Dear Mark: Ornish Strikes Again, Vitamin D from Light Boxes, and Kimchi and Cancer

KimchiAh, it’s good to be back in the saddle again. The challenge was a lot of fun – don’t get me wrong – but ultimately both you guys and I come here for the dispensation of musings and information and writings and discussion on health, fitness, and any other number of lifestyle topics. So, let’s get to it, shall we?

Today, we’re doing a roundup of three Dear Mark questions and answers. First, I address the latest insinuation from Dean Ornish that we’re all killing ourselves despite our weight loss, our fitness gains, our prescription reductions, our improved outlooks on life, and our elevated levels of general happiness and satisfaction. Next, I discuss whether or not those light therapy boxes designed to combat seasonal disaffective disorder and reset circadian rhythms will also help us generate vitamin D. And finally, I explore the research linking the intake of pickled vegetables like kimchi to gastric cancer. Let’s go:

Eating for Health, Not Weight

Could you please comment on the article at the link above?

Also, did you have a chance to research overmineralization theory of aging?




This isn’t the first time I’ve mentioned Ornish. Way back in 2007, I wrote about a study comparing the Ornish diet, the Atkins diet, the Zone diet, and the LEARN diet. I won’t get too deep into his criticisms of low-carb, high-fat (or should I say “high-protein”) diets, because they’re based on the very same studies that have been thoroughly ravaged across this and other blogs for the past few years. Like my piece on the connection between red meat and type 2 diabetes here, and Denise Minger’s piece on the connection between low-carb diets and heart disease in Swedish women here.

Instead, my main focus will be on Ornish’s claim that his diet is optimal, that his magic diet program can reverse atherosclerosis and result in weight loss that obliterates the cheeseburger-and-buttered-bacon-fueled opposition. He makes this claim a lot, and you hear about it all the time from other sources. What’s he talking about? Where is this coming from? Why, he must have an impressive personal archive of statistics from diet study after diet study in which patients were placed on the Ornish plan and didn’t just thrive, but became supernatural beacons of health. Right?

Not really. It all comes from a single study done on 35 people published back in 1998. Twenty people were randomly selected to receive the Ornish diet – a low-fat, vegetarian diet rich in fruits, vegetables, legumes, grains, and soybean products. They were also placed on a lifestyle modification program which had them exercise regularly, go to stress management training, stop smoking, and do psychosocial support group meetings. That was the experimental group. The other fifteen – the control group – were not counseled in this manner, instead being told to merely “keep listening to their physicians.” How did this all play out?

The experimental group was exercising five hours a week; the control group was exercising two and a half hours a week.

The experimental group was spending 87 minutes per week performing stress management techniques like meditation; the control group was spending less than five minutes a week doing it.

The experimental group lost almost 24 pounds after a year and managed to keep 12 of them off after five years. The control group lost little to no weight.

Sure enough, by the end of the study, the experimental group had reduced atherosclerosis. After five years, the experimental group had experienced 0.89 cardiac events per patient, while the control group had experienced 2.25 events per patient. Things definitely improved.

So, what was it? Was it the diet alone that improved the experimental group’s health, as Ornish loves to emphasize? Or could it be that the weight loss, the meditation, the stress reduction, the exercise, and the lack of smoking also played a role in improving their heart health?

We already know that weight loss improves health, and a recent study even suggests that the type of diet isn’t very important for improving the function of blood vessels so long as you’re losing belly fat on it. We know that meditation and stress reduction can lower hypertension and reduce mortality from heart disease (and it can even increase telomerase, which Ornish again says his diet is responsible for). We know that regular exercise fights heart disease. And everyone knows that smoking tobacco is a terrible choice (PDF) for patients with heart disease (and anyone else, really).

So why does Ornish feel the need to reduce the benefits of his program to the composition of the diet while deemphasizing and often failing to mention the other aspects of the lifestyle modification program he recommends?

Because if he didn’t, he’d have to acknowledge that other diets can work alongside “lifestyle modification,” even – or especially – diets that include ample amounts of animal fat and protein.

To sum up, Ornish’s program – the diet that leads to weight loss, the exercise, the stress reduction, and the cessation of smoking – clearly seems to work for improving heart health. But he hasn’t proven that the specifics of his vegetarian low-fat diet are the main reason, nor has he shown that a high-fat, low-carb diet would somehow negate the proven benefits of the non-diet lifestyle modifications.

And sorry, haven’t had time to look into the overmineralization theory yet. Thanks for the reminder, though!


Thank you for your website, I am starting out with the program and I have a question about sunlight and “wake lights,” specifically the Philips GoLITE Blu.

I work in theatre, a profession that is known for fast food and no sunlight, and I was recently diagnosed with narcolepsy. I have been using the GoLITE Blu to help try and regulate my sleep cycles and I was curious if you knew to what extent it helps with vitamin D production, particularly for days (or weeks) where I don’t get a lot of sun.



Hey John.

