovascular disease, heart attacks, and strokes].” Well, maybe it’s in part because of all the antioxidants in healthy plant foods preventing the oxidation of LDL cholesterol. And, indeed: “The LDL oxidation resistance was [found to be] greatest” among those eating more plant-based. So, that would be “in addition to the decreased blood pressure” and lower LDL overall in terms of “beneficial effect[s].” But, you don’t know if it’s cause and effect, until you put it to the test. Put people on a whole-food plant-based diet for just three weeks, and rates and extent of LDL oxidation drop.

“The effects of kale” on LDL oxidation were put to the test. Kale is a best-of-all-worlds food, low in calories and packed to the hilt with nutrition—vitamins, minerals, anti-inflammatory compounds, antioxidant phytonutrients—you name it. No surprise, then, given its “high antioxidant capacity… kale showed a protective effect on the oxidation of [LDL] even at low concentrations.” But, this was in vitro, in a test tube. Kale was also put to the test in mice. But, what about people?

I did a video on this study, on how “kale juice improves coronary artery disease risk factors in men with high cholesterol].” Extraordinary results: a 20% drop in LDL among the nonsmokers. But, they were drinking the equivalent of about 10 cups of kale a day. Still, the fact that they were able to see such an improvement, even though nearly all the fiber was removed, because it was just juice, shows there does seem to be something special in the plant. But, can you get the benefit just eating the stuff? Let’s find out.

“The effect of black and red cabbage on…oxidized [LDL].” And by black cabbage, they mean lacinato kale, also known as dinosaur or Tuscan kale. They had people eat a bag of frozen kale and cabbage a day for just two weeks—which is great because you can just keep it in the freezer, pre-washed, pre-chopped, and just throw it in any meal you are making—and got “significant reductions” of total cholesterol, LDL cholesterol, and even blood sugar levels. And, the antioxidant capacity of their blood went up. So, no surprise, they demonstrated “a significant decrease” in oxidized LDL, too.

Would it have been better to take that red cabbage and ferment it into sauerkraut? Red or purple cabbage is one of my favorite vegetables—packed with antioxidants, yet dirt cheap, and seems to last forever in the fridge. It’s pretty, and juicy, and tasty. I try to slice shreds off into any meal I’m making. But, when you ferment it, not only do you add way too much salt, but you end up wiping out some of the nutrition. Here’s the big spike in antioxidant capacity of your bloodstream in the hours after eating fresh red cabbage—cut down by almost 30% if you ate the same amount in fermented form. Does cabbage have to be raw, though?

No. Some “[c]ooking techniques may improve the…antioxidant activity in kale and red cabbage.” “The effects of the cooking process can be positive, since cooking softens the vegetable tissues,” helping your body extract the active compounds. “However, cooking can also be negative, because heat treatment can degrade [some of the] compounds. They looked at a variety of different cooking methods, and concluded “steaming [may] be considered to be the best home cooking technique to prepare kale and red cabbage.” But with foods that healthy, the truly best way to prepare them is whatever way will get you to eat the most of them.

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• Fraser GE. Diet and coronary heart disease: beyond dietary fats and low-density-lipoprotein cholesterol. Am J Clin Nutr. 1994;59(5 Suppl):1117S-1123S.

Image credit: anandasandra via Pixabay. Image has been modified.

Motion graphics by Avocado Video.