The Truth About Red Meat

Ok, I’ll come clean, any article that claims to reveal the “absolute truth” about anything on the topic of nutrition will be one of two things: 1) Extremely naive, full of bias and probably wrong; and 2) Using a punchy and controversial headline to grab your attention

This article is guilty of the latter.

Whilst I may be a tiny bit ashamed of using such deceptive techniques I am hopeful that you were not fooled by such an overstated title and it does serve to highlight, quite nicely, the amount of unwarranted certainty, and deception, that is pedalled to an unsuspecting general public in the form of nutritional science, perhaps never more so than on the topic of red meat and whether you will die horribly if you eat it.

I love red meat, there I said it, I’m declaring my potential bias right off the bat. I also love white meat, fish, vegetables, fruit and nuts but I’m not keen on eggs, celery, milk or pasta. You now know pretty much everything there is to know about my nutritional biases. I would also like to state that it doesn’t matter to me whether you’re a meat lover, a paleo, a vegetarian, vegan, pescetarian (eats fish, but not meat) or if you just eat whatever is on your plate at the time. Your life. Your food. Your health. You do what you want. I’m not here to preach, goodness knows there is enough of that out there already. What I am here to do is clear up some of the confusion and deception, often accidental, occasionally deliberate, regarding what science really tells us about the healthfulness of red meat.

Bad Evidence

Since the 1970’s and the advent of the Diet-Heart hypothesis, red meat has stood in the dock, accused of the most heinous crimes against health, largely based on two suppositions. Firstly, the notion that red meat causes cancer and chronic illness and, secondly, the notion that the saturated fat in red meat will raise cholesterol and cause heart disease. Not a day goes by, it seems, that we aren’t slapped across the face with a big juicy Daily Mail news story about how the latest scientific study has conclusively proven that if you eat red meat you will undoubtedly die horribly from bowel cancer before you are forty, unless a gruesome heart attack kills you first. Are all these studies wrong? Well, as is so often the case, it’s not quite that simple. The problem is that most of the studies condemning red meat as a maniacal serial killer are epidemiological studies, based on observation, with data collected through free living food diaries and questionnaires, rather than being accurately recorded under clinical conditions. 

When it comes to making statements about the healthfulness of red meat and what can be concluded for certain under these study conditions, we are faced with several serious issues. Firstly, the inaccuracies of food diary data are well known and extremely well documented, which makes it very difficult to ever determine just how much of a danger component red meat represents because we can never be sure exactly how much is actually being consumed.

Secondly, observational data is often corrupted by something known as “healthy user bias”. When certain foods or lifestyle habits are outlawed by mainstream health, healthy people tend to steer away from them. So, for example, people who tend to avoid red meat because of its “unhealthy” label, also tend to exercise more, smoke less, drink less alcohol, eat more greens and indulge in generally healthy lifestyle habits, whilst those who choose to ignore the red meat warnings tend to have less interest in exercise, are more likely to smoke and drink, rarely get their five a day and commonly indulge in less healthy habits. Under these circumstances it’s easy to see how red meat may have found itself in the firing line along with other known sources of ill health.

Finally, and most importantly, observational studies can never prove causality. They can provide some insights into what may be the cause of an illness or condition and they can certainly help point us in the right direction but you cannot discern a definite cause. Think about it for a moment, if we were to rely purely on observation to determine cause we might find ourselves arresting firemen on suspicion of arson because commonly when we see a raging fire we also see firemen, so it’s likely that firemen are actually starting the fires, isn’t it? At the site of car crashes we commonly see skid marks on the road, so perhaps skid marks are to blame and we should spray tarmac with non-stick teflon, shouldn’t we? Ok these might seem like silly examples but they are only silly because we know for certain that they do not represent causality. And therein lies the problem with observational studies, until we can prove causality, nothing should be inferred or assumed to be true. 

