Meat consumption and disease. Is it what we are eating or how we are eating it?
Meat and disease. Two things that are so often grouped together in the media. On the one hand, you have people touting that this is ridiculous, whilst others have embraced a vegetarian diet, never looking back.
So, the question remains, is meat a cause of disease?
Many studies have come out suggesting that meat consumption is associated with an increased risk of certain cancers (such as colorectal cancer) but many of these studies suffer confounding variables. These being vegetarians might have an overall healthier lifestyle, be more active or may drink and smoke less than the average omnivore which may not have been accounted for in the studies. This would result in improved health outcomes for these individuals that may be from factors outside of meat consumption.
Other problems with the conclusions of these studies are that they fail to address dose, frequency and exposure. So, while red meat may be classified as a Class 2 Carcinogen that tells us nothing about its ability to cause disease. Hot beverages, are also considered a Class 2 carcinogen, due to the potential to contribute to oesophageal cancers. Does this mean you should stop drinking your favourite herbal tea? NO!
While we are at it, kale, at a high enough dose, can cause disease.
Finally, another problem with these studies, and one more critical to the point of this article: has the type of meat or the way it has been prepared been accounted for?
There is a big difference between a slow cooked piece of organic, grass fed meat compared to factory farmed processed meat barbequed at high temperatures.
What are the mechanisms?
It has not been entirely pinpointed what the mechanisms behind red meat and disease are, but strong evidence points to the carcinogenic nature of the heterocyclic amines and polycyclic aromatic hydrocarbons, which are formed when meat is ‘well done’ and especially when it is chargrilled or blackened like it is when cooked at high temperatures or on the barbeque.
In saying that, studies have found that these compounds are only carcinogenic after being activated by enzymes produced by certain bacteria in the gut, whereas some probiotics species (for example acidophilus and bifidus sp.) reduce these enzymes, thereby the health of your gut could impact the effect that barbequed meat has on your health. Yet another reason to look after your gut!
Other studies have found the nitrates used as preservatives in processed meat could impact on disease risk.
In one very interesting study, red meat promoted cancer in rodents that were deficient in calcium. However, when calcium was reintroduced, the antioxidant density of the diet was increased or vegetable oils were replaced with olive oil the cancer promoting effect of meat was reversed. This could suggest that the effect that red meat has on disease risk could be associated with other diet factors.
Maybe it’s not the meat, but more the way and the type of meat we are eating.
What can you do to improve your health whilst still enjoying meat?
· Avoid processed meats: Processed meat like bacon, salami, ham, prosciutto (I shed a tear as I type this) should be eaten in moderation. There is nitrate free bacon available so opt for this if you can’t bear the thought of abstaining!
· Limit your intake of chargrilled or BBQ meat. When you cook any meat, ideally it will be at a lower temperature to avoid the formation of potentially carcinogenic compounds. Aim to make most of the meat you consume slow cooked in the oven or in a slow cooker. If you do consume BBQ meat include plenty of greens, as the phytochemicals can help to reduce the risk. As if you needed any more reason to up your intake of greens!
· Improve your gut health. As above some studies have suggested that the type of bacteria in your gut can have an impact on the effect of potentially carcinogenic compounds. While this research is in rodents so must be taken with a grain of salt, it can never hurt to work on improving gut health!
Always opt for grass-fed/ free-range and ideally organic where possible. Unfortunately, this does come with an added price tag, so perhaps it can be beneficial to lower your overall intake of meat in the diet & opt for quality over quantity.
There are immense benefits to eating meat. It is an easily digested protein source and has high bioavailability of a lot of essential nutrients. Meat is also an excellent source of vitamin B12 which is not possible to get from a natural, common, plant-based diet alone (supplementation is necessary in vegans). In saying that though, most of us are probably eating too much of it in place of other nutritious foods such as vegetables. So, the take home message is to eat a plant-based diet, supplemented with some meat if you choose, but to be mindful of the types of meat or way that it is prepared.