字幕列表 影片播放 列印英文字幕 I'm often asked what my opinion about a diet or disease is. Who cares what my or anyone else's opinion is. All we should care about is what the science says. What does the best available balance of evidence Published in the peer- reviewed medical literature have to say right now? Welcome to the Nutrition Facts Podcast, I'm your host, Dr. Michael Greger. It's time for the Nutrition Facts Grab Bag, where we look at the latest science on a whole variety of topics. And we start today with a story on the micromort. And no, that's not a nickname for your short uncle. Think of it as a unit of comparing and communicating risk to patients. Hundreds of millions of operations are performed every year, and the risk of death is typically around a half a percent, to which patients might say things like, “I could die just as easily crossing the road,” making it clear they really don't understand the difference in magnitude of risk. One way to communicate risk is by analogy. For example, just going under anesthetic carries about a 1 in 100,000 chance you won't wake up. How much is that? Well, that's about the same risk as an expert sky dive. Okay, but that still may be kind of hard to wrap your head around. It's hard to think in terms of small numbers. Imagine discussing a 0.0017 mile x 0.00227 mile rug. How big even is that? We need more digestible units. Enter the micromort as a unit of comparing and communicating risk to patients. A micromort is a unit equivalent to one in a million chance of dying. One in a million is like the chances of flipping a coin and getting 20 heads or tails in a row, or a little less than the chances of getting a royal flush. But the real utility is to help compare different risks to one another, using the same metric. For example, driving a hundred miles entails about a one in a million chance of death, so that's one micromort. Scuba diving is like five micromorts per dive; so, each dive is as risky as driving 500 miles. So, now we have a way to directly compare the risk of surgical procedures and common activities. Giving birth is as risky as driving from NY to LA and then back again, but getting a cesarean is more than twice as risky. Even something like a simple hernia repair carries the same risk of dying as like sky diving 200 times. Now obviously, sometimes you have no choice, but death from varicose vein surgery or circumcision could probably be avoided. I was surprised to learn that regular horseback riding is like four times deadlier than rock climbing, but getting chemo and radiation for head and neck cancer is riskier than rock- climbing for 500 years, driving 5 million miles, or jumping 5,000 sky dives, etc. One leading cause of death I really didn't talk about in How Not to Die is accidental death. We have approximately a one in a million chance of dying just by accident every day of our lives, and about half of that risk is dying in a car crash, based on U.S. averages. Then, there are all sorts of other ways. I am surprised to learn Americans have about a 1 in 200,000 chance every year of dying from a foreign body entering an orifice other than the mouth. Other things we may want to avoid include climbing Mount Everest, about 30 times riskier than coal mining or base jumping. Trains and planes are actually equivalent over the same distance, but riding a motorcycle is about 50 times deadlier than riding in a car, though cycling to a destination is riskier too, about 10 times as deadly as driving in the near term. Here's a good example of how one can use micromort comparisons to help put things in perspective. Certain types of breast implants can cause a rare type of cancer, a type of breast implant- associated lymphoma. You can imagine how scary this is for the millions of women who have implants, but check out the risk compared to the risk of other common activities. Your risk of dying from this kind of cancer is less than a single day of skiing. Now, it's probably better to die quick on the slopes than all the slow suffering of cancer, and risk of bankrupting your family, but at least it can put the risk of the implant-cancer killing you in context. In our next story we ask, do nut eaters live longer simply because they swap in protein from plants in place of animal protein? The American Journal of Clinical Nutrition is the highest ranked peer-reviewed scientific journal in nutrition. That should tell you a lot about the field, since it's published by the American Society of Nutrition, whose sustaining partners include The Sugar Association, candy bar and soda companies, the corn syrup people, and the meat, dairy, and egg industries. And this is the highest ranked nutrition journal. The fact that the National Cattlemen's Beef Association is a sustaining partner may help explain their publication of this article. Imagine you're in the pocket of Big Beef and Big Pig. How could you possibly pull off a study showing that eating red meat does not negatively influence cardiovascular disease risk factors? A meta-analysis of randomized controlled trials showing that eating more versus less red meat does not influence cholesterol or blood pressure. Dr.'s Barnard and Willett pointed out the fatal flaw in their editorial “The Misuse of Meta-analysis in Nutrition Research,” by asking the question “Compared to What?” Of the 39 trials that they had chosen on LDL cholesterol, nearly 90 percent of them were just swapping one meat for another, comparing red meat to white meat. They were using chicken control diets or fish control diets. And we know that when it comes to cholesterol, the impact of beef consumption is just as bad as fish or poultry, and so that's how they pulled it off. They just swapped meats. That's like publishing a study saying total Twinkie intake does not negatively influence risk factors by switching Twinkies with Ding Dongs. Those randomized to zero Twinkies didn't do any better. Yeah, because now they were eating Ding Dongs. It's a classic drug industry trick: testing your drug against something known to be terrible. Whereas if you swap out meat for plant-based meats—plant-based sausages, plant-based chicken patties, and veggie dogs— you end up with significantly lower cholesterol. Well duh, you say, there's less saturated fat in plant-based meats. But even independent of saturated fat content, you end up with higher LDL cholesterol with red meat or white meat— any kind of meat—compared to non-meat protein sources. The researchers conclude that this is keeping with recommendations promoting diets with a high proportion of plant-based food but, based on cholesterol effects, white meat like chicken and turkey is just as bad as red. And fish may be even worse, though what they often did is try to standardize the saturated fat content by adding like butter. But at the same saturated fat content, fish appears to be worse than beef, and chicken is just as bad as beef. Yet plant protein sources like legumes, soy, and nuts– so beans, split peas, chickpeas, lentils, soybeans, and nuts—did better. Switch out a single serving of even lean beef with the same amount of calories of nuts or soybeans, and