It looks like my wish has come true. Last October, I mentioned the need for studies that separate processed meats and unadulterated meats when looking at the effect of meat on our health. There is now such a report. (While I had also wanted these hypothetical studies to compare organic, naturally-raised meats versus factory- farmed meat, I didn’t get my wish, but the research is going in this direction.)
A new meta-analysis review published in the journal Circulation found that while an average of 50 grams of processed meat consumption per day was associated with a 42 percent higher risk of coronary heart disease and a 19 percent increase in type 2 diabetes, 100 grams of unprocessed red meats per day was not associated with these risks. They also noted that unprocessed red meat consumption was not associated with stroke, although this was not a strong association and requires more research.
“When you tease [the data on] these meats out, you see different associations for disease risk between processed and unprocessed meats,” lead researcher Dr Renata Micha from the Harvard School of Public Health, Boston, MA told Heartwire CME.
In the studies, processed meats included meats that are smoked or cured such as hot dogs, deli meats, bacon or sausage while unprocessed red meats included beef, pork or lamb. The study found that unprocessed and processed meats had similar amounts of saturated fat and cholesterol, meaning these macronutrients were not to blame. Where they differed, however, was in the amount of sodium and preservatives found in the processed meat. “This suggests that differences in salt and preservatives, rather than fats, might explain the higher risk of heart disease and diabetes seen with processed meats, but not with unprocessed red meats.”
The preservatives of particular interest are nitrates. These are preservatives added to most processed meats to prevent oxidation, to add flavor and for their anti-microbial properties. Nitrates, along with their close cousin nitrites, have been found to be highly toxic and carcinogenic. Worse yet, they can cause a dangerous condition known as methaemoglobinaemia which is characterized by headache, weakness, increased heart rate and breathlessness. Animal studies have found nitrate preservatives promote atherosclerosis and glucose intolerance, both of which could increase risk of heart disease and diabetes.
Now mind you, this is a meta-analysis and can’t necessarily be taken as gospel. Nonetheless, it certainly gives an indication of the true culprit maligning the safety of meat consumption. It also points to the need for more research and particularly the need to separate processed from unprocessed meats when studying the health effects of eat meat. Given the differences found in this study, it’s important to look at these two types of meat separately when looking at things like cancer, for example, say the authors. Although total meat consumption has been associated with a higher risk of colorectal cancer, unprocessed red meat has not been separately evaluated.
It seems we’re only one step away from getting a study on the effects of naturally raised meat consumption versus that of “conventionally raised.” In fact, I’d be curious to see if naturally smoked or cured meats, free of harmful preservatives, would have the same detrimental effects compared to conventional grocery store fare. I know where I’d put my money.
The Healthy Foodie is Doug DiPasquale, Holistic Nutritionist and trained chef, living in Toronto. Doug specializes in private in-home holistic cooking lessons.