People have been eating meat throughout evolution and have digestive systems well equipped to handle it.
Traditional populations like the Masai have eaten much more red meat than the average Westerner but remained in excellent health (1).
However, the meat consumed today is different than the meat people ate in the past. Back in the day, animals roamed free and ate grass, insects or other foods natural to them.
Picture a wild cow on a field 10,000 years ago, roaming free and chewing on grass and various other edible plants.
The meat from this animal is different than the meat derived from a cow that was born and raised in a factory, fed grain-based feed and given growth-promoting hormones and antibiotics.
Today, some meat products are highly processed after the animals have been slaughtered. They are smoked, cured, then treated with nitrates, preservatives and various chemicals.
Therefore, it is very important to distinguish between different types of meat:
- Processed meat: These products are usually from conventionally raised cows, then go through various processing methods. Examples include sausages and bacon.
- Conventional red meat: Conventional red meats are fairly unprocessed, but the cows are usually factory farmed. Meats that are red when raw are defined as red meats. This includes lamb, beef, pork and some others.
- White meat: Meats that are white when cooked are defined as white meats. This includes meat from poultry like chicken and turkey.
- Grass-fed, organic meat: This meat comes from animals that have been naturally fed and raised organically, without drugs and hormones. They also don't have any artificial chemicals added.
When examining the health effects of meat, it's important to realize that not all meat is created equal.
Many studies on red meat, especially those conducted in the US, primarily examine meat from factory-farmed animals that have been fed grain-based feeds.
SUMMARYIt’s important to make a distinction between different kinds of meat. For example, grass-fed and organic meat is nutritionally different than factory-farmed, processed meat.
Red Meat is Very Nutritious
Red meat is one of the most nutritious foods you can eat.
It is loaded with vitamins, minerals, antioxidants and various other nutrients that can have profound effects on health.
A 3.5-ounce (100-gram) portion of raw ground beef (10% fat) contains (2):
- Vitamin B3 (niacin): 25% of the RDA
- Vitamin B12 (cobalamin): 37% of the RDA (this vitamin is unattainable from plant foods)
- Vitamin B6 (pyridoxine): 18% of the RDA
- Iron: 12% of the RDA (this is high-quality heme iron, which is absorbed much better than iron from plants)
- Zinc: 32% of the RDA
- Selenium: 24% of the RDA
- Plenty of other vitamins and minerals in smaller amounts
This comes with a calorie count of 176, with 20 grams of quality animal protein and 10 grams of fat.
Red meat is also rich in important nutrients like creatine and carnosine. Non-meat eaters are often low in these nutrients, which may potentially affect muscle and brain function (3, 4, 5).
Grass-fed beef is even more nutritious than grain-fed beef, containing plenty of heart-healthy omega-3s, the fatty acid CLA and higher amounts of vitamins A and E (6, 7, 8).
SUMMARYRed meat is very nutritious, especially if it comes from animals that have been naturally fed and raised. It's a great source of protein, iron, B12, zinc, creatine and various other nutrients.
Heart Disease, Diabetes and Death
The effects of red meat on health have been well studied.
However, most of these studies are so-called observational studies, which are designed to detect associations but cannot prove causation.
Several observational studies show that red meat is associated with a greater risk of cardiovascular disease, cancer and death (9).
Nevertheless, not all red meat has the same health effects.
A massive review of 20 studies including 1,218,380 individuals found that processed meat was associated with an increased risk of heart disease and diabetes. However, no association was found for unprocessed red meat (10).
In the EPIC study, a very large observational study including 448,568 people, processed meat increased the risk of death, while no effect was seen for unprocessed red meat (11).
When it comes to an increased risk of heart disease, diabetes and death, it’s crucial to distinguish between processed and unprocessed meat, as the two can have vastly different effects.
The observational studies seem to agree that processed meat (not unprocessed red meat) is associated with an increased risk of an early death and many diseases.
But even so, it’s important to keep in mind that these studies have limitations. It’s impossible to draw strong conclusions from observational studies.
The only way to establish cause and effect is to perform randomized controlled trials.
SUMMARYSome observational studies show a link between meat intake, diabetes, heart disease and death. Other studies suggest this only applies to processed meat, not unprocessed red meat.
Does red meat increase your chances of cancer?
Many observational studies show that red meat consumption is associated 1=with an increased risk of cancer (12, 13, 14).
The main type of cancer that red meat is believed to cause is colorectal cancer, the fourth most commonly diagnosed cancer in the world.
A recurrent problem in these studies is that they seem to pool together processed meat and unprocessed red meat.
Meta-analyses in which researchers analyze data from many studies show that the increased risk of colorectal cancer is very low. One meta-analysis found a weak effect for men, but no effect for women (15, 16).
Other studies suggest that it's not the meat itself, but rather harmful compounds that form when the meat is cooked, that contribute to the increased risk (17, 18).
Therefore, the cooking method may be a major determinant of the ultimate health effects of meat.
SUMMARYSeveral observational studies show that red meat eaters are at a greater risk of cancer, but larger reviews looking at the evidence as a whole show that the effect is weak and inconsistent.