I like the wake lights. They’re great for normalizing your circadian rhythms and getting you more in tune with the ebb and pulse of the day. And while actual natural light is probably best and perhaps irreplaceable, the GoLITE Blu is a fantastic option for when you just can’t get outside to let your eyes perceive the real stuff. However, the wake light unfortunately does not help with vitamin D production. For vitamin D, you absolutely need to expose your skin to UVB rays, the kind generated by the sun.

There is a lamp that generates enough UVB to stimulate vitamin D production, designed by Dr. Holick, author of The Vitamin D Solution. If anything will work, that should. At $425, it’s a little steep, but if you want to generate vitamin D the natural way without sun, that’ll do it.

Let me know how it goes.

Hi Mark!

I love your blog and your book. I learn something new every time I drop by on MDA! Keep up the good work!

Since you promote fermented foods a lot on MDA, I wanted to ask you: is there such a thing as too much fermented food?

When my South Korean friend immigrated to my city, she introduced me to spicy cabbage kimchi. Since I share your love of all things fermented, I liked it from the start, although it was a bit spicy at first. Recently I discovered that it is incredibly delicious when fried in butter as a side dish or as a topping for a good chunk of meat. The butter mellows the spices and rounds out the tangy flavor.

My friend cautioned me, however, to exercise restraint. Apparently it is common knowledge in Korea that while a bit of kimchi every day keeps the doctor away, it is addictive, and too much kimchi increases one’s risk of colorectal cancer. I totally agree that kimchi can be addictive (especially with butter!), but I wonder about the cancer part. Kimchi refers to all fermented vegetables, not just the spicy cabbage westerners are familiar with, so it is not only about the spices. Some kinds of kimchi are traditionally prepared pretty mild, and most kinds of kimchi are prepared with or without spices according to the family tradition. For exemple, in my friend’s family, cabbage, green onion and bitter gourd are prepared spicy, while daikon, pumpkin and cucumber kimchi are prepared mild.

Do you think there is such a thing as too much fermented foods? Should I cut back if I find myself eating something fermented at almost every meal? Are the abundant spices of the Korean cuisine to blame rather than the kimchi? Or do you think this is all Korean Conventional Wisdom, full of good intentions but full of flaws?

Thank you for your insight!


Thanks for the compliments!

It’s true that kimchi has been linked in several observational studies to cancer, but not colorectal cancer. It’s actually stomach, or gastric, cancer that’s primarily associated with kimchi intake. To get an idea of what they’re talking about, take a look at one of the latest of these studies, a 2009 meta-analysis entitled “Fresh and pickled vegetable consumption and gastric cancer in Japanese and Korean populations: A meta-analysis of observational studies.”

I think there are a few possible explanations for this:

  • Note that the highest levels of pickled vegetable intake are associated with stomach cancer, meaning that people who are eating the most kimchi are probably eating less fresh vegetation, simply because they run out of “room” in their diets for the fresh stuff. Furthermore, intake of non-fermented vegetables like cabbage and other cruciferous vegetables, garlic, onion, and allium vegetables in general are often inversely associated with stomach cancer, and if you’re eating a bunch of fermented cabbage, you’re probably not going to include a significant amount of non-fermented cabbage and other vegetables, too.
  • Kimchi, even homemade stuff, has been shown to form significant amounts of nitrosamines when subjected to “simulated human stomach conditions.” Dietary nitrosamines have been linked to several cancers, including gastric, but I’m not sure how realistic those simulated stomach conditions actually are.
  • Atrophic gastritis, a type of chronic inflammation of the stomach mucosa, can increase the risk of developing stomach cancer; atrophic gastritis is often caused by a helicobacter pylori infection. The presence of large amounts of salt in the stomach (like from a meal of pickled vegetables) has been linked to an increase in the virulence of h. pylori. Since h. pylori infection is far more common in Korea, perhaps a high intake of salty pickled vegetables makes the already-present h. pylori more virulent, which leads to more atrophic gastritis and, eventually, gastric cancer.

But that’s not the entire picture:

Confusing, huh? If any lesson can be gleaned from this, it’s to treat fermented vegetables, including kimchi, as a condiment. Also, you’ll want to make sure that your fermented vegetable intake does not replace your fresh vegetable intake. Fresh veggies should provide bulk and volume to your meals, while fermented vegetables should act as adornments and meal enhancers. Treat fermented and fresh vegetables like you treat cured meats and fresh meats; as delicious as bacon is, you don’t want it to comprise the majority of your meat intake.

To answer your questions:

  1. There’s probably such a thing as too much fermented food, but I don’t have a hard number for you. It’s “too much” when it begins to crowd out fresh vegetable intake.
  2. Eating something fermented at every meal should be fine so long as it’s – once again – not the only way you’re eating vegetables.
  3. Spices are almost uniformly healthy, especially since these are homemade ferments without added MSG and other junk masquerading as “spices.”
  4. It’s always worth investigating traditional advice about health and nutrition, in my opinion, because there’s often some wisdom lurking there.

Oh, and avoid radish kimchi at all costs or risk certain death!

Just kidding. Thanks for reading, folks.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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