What the HealthAs I expected, I received quite a few emails related to my column in Sunday’s Seattle Times on the documentary “What the Health?” Rather than answer the emails individually, I’m turning them into this admittedly rather loooong blog post. Without further ado:

On Environmental Impact…

One important thing that I don’t find in your review: the amt. of water it takes! “…to produce one pound of beef is 1,799 gallons of water; one pound of pork takes 576 gallons of water. As a comparison, the water footprint of soybeans is 216 gallons; corn is 108 gallons.”

I didn’t include water use in my review because I couldn’t touch on every point in the film…I only had 1,000 words to use (for perspective, this blog post is running at 1,805. My dietitian friend Chris Vogliano, MS, RDN, is very knowledgeable about the environmental impact of our food choices, and is in fact going to be working even more deeply on sustainability issues soon when he begins work on his PhD soon. When I asked him to comment on the film, I let him choose the points he wanted to comment on.

It’s true that it takes a lot of water to produce livestock, but I don’t know that the corn and soybean comparison is a good one, since we can only eat so much corn and soy, and some of that may be going right back into livestock feed. I think it’s noteworthy that some agricultural crops have come under fire for being water hogs, and when I was at a conference in Phoenix recently, I learned that they have no shortage of water, now that there is less agriculture and fewer crops needing irrigation (that totally surprised me). In any case, water usage is a very complex issue, and it is one that deserves attention, since without water we die.

(For more on the role of sustainability in nutrition—as well as what experts from differing nutrition POVs agree on—see my Seattle Times column, “Vegan, Paleo, low fat—They all have something in common.”)

On Other Documentaries…

Have you seen “Forks Over Knives”?

Yes, I saw “Forks Over Knives” when it came out in the theaters (in a blast from my blogging past, this is what I had to say about it at the time). I remember thinking “This is awesome,” until the film reached the point where they were stretching their message too far (i.e., they were making some claims that aren’t quite supported by science). However, I did not have the same negative reaction from that film as I did from “What the Health?” What both films get wrong is pushing the idea that the only healthy diet for every person is a vegan diet. Vegan diets work beautifully for some people, but not for everyone. Nutrition is not black and white.

On Health Benefits…

Another reader took some issue with this quote from dietitian Ginger Hultin, MS, RDN, CSO: “Studies show that diets without meat are healthful, nutritionally adequate, and may provide health benefits for the prevention and treatment of certain diseases.” The reader went on to say: Aside from a limited number of people with GI tract issues, I don’t think the word “may” should have been used. It implies that “may not” is also true when there is a clear body of evidence, peer reviewed, that would back the statement “will provide health benefit…”

Again, nutrition is not black and white, and we can’t disease-proof ourselves with diet (I certainly wish that we could!). Interactions between our genes, our diet, and the rest of our environment are very complex and very individual. That’s why some people can do “everything right” and succumb to cancer or heart disease at an unfairly early age, while other people can partake heartily of beer, chips and cigarettes and live to a ripe old age. I have patients who are vegan, and each of them is struggling with one or more health issues.

(For more on how different individuals respond differently to diet, see my Washington Post article, “Low-carb vs. low-fat: New research says it really doesn’t matter.”

What good nutrition can do is increase our odds of good health, which I think is a worthy endeavor (if I didn’t, I would be in the wrong profession). While the research supports the benefits of a diet rich in vegetables, fruits, pulses, whole grains and other plant foods, no research states that all people eating this way will see a specific health benefit. That’s why research papers are full of terms like “odds ratios” and “relative risk.”

(For more on what nutrition can—and can’t—do for us, see my Washington Post article, “A healthy lifestyle doesn’t guarantee a long life, but it will add life to your years.”)

I’ve had a many a patient who made profound changes to their diet with the hopes of, say, lowering their cholesterol, only to be frustrated when those numbers don’t budge—but they see other biomarkers change, and maybe they have more energy and are sleeping better. That’s all for the good, but it doesn’t change the fact that dietary changes did not result in the health benefit they were aiming for. So when you suggest changing the words “may provide health benefits” to “will provide health benefits,” that would depend on what benefits you are talking about, and in which individual.

