By Dr. Mercola
At some point, "red meat" became taboo in the nutritional world. If you put good old-fashioned grass-fed, organically-raised meat in a nutrition analyzer, you'd find it's one of the most nutritious foods you can eat.
Still, many people want to believe that all red meat is unhealthy. A new study out of Harvard once again attempts to demonize red meat1.
And despite being profoundly flawed, the study was written up by a number of media outlets, such as The New York Times and CNN Health; their headlines warning that red meat will send you into an early grave.
Among many other problems, the nutrition data for the study was collected via food questionnaires, meaning people had to recall what they'd eaten in the past. Needless to say, this doesn't make for great accuracy. The New York Times reported on the study, stating2:
"People who ate more red meat were less physically active and more likely to smoke and had a higher body mass index, researchers found.
Still, after controlling for those and other variables, they found that each daily increase of three ounces of red meat was associated with a 12 percent greater risk of dying over all, including a 16 percent greater risk of cardiovascular death and a 10 percent greater risk of cancer death.
The increased risks linked to processed meat, like bacon, were even greater: 20 percent over all, 21 percent for cardiovascular disease and 16 percent for cancer. If people in the study had eaten half as much meat, the researchers estimated, deaths in the group would have declined 9.3 percent in men and 7.6 percent in women."
Where's the Science?
Fortunately, many astute health experts have already issued rebuttals to the mass media versions of this shoddy study that has received far more media attention than it could ever possibly deserve. Chris Kressler, L.Ac. sums up the general agreement when he writes3:
"In my fantasy world, researchers don't make the most rookie mistake in the book (claiming that correlation is causation) and science reporters actually have a clue how to critically analyze a scientific study, rather than just parroting what they read on the AP newswire. Alas, reality is not so forthcoming."
In my view, one of the best rebuttals I've seen is by investigative health reporter Gary Taubes. Zoe Harcombe also produced a more in-depth evaluation of the many problems in this study4. In his blog post titled, Science, Pseudoscience, Nutritional Epidemiology, and Meat, Gary Taubes writes5:
"Back in 2007 when I first published Good Calories, Bad Calories I also wrote a cover story in the New York Times Magazine on the problems with observational epidemiology. The article was called "Do We Really Know What Makes Us Healthy?6" and I made the argument that even the better epidemiologists in the world consider this stuff closer to a pseudoscience than a real science.
... The article itself pointed out that every time in the past that these researchers had claimed that an association observed in their observational trials was a causal relationship, and that causal relationship had then been tested in experiment, the experiment had failed to confirm the causal interpretation — i.e., the folks from Harvard got it wrong. Not most times, but every time. No exception. Their batting average circa 2007, at least, was .000. Now it's these very same Harvard researchers — Walter Willett and his colleagues — who have authored this new article claiming that red meat and processed meat consumption is deadly; that eating it regularly raises our risk of dying prematurely and contracting a host of chronic diseases.
... Science is ultimately about establishing cause and effect. It's not about guessing. You come up with a hypothesis — force x causes observation y — and then you do your best to prove that it's wrong. If you can't, you tentatively accept the possibility that your hypothesis was right. Peter Medawar, the Nobel Laureate immunologist, described this proving-it's-wrong step as "the critical or rectifying episode in scientific reasoning."... The problem with observational studies like those run by Willett and his colleagues is that they do none of this. That's why it's so frustrating. The hard part of science is left out and they skip straight to the endpoint, insisting that their interpretation of the association is the correct one and we should all change our diets accordingly." [Emphasis mine]
One of the major problems with using this study to make dietary recommendations or modifications is the fact that the association between disease and eating meat was actually quite small. According to Harcombe, a nutritionist, obesity researcher, and author of The Obesity Epidemic: What caused it? How can we stop it?7:
"The overall risk of dying was not even one person in a hundred over a 28 year study. If the death rate is very small, a possible slightly higher death rate in certain circumstances is still very small. It does not warrant a scare-tactic, 13% greater risk of dying headline – this is 'science' at its worst."
