Does Eating Red Meat Cause Cancer?

Sensationalist headlines about red meat are EVERYWHERE, proclaiming it’s cancerous effects. Is red meat REALLY that bad?

Dead Meat?
There have been many, many correlative studies showing an association between higher meat consumption and higher risk of cancer mortality. Despite these studies being correlative (correlation does NOT equal causation), this is still more than a little concerning, given the sheer volume of studies that have made the meat-cancer association.

Let’s look at a MASSIVE study (131,342 participants) published in 2016 titled: “Association of Animal and Plant Protein Intake With All-Cause and Cause-Specific Mortality”. The study concludes that high animal protein intake is associated with a higher mortality rate AND a higher cancer mortality rate. (1) It’s easy to look at a study like this and concur that eating meat is going to give you cancer.

However, looking deeper, the study reveals that the meat consumption and increased cancer risk pattern ONLY holds up for participants with at least one other factor associated with an unhealthy lifestyle (i.e. obesity, smoking, sedentary lifestyle). Meat consumers WITHOUT any unhealthy lifestyle factors DID NOT have a higher mortality or cancer mortality rate.

(For more on this topic, check out this podcast by Rhonda Patrick, which I pulled heavily from: https://www.acast.com/foundmyfitness/does-meat-consumption-cause-cancer )

IGF-1 and Cancer

IGF-1 and Cancer

Insulin like growth factor 1 or IGF-1 is a hormone that stimulates cell growth. It is a huge part of brain development and bone and muscle growth, especially from conception through adolescence. 

Meat is very protein rich. The amino acids found in proteins directly affect/increase our IGF-1 levels. In extremely simplified terms, the anabolic signals from high circulating levels of IGF-1 promote cell growth, even that of cancer cells. So higher intake of amino acid rich meat leads to higher levels of IGF-1. High levels of IGF-1 may increase cancer risk. This is backed by numerous studies. (2)(10)(11) 

So lowering IGF-1 should drop my mortality risk significantly? 

Not so fast. Although there are potential dangers to excessively high levels of IGF-1, LOW IGF-1 is potentially just as dangerous. Studies show both high AND low levels of IGF-1 increase the risk of all cause mortality. (3) Low IGF-1 is also linked to increased inflammation, cerebrovascular diseases like Alzheimer’s and Dementia, and many other potential negatives. (4)(5)(6) 

IGF-1 is crucial for building muscle, bone health and density, cognitive function, and a host of other important functions. (7)(8)(9)

In short, both low AND high levels of IGF-1 can pose health risks. If you’re concerned about any of the potential health detriments listed above, those in the midrange for IGF-1 levels seem to be at the least risk.

Longevity

So, there doesn’t seem to be a direct link between red meat and cancer. However, excessive amounts of IGF-1 (which can come from too much meat) has been linked to higher cancer risk.

On the other hand, there many negatives to low levels of IGF-1 and under consuming protein.

As with most things, finding a balance seems to be the key. Red meat in moderation has lots of health benefits. And it’s delicious! There are some potential health ramifications to eating TOO MUCH (you probably don’t need it EVERY day), but there are also potential detriments to completely eliminating it. Balance.

Optimal health is never going to feel or look “extreme”.

Being extremely muscular, for example, is going to require lots and lots of IGF-1 boosting amino acids over the years. Someone in a state of optimal health probably isn’t going to look extremely shredded, or overly muscular.

Be aware that taking things to the extremes with your body is POTENTIALLY sacrificing a bit of longevity, and sometimes that’s ok. Weigh out what’s most important to you.

Sources:

(1)  https://www.ncbi.nlm.nih.gov/pubmed/27479196

(2)  https://www.ncbi.nlm.nih.gov/pubmed/15562834

(3)  https://www.ncbi.nlm.nih.gov/pubmed/21795450]

(4)  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2492581/

(5)  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3543345/

(6)  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4013812/

(7)  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1187088/

(8)  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC151128/

(9)  https://www.ncbi.nlm.nih.gov/pubmed/10022403?dopt=Abstract&holding=npg

(10) https://www.ncbi.nlm.nih.gov/pubmed/7619109

(11) https://academic.oup.com/jnci/article/90/12/911/961570