Is red meat bad for you? That's what a new study finds, and it doesn't take much to increase your risk of heart disease by a significant amount. A review of 1.4 million meat-eaters found that regularly digging into a steak or grabbing a burger (or ham sandwich) increases your risk of heart disease by 18 percent.

Why are red meats and processed meats bad for your heart? The study found that three mechanisms are triggered when you eat meat, which can lead to hardening of the arteries, blockages, and possible heart attacks and strokes. The worst meat for you is processed meat, which doubles your odds of getting heart disease.

Heart disease now afflicts 48 percent of the American population, and likely more, since many people may suffer from high blood pressure, a cause of heart disease, without knowing it since it has few symptoms, which is why it's called the "silent killer" according to medical experts. Unprocessed red meat (like beef, pork, and lamb) raises heart disease risk by 9 percent. Plant-based protein has been found to lower the risk of heart disease in previous studies.

Meat-eating has been tied to heart disease in the past

Studies have linked meat-eating with heart disease in the past, but this review is a conclusive look at over a dozen studies and found a definitive connection between meat intake and heart disease. A plant-based diet has been linked to lowering heart disease risk, which is why doctors recommend the Mediterranean diet, or a "green" version of it, cutting out meat and dairy to lower saturated fat intake.

In the new study, moderate consumption of unprocessed red meat was associated with a 9 percent increase in heart disease while processed meat intake is associated with an 18 percent higher risk of heart disease.

Researchers at Oxford’s Nuffield Department of Population Health analyzed data from 13 cohort studies, which in total tracked the health of 1.4 million people for 30 years.

They defined meat as: Beef (including hamburgers), lamb, veal, goat, pork, sausage, ham, bacon, pastrami, deli meat, chicken, nuggets, turkey, and duck among other meats. They defined "meat-eating" as more than 50 grams, or 1.7 ounces, per day. Poultry was not found to have the same dangerous effects on heart disease, the study concluded.

“We know that meat production is a major contributor to greenhouse gas emissions and we need to reduce meat production and consumption to benefit the environment," said Anika Knüppel, a co-lead author of the study.

Why are red meat and processed meat bad for you?

The mechanisms that lead to heart disease among red meat and processed meat eaters is most likely due to three factors:

1. Saturated fat is linked to heart disease.

The saturated fat in meat (and also found in dairy) has been shown to increase LDL cholesterol, a factor in heart disease. LDL causes calcium deposits, or plaque to build up in the arteries, creating blockages, which in turn leads to higher blood pressure and eventually causing heart failure, heart attacks or strokes.

A note about poultry: Unprocessed red and processed meat contain higher amounts of saturated fat per gram than poultry, which could explain the absence of an association with poultry intake, the authors surmise.

2. TMAO causes the hardening of the arteries.

Red meat prompts the body to produce is TMAO, or trimethylamine-N-oxide, which might contribute to an increased risk of heart disease by promoting atherosclerosis, or hardening of the arteries, which also contributes to high blood pressure, heart attacks, and strokes. Meat intake changes the gut microbiome and the bacteria required to break down meat increases circulating TMAO.

3. Processed meat is high in sodium.

Additionally, processed meat has high sodium content, which likely increases the risk of high blood pressure, "a causal risk factor for heart disease." The study concludes: "Red and processed meat consumption is associated with higher levels of inflammatory biomarkers due to their high heme content."

How to reduce risk of heart disease

To reduce the risk of heart disease, replace red meat with plant-based protein such as legumes, vegetables, fruit, nuts, seeds, and whole grains, all of which have plenty of protein. For example, tofu has as much protein as a chicken breast.

There are alternative ways to get all the protein, iron, and B12 you need from whole plant-based foods. On average you need between 46 grams and 56 grams of protein a day (more if you are training for a fitness event).

Most Americans get more protein than their body needs. To calculate how much protein you need, enter your weight into this formula: 0.8 grams of protein per kilogram of body weight, or 0.36 grams per pound. More than that and you may be overdoing it and creating protein overload.

Bottom Line: Does red meat cause heart disease?

This is just the latest study to find that red meat and processed meat are associated with a higher risk of heart disease, and this study found that even 2 ounces a day is enough to raise your risk by up to 18 percent. To cut down on risk, and be heart healthier, ditch the meat and choose plant-based sources of protein instead.

If you’re looking for more ways to incorporate a healthy, plant-based diet into your day-to-day life, check out our Health and Nutrition articles.

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