Again, it's imperative to keep in mind that the observation of an association does not mean that one thing actually causes the other. It may, but in order to determine the truth you have to conduct studies to test your hypothesis. Here, we have multiple confounding variables at play; all of which could very well have skewed the results. For example, obesity, a sedentary lifestyle, smoking, alcohol consumption, and higher calorie intake can clearly contribute to an early demise, and as meat consumption went up, so did these confounding factors...
Taubes brings up another excellent point in his article, namely the "compliance" or "adherer effect." This is a confounding factor that is virtually impossible to account for, but it appears to be quite powerful.
In a nutshell, it describes the effect that occurs in groups of people who are simply consistently compliant with a certain recommendation. Interestingly enough, whether it's taking a real medication or taking a placebo, in both cases, those who dutifully take it as prescribed fare better than those who do not. Taubes states that somehow, these people are simply "different," but in what way, exactly, is still unknown. What is apparent, however, is that when you compare "adherers" with "non-adherers" you are comparing two types of people that are essentially incomparable because their mindset and overall dedication to their health is very different.
Most likely, this overall healthier, more dedicated mindset means they're engaging in all sorts of other proactive, preventive behaviors as well that are not include or measured in the study.
According to Taubes:
"No amount of "correcting" for BMI and blood pressure, smoking status, etc. can correct for this compliance effect, which is the product of all these health conscious behaviors that can't be measured, or just haven't been measured. And we know this because they're even present in randomized controlled trials. When the Harvard people insist they can "correct" for this, or that it's not a factor, they're fooling themselves. And we know they're fooling themselves because the experimental trials keep confirming that."
What experimental trials is Taubes referring to? While Willett et.al. may not have done the randomized-controlled trials necessary to investigate the association they claim to have found between premature death and higher meat consumption, such studies have been done by others.
"They're the trials that compare Atkins-like diets to other more conventional weight loss diets," Taubes writes. "These conventional weight loss diets tend to restrict meat consumption to different extents because they restrict fat and/or saturated fat consumption and meat has a lot of fat and saturated fat in it. Ornish's diet is the extreme example.
And when these experiments have been done, the meat-rich, bacon-rich Atkins diet almost invariably comes out ahead, not just in weight loss but also in heart disease and diabetes risk factors... The Stanford A TO Z Study is a good example of these experiments8. Over the course of the experiment — two years in this case — the subjects randomized to the Atkins-like meat- and bacon-heavy diet were healthier. That's what we want to know."
Recent Study Finds Red Meat Associated with Improved Mental Health
Interestingly enough, another recently published Australian study9 concluded that women who avoid red meat appear to be at increased risk of clinical depression. Women consuming less than the recommended amount of red meat were twice as likely to have a diagnosed depressive or anxiety disorder as those consuming less than the recommended amount. Eating very high amounts of red meat was also associated with increased rates of depression.
The researchers suggest a moderate amount of lean red meat—about three to four 6-8 ounce servings per week—may actually be important for mental health. However, they also recommend being careful with the type of meat you choose. As reported by PsychCentral.com10:
"[Felice] Jacka [Ph.D., associate professor from Deakin's Barwon Psychiatric Research Unit] also suggests sticking with grass-fed meats whenever possible. "We know that red meat in Australia is a healthy product as it contains high levels of nutrients, including the omega-3 fatty acids that are important to mental and physical health. This is because cattle and sheep in Australia are largely grass-fed. In many other countries, the cattle are kept in feedlots and fed grains, rather than grass. This results in a much less healthy meat with more saturated fat and fewer healthy fats."
Healthy versus Unhealthy Meats
Many people are still in the dark about the vast differences between concentrated animal feeding operations (CAFOs) and organically-raised, grass-fed beef, both in terms of nutrient content and contamination with veterinary drugs, genetically modified organisms, and disease-causing pathogens. Most CAFO cows are fed grains (oftentimes genetically engineered grains, which make matters even worse), when their natural diet is plain grass. This difference in the animals' diet creates vastly different end products.
Modern mass production of food has created a wide array of safety problems. In fact, once you delve into the world of the food industry, it becomes clear that eating much of it is like playing a game of Russian roulette with your health.