you can lower LDL bad cholesterol, a key risk factor for the #1 killer of men and women in the United States and around much of the world. But wait, is that why a single serving of nuts a day is associated with 22 percent reduction in the risk of premature death? Why millions of deaths every year may be attributable to inadequate nut intake? Maybe the benefit is just because they're eating nuts instead of meat? No. The drop of heart attacks amongst more frequent nut eaters is just as strong or even stronger among vegetarians. The reduced mortality associated with nut consumption is independent of health condition. It's not just health nuts eating nuts. In fact, in a comparison of a dozen different food groups, nuts beat out even vegetables when it came to a lower risk of premature death. Finally today, we look at the secret to the public health community's triumph when past attempts to regulate the food industry had failed. There are three broad approaches to mediating the ruin of risky choices: inform people (like using labeling), nudge people (for example, by offering financial incentives), or directly intervene to make the activity less harmful. Which do you think prevented more car fatalities: mandating driver education, labeling cars about crash risk, or removing the human element altogether by just making sure air bags are installed? There are public education nutrition campaigns from "sugar pack" ads on public transit, informing consumers how much sugar is in soft drinks, to "Hot Dogs Cause Butt Cancer" billboards, educating about the link between processed meat and colorectal cancer. But is there a way to make products nutritionally safer in the first place? The ban on trans fats offers a useful lesson. In 1993, the Harvard Nurses Study found that high intake of trans fat may increase the risk of heart disease by 50%. That's where the trans fat story started in Denmark, and it ended a decade later with a ban on added trans fats there in 2003. It took another 10 years, though, before the U.S. even started considering a ban. All the while, trans fats were killing an estimated tens of thousands of Americans every year, resulting in as many years of healthy life lost as conditions like meningitis, cervical cancer, and multiple sclerosis. If so many people were suffering and dying, why did it take so long for the U.S. to even suggest taking action? One can look at a fight over New York City's trans fat ban for a microcosm of the national debate. Opposition came down hard from the food industry, complaining about government intrusion, likening the city to a "nanny state." Since trans fats can be naturally found in meat and dairy, the livestock industry echoed the Institute of Shortening's "everything-in-moderation" argument. Critics styled such proposals as the rise of food fascism. But it was the restaurant and food industries that limited consumer choice by so broadly fouling the food supply with these dangerous fats. If food zealots get their wish in banning added trans fats— another argument went— what's next? Vested corporate interests tend to rally around these kinds of slippery slope arguments to try to distract from the very real fact that people are dying. I mean what if the government tries to make us eat broccoli? This actually came up in a Supreme Court case over Obamacare. Chief Justice Roberts suggested Congress could start ordering everyone to buy vegetables, a fear Justice Ginsburg dubbed the broccoli horrible. Technically, Congress could compel the American public to eat more plant-based, Justice Ginsburg wrote, yet one can't offer the hypothetical and unreal possibility of a vegetarian state as a credible argument. As one legal scholar put it, "Judges and lawyers live on the slippery slope of analogies; they're not supposed to ski it to the bottom." New York City finally won its trans fat fight, preserving its status as a public health leader. For example, New York banned lead paint 18 years before federal action was taken, despite decades of unequivocal evidence of its harm. Comparing stroke and heart attack rates before and after the rollout of the trans fat ban in different New York counties, researchers estimate it successfully reduced cardiovascular death rates by about 5%. This then became the model for the nationwide ban years later. How was the public health community able to triumph when attempts in the past to regulate the food industry failed? If you would have asked me about the odds of a national trans fat ban, I would have said, "fat chance." In Denmark, as a leading Danish cardiologist put it, "Instead of warning consumers about trans fats and telling them what they are, we've simply removed them." But we're Americans! As they say here: "You can put poison in the food if you label it properly." If people know the risks, the argument goes, then they should be able to eat whatever they want. But that's assuming they've been given all the facts, which isn't always the case, given the food industry's model of systemic dishonesty, as one health ethics professor put it. Given the predilection for predatory deception and manipulation, government intervention was deemed necessary, but how are you going to get it passed? First, there was a labeling requirement. Manufacturers had to start adding trans fat content to products' nutrition facts labeling. Ostensibly this was to influence consumers, but it may have had a bigger impact on producers. Now that they had to divulge the truth, companies scrambled to reformulate their products to gain a "no trans fat" competitive edge. Within years of the mandatory disclosure, more than 5,000 products were introduced touting low or zero trans fats on their labels. Kentucky Fried Chicken went from being sued for having some of the highest trans fat levels to running an ad campaign where mom tells dad in front of kids that KFC now has zero grams of trans fat, and the father yells, "Yeah, baby! Whoooo!!" and begins eating fried chicken by the bucketful. That was the secret to passing the ban. Once the major food industry players had already reformulated their products and bragged about it, once there wasn't so much money at stake, then there was insufficient political will to block the ban and added trans fats were taken off the playing field. We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to nutritionfacts.org/testimonials. We may share it on our social media to help inspire others. To see any graphs, charts, graphics, images, or studies mentioned here, please go to the Nutrition Facts Podcast landing page. There you'll find all the detailed information you need – plus, links to all of the sources we cite to each of these topics. For a timely text on the pathogens that cause pandemics, order the e-book, audiobook, or hard copy of my last book, “How to Survive a Pandemic”. For recipes, check out my second-to-last book, my “How Not to Diet Cookbook”. It's beautifully designed with more than 100 recipes for delicious and nutritious meals. And all the proceeds I receive from the sales of all my books goes to charity. 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