Slicing off the facts from the fiction: know about the role meat plays in your health

Dariush Mozaffarian

It’s no wonder you’re confused. One group of scientists says that reducing red and processed meat is a top priority for your health and the planet’s. Another says these foods pose no problems for health. Some of your friends may say it depends, and that grass-fed beef and “nitrite-free” processed meats are fine. At the same time, plant-based meat alternatives are surging in popularity, but with uncertain health effects.

As a cardiologist and professor of nutrition, I’d like to clear up some of the confusion with five myths and five facts about meat.

First, the myths. Myth: Red meat is good for health
Long-term observational studies of heart disease, cancers or death and controlled trials of risk factors like blood cholesterol, glucose and inflammation suggest that modest intake of unprocessed red meat is relatively neutral for health. But, no major studies suggest that eating it provides benefits. So, while an occasional serving of steak or lamb may not worsen your health, it also won’t improve it. And, too much heme iron, which gives red meat its color, may explain why red meat increases risk of Type 2 diabetes. Eating red meat often, and eating processed meat even occasionally, is also strongly linked to colorectal cancer.

Myth: You should prioritise lean meats
For decades, dietary guidance has focused on lean meats because of their lower fat, saturated fat and cholesterol contents. But these nutrients don’t have strong associations with heart attacks, cancers or other major health outcomes.
Other factors appear more important. Processed meats, such as bacon, sausage, salami and cold cuts, contain high levels of preservatives. Sodium, for example, raises blood pressure and stroke risk, while the body converts nitrites to cancer-causing nitrosamines. Lean or not, these products aren’t healthy.

Myth: Focus on a ‘plantbased’ diet
“Plant-based” has quickly, but somewhat misleadingly, become a shorthand for “healthy.” First, not all animal-based foods are bad. Poultry and eggs appear relatively neutral. Dairy may have metabolic benefits, especially for reducing body fat and Type 2 diabetes. And, seafood is linked to several health benefits.
Conversely, many of the worst foods are plantbased. Consider white rice, white bread, fries, refined breakfast cereals, cookies and so on. These foods are high in refined starch and sugar, representing 42% of all calories in the U.S., compared to about 5% of U.S. calories from unprocessed red meats, and 3% from processed meats. Either a “plant-based” or omnivore diet is not healthy by default. It depends on what you choose to eat.

Myth: Grass-fed beef is better for your health
Conventional livestock eat a combination of forage (grass, other greens, legumes) plus hay with added corn, soy, barley or grain. “Grass-fed,” or “pastureraised,” livestock eat primarily, but not exclusively, forage. “Grass-finished” livestock should, in theory, only eat forage. But no agency regulates industry’s use of these terms. And “free range” describes where an animal lives, not what it eats.
“Grass-fed” may sound better, but no studies have compared health effects of eating grass-fed versus conventional beef. Nutrient analyses show very modest differences between grass-fed and conventionally raised livestock. You might eat grass-fed beef for personal, environmental or philosophical reasons. But don’t expect health benefits.

Myth: Plant-based meat alternatives are healthier
Products like Impossible Burger and Beyond Meat are clearly better for the environment than conventionally raised beef, but their health effects remain uncertain. Most nutrients in plant-based alternatives are, by design, similar to meat. Using genetically engineered yeast, Impossible even adds heme iron. These products also pack a lot of salt. And, like many other ultra-processed foods, they may lead to higher calorie intake and weight gain.

So, what are the facts?
Fact: Processed meats are bad for health
Processed meats contain problematic preservatives. Even those labelled “no nitrates or nitrites added” contain nitrite rich fermented celery powder. Besides sodium, nitrites and heme, processed meats can contain other carcinogens, produced by charring, smoking or high-temperature frying or grilling. These compounds may not only harm the person who eats these products; they can also cross the placenta and harm a fetus.

Fact: A meatless diet is not, by itself, a healthy diet
Most diet-related diseases are caused by to