While I'm not going to address them all here, one problem in particular, which relates to the issue of meat, is the issue of contamination with hormones, antibiotics, and pesticides. As much as 70 percent of all antibiotics used in the U.S. are for animals, primarily to serve as growth enhancers. The excessive use of antibiotics in agriculture is the primary reason for the rampant increase in antibiotic-resistant disease in humans. As for pesticides, most people do not realize that conventionally-raised meat is actually one of the primary sources of pesticide exposure—not fruits and vegetables! This due to the fact that CAFO animals are raised on a diet consisting primarily of grains, which are of course sprayed with pesticides.
Decayed Meat Treated with Carbon Monoxide to Make it Look Fresh...
Additionally, many of the methods employed to make food "safer" actually deepen rather than solve them. Take so-called atmospheric packaging, for example. You might not be aware that more than 70 percent of all beef and chicken in the United States, Canada and other countries is treated with poisonous carbon monoxide gas, which can make seriously decayed meat look fresh for weeks!
Although carbon monoxide is a gas that can be fatal when inhaled, the meat industry insists that it is not harmful to human health when ingested via atmospheric packaging, which utilizes carbon monoxide gas to extend the shelf life and resist spoilage. Whatever the truth of that may be, eating spoiled meat is not going to do your health any favors...
According to PreventDisease11 :
"C. perfringens bacteria, the third-most-common cause of food-borne illness, has been proven to grow on what is considered fresh meat ... about half of the fresh meat products [tested for these bacteria] are positive despite them being within the expiry period. One hundred percent of ... these cases come from packagers who adopted atmospheric packaging methods such as the use of carbon monoxide gas".
Why I Only Recommend Eating Organic Grass-Fed Animals
The natural diet for ruminant animals, such as cattle, is grass. When left to feed on grass-only diets, levels of conjugated linoleic acid, or CLA are three to five times more than those fed grain-based diets. And that's just for starters. A joint effort between the USDA and Clemson University researchers in 2009 determined a total of 10 key areas where grass-fed beef is better than grain-fed for human health12. In a side-by-side comparison, they determined that grass-fed beef was:
✓ Lower in total fat
✓ Higher in total omega-3s
✓ Higher in beta-carotene
✓ A healthier ratio of omega-6 to omega-3 fatty acids (1.65 vs 4.84)
✓ Higher in vitamin E (alpha-tocopherol)
✓ Higher in CLA (cis-9 trans-11), a potential cancer fighter
✓ Higher in the B-vitamins thiamin and riboflavin
✓ Higher in vaccenic acid (which can be transformed into CLA)
✓ Higher in the minerals calcium, magnesium, and potassium
✓ Lower in the saturated fats linked with heart disease
Always Avoid Processed Meats
As for processed meat, I am firmly convinced they do increase risk of disease and should NEVER be consumed. That's also the conclusion reached by the World Cancer Research Fund (WCRF) after reviewing more than 7,000 clinical studies examining the connection between diet and cancer.
Processed meats are those preserved by smoking, curing or salting, or the addition of chemical preservatives. This includes bacon, ham, pastrami, salami, pepperoni, hot dogs, some sausages and hamburgers (if they have been preserved with salt or chemical additives) and more. Particularly problematic are the nitrates that are added to these meats as a preservative, coloring and flavoring. The nitrates found in processed meats are frequently converted into nitrosamines, which are clearly associated with an increased risk of certain cancers. The latest research from WCRF is only the most recent of a slew of evidence linking processed meats to cancer.
A 2007 analysis by WCRF found that eating just one sausage a day can significantly raise your risk of bowel cancer. Specifically, 1.8 ounces of processed meat daily -- about one sausage or three pieces of bacon -- raises the likelihood of the cancer by 20 percent. Other studies have also found that processed meats increase your risk of:
- Colon cancer by 50 percent
- Bladder cancer by 59 percent
- Stomach cancer by 38 percent
- Pancreatic cancer by 67 percent
Hot dogs, bacon, salami and other processed meats may also increase your risk of diabetes by 50 percent, and lower your lung function and increase your risk of chronic obstructive pulmonary disease (COPD).