On Saturated Fats…

I just read your piece on “What the Health?” in The Seattle Times and I was excited to see someone finally speak up and call it out for the propaganda that it is. I’m curious on your stance on saturated fats and where you think the fear of saturated fats comes from despite all the new scientific research we now have on the subject. Does it all stem from the pro-vegan PETA folks that just want less harm to animals?

The saturated fats issue is far from settled. Some of the recent research that’s been heralded as “proving” that saturated fats are good for us either a) had flawed scientific methodology or b) actually weren’t saying that sat fats are good for us, they were saying that they aren’t as bad for us as other things we might eat instead (like refined carbohydrates). “Not as bad for us as we thought” ≠ “Good for us.” Generally I think a good question to ask when evaluating whether a food is more healthful or less healthful is: Compared to what?

(For more on that last question, see my Washington Post article, “What to know before trying to improve what you eat.” For more on just how confused we are about saturated fats, see another of my Washington Post articles, “It’s time to get over our fear of dietary fat.”

Also, another exciting evolution in nutrition science (I think) is the movement from looking at the effects of specific food on health, rather than looking at isolated nutrients. So, looking at the effects of butter, or coconut oil, or cheese, or whole milk yogurt, or beef or pork—not just looking at saturated fat. When we eat foods, nutrients don’t exist in isolation, they exist in a complex food matrix made up of a variety of macro and micronutrients.

(For more on saturated fats in dairy, see my article in Today’s Dietitian, “The truth about dairy fats,” and my Seattle Times article, “Why butter isn’t back: Not all saturated fat is created equal.”)

As for whether vegan advocates are the originators of the fear of saturated fat, I think the answer is a complicated one. Certainly, fear of saturated fat from animals has been used to try to convince people not to eat meat, but many vegans partake of coconut oil, and that is full of saturated fat.

(For more on coconut oil, see my Seattle Times article, “Coconut oil: it’s really not that good for you.”)

On Caldwell Esselstyn…

Dr. Esselstyn, Bill Clinton’s doctor at the Cleveland Clinic, seems convinced that if someone wants to avoid heart disease, that a whole foods plant based diet is the only option. After 20 years of research, Is he wrong?

Is he wrong? Yes and no. On the one hand, his 20 years of research did not include randomized controlled trials (i.e., when participants are randomized to different diets to see which diet produces the most favorable outcome), and the patients he put on his very low-fat vegan diet were also placed on cholesterol-lowering drugs. Including drugs in the treatment protocol is a huge confounder, because there is no way to know how much improvement was due to diet and how much was due to the drugs.

Certainly, Dr. Esselstyn had patients who did well on his diet + drug protocol—which is fantastic for them—but the way he did his research makes it impossible to give full credit to the diet (a shame, really). Contrast that with the traditional Mediterranean diet, which is rich in whole plant foods but includes more fat (although not much in the way of animal foods). There is a massive amount of research, including randomized controlled trials, to support that way of eating, which is likely to be easier to stick to than a low-fat vegan diet.

(For more on the Mediterranean diet, see my article in Today’s Dietitian magazine, “Key ingredients of the Mediterranean diet—the delicious sum of nutritious parts.”)

I also take issue with the idea that we can “avoid” any disease. All we can do is reduce our odds of developing disease, like it or not, our genes and our environment also have roles to play. That said, I see nothing wrong with building the best “hand” we can in life, but I think it’s important to balance health with pleasure, because if we don’t enjoy our food, we won’t keep eating that way. Again, I think that’s where the Mediterranean diet comes in.

(For more on what a “plant-based diet” means, see my Washington Post article, “Plant-based diet? Sure, but first understand what that really means.”)

Finally, I had a number of people email me with some variation of “I started eating a vegan diet X years ago and it resolved X health condition and I feel X percent better.” To those individuals, I say, “Awesome! You’ve found a way of eating that works for YOU!” But I’ll add on a few caveats:

Now, please go forth, eat well, and be happy!