Good Evidence

Hopefully you can now see why we should be wary whenever we are presented with shock science stories, often misrepresented or delivered without context, that might deter us from eating red meat. However, to keep this article free from self-indulgent opinion, let’s take a look at what the best science actually says regarding red meat consumption and its prevalence for causing chronic illness such as cancer and heart disease. The very best scientific evidence comes in the form of meta analysis and clinical reviews. These are studies which effectively look at all the studies conducted to date on a particular topic, in this case “does red meat cause cancer?” (The most common cancer linked with red meat consumption is colorectal or bowel cancer) They throw out the studies which were poorly conducted, evaluate the ones that had critical value, put all of the available data together and crunch the numbers to determine, from a much larger pool of data, what the evidence tells us about the question at hand. So what do the meta analysis and study reviews tell us about red meat? Well, two such meta analysis published in 2011 both found the evidence was insufficient to support a positive association between red meat consumption and colorectal cancer.

What about all the saturated fat that will lead to cholesterol clogging up our arteries, surely everyone knows that’s true? Well, once again, it’s just not that simple. Despite popular belief, there is no conclusive evidence demonstrating that saturated fat in red meat elevates cholesterol levels, or even that elevated cholesterol levels are harmful. One large cohort study comprised of almost 350,000 participants found no association between saturated fat consumption and coronary heart disease or cardiovascular disease. In another study conducted in Japan, 60,000 women found an inverse relationship between saturated fat consumption and incidents of stroke, the more saturated fat they ate the lower their chance of having a stroke. In fact, the scientific literature is riddled with studies which seem to go completely against the idea that only bad things can come from eating red meat and saturated fat or having high levels of cholesterol. 

The Benefits Of Red Meat

But let’s move away from all the death and illness for a moment, what are the health benefits of red meat? Well, it’s a long list so let’s just take look at the big ones. Red meat is one of the richest sources of vitamin B12 as well as most of the other B vitamins. In particular, B12 plays a vital role in everything from neurological and mental health to cardio vascular health, cancer prevention and fertility. Red meat also contributes towards vitamin D intake. Whilst not as good as sun exposure or oily fish, red meats contain a vitamin D metabolite called 25-hydroxycholecalciferol which can be utilised by the body far more readily than other dietary forms of vitamin D. In addition, red meat has been shown to protect against degenerative bone disorders, such as rickets, more effectively than milk containing the same level of vitamin D, which would indicate that vitamin D from meat is in someway more absorbable.

If you are looking to optimise intake of important minerals such as iron and zinc, it really is hard to beat red meat. Zinc, vital for constructing proteins and enzymes, proper brain function and even gene expression, is found in highly bioavailable form in red meats and even helps in the absorption of zinc from other sources such as the less commonly consumed offal meats and shellfish. Research has also shown that non-meat eaters tend to be at a higher risk of zinc deficiency. Iron is another mineral found in abundance in red meat. Especially important for women looking to become pregnant as it helps to develop the foetal brain, the iron found in red meat is primarily heme iron which is utilised far more effectively than the non heme iron found in plants and even aids the absorption of non heme iron and iron from other sources. 

If we throw in a bunch of other important minerals; magnesium, phosphorus, chromium, selenium, copper, we have a veritable feast of healthy goodness when we consume red meat. Yes, it is true that white meats contain similar levels of vitamins and minerals, however, there are several areas in which white meats simply cannot compete, namely vitamin B12, zinc, iron and, perhaps most importantly, good fats. The fatty acid profile found in red meat is high in saturated fats and monounsaturated fats (the good stuff) but low in polyunsaturated fats (the bad stuff) and is also far less susceptible to change as a result of the animal’s feed. 

Conclusion

So, to conclude, what should we make of all this science and how should it affect our choices when it comes to consuming red meat?

Do these studies and meta reviews strongly suggest that red meat may have been wrongly accused and sentenced for a crime it did not commit? Yup. 

Do they prove conclusively that red meat is definitely not harmful? Nope. 

Have we been subjected to decades of unwarranted and unnecessary scaremongering by people who are either trying to sell newspapers, have a vested interest or belief, or have simply misunderstood the science? Oh yes.

Should we avoid white meats, fish and other protein sources and simply eat burgers and steak every day? Certainly not.

