Published July 27 2015
Many natural healthcare professionals recommend an autoimmune paleo diet to their patients. This diet is a variation of the “standard” paleo diet, as the main foods consumed are vegetables, fruits, meat, poultry, and fish. But some people become concerned about eating a few servings of meat on a daily basis, especially red meat, and so I figured I’d write an article to address this concern.
Before I continue, I do want to let you know that I commonly recommend an autoimmune paleo diet to my patients, although I might make some modifications depending on the patient. However, I also work with some vegetarians and vegans, and so while I personally eat meat and poultry, I never try to convince any vegetarians to eat these foods. One can bring up the ethical issues of eating animals, and can also argue that it is healthier to be a vegetarian, etc. I’m not going to discuss this here, as the main focus of this article is to determine whether eating red meat is harmful for those people with thyroid and autoimmune thyroid conditions.
Why Is There A Bad Rap On Red Meat?
As you know, there are two sides to every story. There are healthcare professionals who warn people about the dangers of eating red meat, and there are also highly regarded healthcare professionals who encourage their patients to eat red meat. I always try to keep an open mind, and so even though I eat red meat and I’m fine with my patients eating red meat, I realize that there are some risks with eating red meat, which I’ll of course discuss in this article.
Perhaps the best place to start is by looking at some of the evidence which shows some of the potential risks of eating red meat.
Red meat and inflammation. In the past this is one of the main arguments I made against eating red meat on a frequent basis. I specifically spoke about arachidonic acid, which is involved in the inflammatory process. Arachidonic acid is an essential fatty acid and is formed from the synthesis of linoleic acid, and is a precursor in the biosynthesis of prostaglandins, thromboxanes, and leukotrienes (1). Some arachidonic acid is normal, but higher amounts can be problematic, and high levels of this is common in people who eat large amounts of omega 6 fatty acids and lower amounts of omega 3 fatty acids. Most conventional red meat has higher levels of omega 6 fatty acids, and thus arachidonic acid can be an issue.
Based on this information it might make sense for those who have inflammatory conditions such as Graves’ Disease and Hashimoto’s Thyroiditis to avoid red meat. And in the past I did in fact tell my patients to minimize their consumption of red meat due to the risks of inflammation associated with arachidonic acid. However, what’s important to understand is that not all red meat is created equal. Many people reading this are aware of the differences between grass-fed beef and grain-fed beef. Studies clearly show that grass-fed beef has a greater amount of omega 3 fatty acids and a decreased amount of omega 6 fatty acids when compared to grain fed beef (2) (3) (4) (5). However, it’s important to make sure the cow was 100% grass fed, as many are fed grass but for the last few weeks of their lives are fed grains, which will affect the fatty acid ratio. So when you purchase red meat you want to make sure it says 100% grass fed.
Red Meat and Neu5Gc. Neu5Gc is a compound found in beef, as well as pork, lamb, and dairy products (6). Some researchers have expressed a concern that we produce antibodies against Neu5Gc, and this can cause inflammation and other health conditions in those who eat red meat (7). And so when we eat red meat, Neu5Gc might become incorporated into human tissues. And if someone has anti-Neu5Gc antibodies then this can cause inflammation, which of course isn’t a good thing. The problem is that the evidence is far from being conclusive, and people have been eating red meat for a very long time without developing all of the chronic health conditions we see today. And so even if some people do have anti-Neu5Gc antibodies, can we conclude that these develop due to eating all types of red meat? At this point more research is definitely needed in this area.
One study I came across did show increased anti-Neu5Gc antibodies in patients with hypothyroidism and Hashimoto’s Thyroiditis (8). The authors concluded that the correlation of anti-TPO antibodies with increased anti-Neu5Gc antibodies means that there might be an association between anti-Neu5Gc antibodies and autoimmune hypothyroidism (8). So does this mean that the consumption of animal products can cause Hashimoto’s Thyroiditis due to the development of anti-Neu5Gc antibodies? Perhaps, but just keep in mind that the incidence of Hashimoto’s has skyrocketed over the last few decades, yet humans have been consuming animal products for a very long time. By the way, the same study showed that rheumatoid arthritis does not involve elevated anti-Neu5Gc antibodies, which means that these antibodies aren’t involved in all autoimmune conditions.
