A saleswoman takes meatloaf from a meat counter in a supermarket. Photo: Jan ... [+] Woitas/dpa-Zentralbild/ZB (Photo by Jan Woitas/picture alliance via Getty Images)

The notion that processed meat is not good for your health is not a new one. The high salt content, additives, and even just the red meat itself are all known to be linked to increased incidence of high blood pressure, heart disease, and obesity. But it is also known that studies assessing nutritional intake and health outcomes are notoriously difficult to carry out, and even more difficult to interpret. Even when such studies attempt to tease out other lifestyle variables such as exercise habits, tobacco use, alcohol intake, stress, and sleep quality, the data are always subject to debate, especially when a smattering of genetics and co-morbidities (other health issues) are thrown in.

A 2019 editorial in the Annals of Internal Medicine pointed out the reasons for these inconsistencies. In it, the authors describe several studies with vastly differing conclusions, ranging from processed meat is carcinogenic to processed meat is probably carcinogenic to the association between processed meat consumption and colon cancer and cardiovascular disease is weak. The editorial then reviews several meta-analyses which included hundreds of other studies, totaling over six million individuals. These studies found extremely small differences in overall health outcomes based on processed meat consumption, including all-cause mortality, cancer, and heart disease.

Three year old child eating salami

Because even the largest nutritional studies are observational, with so much of the data subject to confounding variables of other lifestyle habits and genetics, even those with high statistical significance for any link between sausage links and heart disease are not necessarily translatable in the real world of objective data. Better studies look at randomized controlled trials, which, even if performed over shorter duration, as short as six months as opposed to many years, may offer more accurate results than purely observational data. But even these studies have not determined with any certainty the health benefits or harms of meat consumption.

A more recent study, published in the February 3, 2020 issue of JAMA Internal Medicine, included not only processed meat consumption as a potential association with cardiovascular disease and death, but also unprocessed red meat, poultry, and fish consumption. But again, even this study looks at association, which is quite different from causation. As an analogy of association, a sunny day is associated with crowds at the beach, but the sunny skies did not cause the beach to be crowded. Association has been muddied into causation in countless debates on health data, including data on meat consumption, red wine consumption, vaccination schedules, and screen time, to name just a few. The authors of this months JAMA study sought to find an association (again, not causation) between various types of meats and fish with all-cause mortality and cardiovascular disease.

Young Woman Eating Chicken

The study collected data between 1985 and 2002, and participants were followed until 2016. The subjects included over 29,000 adults from six individual cohort studies. The average age was 53 years, and included roughly equal numbers of individuals who identified as male or female. Seventy percent of the subjects were white. Of the four types of consumed products, those with any of the three types of meat consumption, including poultry, had increased incidence of cardiovascular disease compared to those reporting only fish consumption. Both processed and unprocessed meat consumption were associated with increased all-cause mortality compared to those consuming just fish or poultry. All good news for you fish and fowl consumers? Perhaps. But even this study is one of association, despite the fact that they followed subjects for many years, in whats known as a prospective as opposed to a retrospective study.

In a prior Forbes article, I reported on clinical guidelines published in the October 2019 issues of the Annals of Internal Medicine, which found that there were no health benefits to reducing processed or unprocessed meat consumption. Digging a little into that study authors relationships quickly found that they had financial ties to the meat industry. Clearly an association that will bias any data, even when the data showed association, not causation.

Coming into play now is the health of our planet, not just our coronary arteries. Many environmental studies are pointing at meat (and dairy) consumption as major sources of greenhouse gases, and that if we humans all became vegetarians (or better, vegans), the impact on reducing climate change and improving air quality would save us all. Other data have found this not to be the case, showing that animal agriculture accounts for less than 4% of U.S. greenhouse gas emissions. Another way of looking at meat consumption data is by the energy needed to produce the energy meat gives. In other words, one study reported that livestock use 80% of farmland energy but produce only 18% of consumed calories. In addition, beef produce over 100 kilograms of greenhouse gases per 100 grams of protein they provide, whereas tofu, a plant-based soy protein, produces only 3.5 kilograms of greenhouse gas for that same 100 grams of protein.

Beef cattle standing in a field

We still do not have answers when it comes to meat consumption- neither for our own health nor for the health of our planet. While many human studies are leaning towards data showing poorer health outcomes with meat consumption, and environmental studies are also showing negative impacts on the climate due to beef agriculture, definitive data is still up for grabs. No matter how you slice it.

The rest is here:
The Heartbreak Of The Deli Counter: More Thinly Sliced Data - Forbes

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