Are you going to die of horrible illnesses as a direct result of enjoying your Sunday roast? Highly unlikely. 

Just like vegetables, fruits, fish, white meats, nuts, pulses and other nutritious foods, for most of us red meat has a vital role to play in optimum health. Of course, you ideally want to choose grass-fed sources, get the best quality possible and avoid charring or burning it but if you like to eat red meat and feel energised when you do, don’t deprive yourself of an incredibly nutritious food source based on the scaremongering and naivety of misinformed journalists pedalling their shock “science” stories, because, right now, it seems science is sat at the table right beside you and it’s tucking into a big juicy steak.

References

1. Yanetz R, Kipnis V, Carroll RJ, et al. Using biomarker data to adjust estimates of the distribution of usual intakes for misreporting: application to energy intake in the US population. J Am Diet Assoc. 2008;108(3):455–64– discussion 464. doi:10.1016/j.jada.2007.12.004.
2. ‍ Millen AE, Tooze JA, Subar AF, Kahle LL, Schatzkin A, Krebs-Smith SM. Differences between food group reports of low-energy reporters and non-low-energy reporters on a food frequency questionnaire. J Am Diet Assoc. 2009;109(7):1194–1203. doi:10.1016/j.jada.2009.04.004.
3. ‍ Tooze JA, Vitolins MZ, Smith SL, et al. High levels of low energy reporting on 24-hour recalls and three questionnaires in an elderly low-socioeconomic status population. J Nutr. 2007;137(5):1286–1293. Available at: http://jn.nutrition.org/content/137/5/1286.long.
4. ‍ Lichtman SW, Pisarska K, Berman ER, et al. Discrepancy between self-reported and actual caloric intake and exercise in obese subjects. N Engl J Med. 1992;327(27):1893–1898. doi:10.1056/NEJM199212313272701.
5. ‍ Price GM, Paul AA, Cole TJ, Wadsworth ME. Characteristics of the low-energy reporters in a longitudinal national dietary survey. Br J Nutr. 1997;77(6):833–851.
6. Meta-analysis of prospective studies of red meat consumption and colorectal cancer. Alexander DD1, Weed DL, Cushing CA, Lowe KA. Eur J Cancer Prev. 2011 Jul;20(4):293-307. doi: 10.1097/CEJ.0b013e328345f985.
7.  Red meat and colorectal cancer: a critical summary of prospective epidemiologic studies. Alexander DD1, Cushing CA. Obes Rev. 2011 May;12(5):e472-93. doi: 10.1111/j.1467-789X.2010.00785.x.
8. ‍ Does Dietary Saturated Fat Increase Blood Cholesterol? An Informal Review of Observational Studies   http://wholehealthsource.blogspot.co.uk/2011/01/does-dietary-saturated-fat-increase.html
9.  Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Siri-Tarino PW1, Sun Q, Hu FB, Krauss RM. Am J Clin Nutr. 2010 Mar;91(3):535-46. doi: 10.3945/ajcn.2009.27725. Epub 2010 Jan 13.
10.  The JPHC study: design and some findings on the typical Japanese diet. Tsugane S1, Sawada N2. Jpn J Clin Oncol. 2014 Sep;44(9):777-82. doi: 10.1093/jjco/hyu096. Epub 2014 Aug 7.
11.  http://onlinelibrary.wiley.com/doi/10.1111/j.1467-3010.2010.01871.x/abstract
12. ‍ http://journals.cambridge.org/action/displayAbstract fromPage=online&aid=790996&fileId=S0029665197000530
13. ‍ http://onlinelibrary.wiley.com/doi/10.1111/j.1467-3010.2010.01871.x/abstract
14. ‍ Bioavailability of iron, zinc, and other trace minerals from vegetarian diets1,2,3,4. Janet R Hunt. The American Journal of Clinical Nutrition 2011
15. ‍ http://onlinelibrary.wiley.com/doi/10.1111/j.1467-3010.2010.01871.x/abstract
16. ‍http://onlinelibrary.wiley.com/doi/10.1111/j.1467-3010.2010.01871.x/abstract