Red Meat and TMAO. Trimethylamine N-oxide (TMAO) is a chemical which can lead to cardiovascular disease. Studies show that L-carnitine, which is present in red meat, produces TMAO and accelerates atherosclerosis in mice (9). The same studies also showed that humans who were omnivores produced more TMAO than did vegans or vegetarians, and so the natural conclusion is that eating red meat increases the risk of heart disease.
Although there was always some concern about red meat increasing the risk of heart disease, this study seemed to prove that this was the case. However, it also doesn’t take into account the type of meat, as without question there is a big difference between processed meats and unprocessed meats. In addition, there is also a difference between “standard” unprocessed meats and 100% organic grass fed beef. It would be interesting to compare the levels of TMAO of those whose diet consisted mostly of fast food burgers and those who ate mostly organic grass fed beef. Perhaps the levels of TMAO would be similar, and if this were the case then perhaps we can conclude that eating red meat, regardless of the source, can increase the risk of cardiovascular disease.
Chris Kresser has written numerous articles on red meat, and in an article he wrote about TMAO he explained how the problem is most likely not related to the red meat, but the unhealthy gut flora in those who eat red meat. Looking back at the study I mentioned earlier, it discusses how the intestinal microbiota is what ultimately produces TMAO through the metabolism of L-carnitine. In his article, Chris discusses how people who eat red meat on average engage in unhealthy eating behaviors which causes intestinal dysbiosis, thus leading to the increased production of TMAO. In other words, people who eat conventional red meat are likely to eat other unhealthy foods, perhaps not exercise regularly, etc. Without question more research needs to be done in this area, as they need to factor in not only the quality of the red meat being consumed, but other potential lifestyle factors that can play a role.
Red meat and cancer. Ever since I was young I loved eating beef burgers. But the problem with grilled burgers is that it leads to the production of compounds which can be harmful to our health. This includes advanced glycation end products (AGEs), heterocyclic amines (HAs), and polycyclic aromatic hydrocarbons (PAHs). These compounds are increased with certain foods such as red meat, and the cooking procedure also plays a big role in their formation, regardless of the type of meat. Animal-derived foods that are high in fat and protein generally have higher amounts of AGEs, whereas carbohydrate-rich foods such as vegetables, fruits, whole grains, and milk contain relatively few AGEs, even after cooking (10). AGE formation is significantly reduced by cooking with moist heat, using shorter cooking times, cooking at lower temperatures, and by use of acidic ingredients such as lemon juice or vinegar (10). And so for example, if you like to grill your burgers, one of the things you can do to reduce the formation of AGEs is to marinade the meat in lemon juice for approximately one hour before grilling the burgers. In addition, L-carnosine has been shown to inhibit AGE formation (11) (12), and so taking an L-carnosine supplement right before eating a grilled burger might help to minimize any adverse effects.
For those who aren’t willing to take the proper precautions, there very well might be an increased risk of cancer. For example, one study showed that well-done, grilled red meat increases the risk of colorectal adenomas , which once again is due to the carcinogenic compounds formed by the high-temperature cooking techniques (13). Another study showed that eating well-done red meat increases the risk of prostate cancer (14). The same study showed that white meat consumption was not associated with prostate cancer. However, a comprehensive review showed that the associations between red meat consumption and colorectal cancer are general weak in magnitude, and that the evidence is not sufficient to support a positive association between red meat consumption and colorectal cancer (15).
I recently attended a detoxification and biotransformation conference from the Institute for Functional Medicine, and they briefly spoke about the risk of eating well done burgers. However, one of the presenters made a good point about how the accompanying food choices one makes when eating a grilled burger can also play a role. For example, they mentioned how if someone were to eat a cup of lightly steamed broccoli with the burger that the antioxidants from the broccoli can help to neutralize the free radical effects caused by the AGEs. So besides marinating the burger before grilling it and taking an L-carnosine supplement prior to eating it, eating some broccoli with it and other anti-oxidant rich foods may help to neutralize any negative effects.
Is White Meat A Better Option?
In the past I encouraged my patients to eat more poultry and less beef. However, one can make the argument that eating 100% grass fed beef is healthier than eating leaner meats such as poultry. And one of the main reasons is because chicken and turkeys are commonly fed grains. This is true with most organic poultry as well, unless if it is pasture raised. Does this mean those people with thyroid and autoimmune thyroid conditions should eat 100% grass-fed beef on a regular basis? Well, obviously one doesn’t have to eat grass-fed beef in order to receive good results when following a natural treatment protocol. But for those who do eat meat, grass-fed beef is nutrient dense, as it’s a great source of vitamin B12, niacin, vitamin B6, iron, zinc, phosphorus, potassium and other nutrients (16) (17). Plus, there isn’t any sound evidence that 100% grass fed beef is harmful to eat on a regular basis, assuming it is cooked appropriately and/or certain precautions are taken when using cooking techniques such as grilling.
Sure, there are many studies showing that there are health risks associated with eating red meat. Many of them are associated with red meat causing cardiovascular disease or cancer. And a recent study showed that eating red meat increases the risk of developing type 2 diabetes (18). This study involved 442,101 participants and 28,228 people with diabetes, and it showed that the consumption of both unprocessed and processed red meat was significantly associated with an increased risk of type 2 diabetes. Processed red meat included bacon, hot dogs, sausage, etc. But the problem is that the “unprocessed meat” doesn’t necessarily mean 100% grass fed beef, but most likely consisted of grain fed beef in cows treated with growth hormones. Even so, the risk of developing type 2 diabetes when eating the processed red meat was much higher than eating unprocessed red meat.
What we really need are some similar studies involving 100% grass fed beef. Because let’s face it, cows weren’t meant to eat grains, and of course these days most cows are fed genetically modified corn. It would be interesting to see a study comparing the overall health of humans who only ate 100% grass fed beef for a certain period of time, and those who only ate conventional meat. Plus, as I mentioned already, one also needs to consider that people who eat a lot of lower quality meat are more inclined to eat unhealthy foods when compared to those who make an effort to eat grass fed beef. This is especially true for those who eat beef burgers from fast food restaurants, as many of these people are also eating greasy fries and drinking soda, along with other unhealthy foods. And so even if a study were done comparing the health risks of 100% grass fed beef with conventional beef, it is possible that other factors could be responsible for the increased incidence of cardiovascular disease, and not just the red meat. However, in all likelihood those people who eat 100% organic grass fed beef also eat healthier foods than those who eat conventional red meat.
What’s The Final Verdict?
So even with the information I provided you still might question whether or not it’s safe to eat red meat, even if it’s 100% grass fed beef. After all, while I have argued that most studies involving the risks of red meat use non organic grain fed beef, at the same time there aren’t any long term studies which shows that eating 100% grass fed beef is safe. However, we do know that the incidence of cardiovascular disease has skyrocketed over the years, and so there are a few things we CAN conclude. First of all, we can conclude that many years ago cows weren’t fed GMO corn, and also weren’t pumped with growth hormones or given antibiotics. Second, we can conclude that in the past there weren’t as many processed foods people were eating, and many people who currently eat red meat from cows that were fed GMO corn and were given hormones frequently eat other unhealthy foods as well.
Before I conclude this article, I want to share one important study I came across which discussed how scientific evidence is accumulating that meat itself is not a risk for Western lifestyle diseases such as cardiovascular disease, but instead the risk comes from the excessive fat associated with the meat of modern domesticated animals (19). It was mentioned how their studies showed evidence that diets high in lean meat can lower plasma cholesterol, contribute significantly to tissue omega-3 fatty acid and provide a good source of iron, zinc, and vitamin B12 (19). So this is yet something else to consider, as besides the fact that cows of the past weren’t fed GMO corn and weren’t given growth hormones or antibiotics, in the past the meat was wild game, and didn’t consist of cows in factory farms. Most cows between the ages of six months and one year spend all of their time in feedlots with hundreds, or even thousands of other cows, without pasture, standing in their own waste, and are fed an unhealthy diet consisting primarily of GMO corn. In most cases it is this type of meat that has been used in all of these studies.
In summary, if red meat alone causes an increase in cardiovascular disease, cancer, and other health conditions, one would have expected our ancestors who ate red meat to also have developed these diseases. However, there is no evidence that our ancestors who ate red meat on a frequent basis had an increased risk of these chronic health conditions. This further provides evidence that red meat itself isn’t necessarily the culprit, but instead it is the quality of the red meat, along with other unhealthy lifestyle habits of people who commonly eat conventional red meat. However, certain cooking techniques such as grilling can increase the risk of developing certain health conditions, even in those people who eat 100% grass fed beef. Keep in mind that the cooking techniques not only affect red meat, but other types of meat as well.