Is red meat bad for your health?
Researchers say that red meat contains important nutrients, including protein, vitamin B-12, and iron. However, there is evidence to suggest that eating a lot of red meat can raise a person's risk of certain cancers, heart disease, and other health concerns.
This article looks at what the research says, official dietary recommendations, and what amount of red meat might be healthful.
The focus of this article is on the health impacts of red meat. It does not address the ethical and environmental arguments around the consumption of red meat.
How does red meat affect health?
Eating red meat may increase a person's risk of developing heart disease or cancer.
Specialists usually classify red meat as muscle meat from beef, pork, lamb, goat, or other land mammals.
On one hand, red meat is a good source of certain nutrients, especially vitamin B-12 and iron. The human body needs these nutrients to produce new red blood cells.
Red meat is also high in protein, which is necessary for building muscle, bone, other tissues, and enzymes.
To further complicate the issue, some studies suggest that the type of red meat a person eats makes the most difference.
Leaner cuts of unprocessed red meat, such as sirloin steaks or pork tenderloin, may be more healthful than other types. This is because they are unprocessed and do not contain excess salt, fat, or preservatives.
Processed red meats — including bacon, hot dogs, sausage, bologna, salami, and similar meats — appear to carry the highest risk of health problems.
Is red meat nutritious?
Red meat contains nutrients that are beneficial to health, including iron, vitamin B-12, and zinc.
Animal based foods, such as meat and dairy, are the main dietary sources of vitamin B-12. For this reason, people who follow a vegetarian or vegan diet may need to take supplemental B-12 in order to prevent B-12 deficiency anemia.
According to the United States Department of Agriculture, one 3.5-ounce (oz) or 100-gram (g) serving of uncooked ground beef contains:
- 247 calories
- 19.07 g of fat
- 17.44 g of protein
- 1.97 milligrams (mg) of iron
- 274 mg of potassium
- 4.23 mg of zinc
- 2.15 micrograms of vitamin B-12
Many factors can affect the nutritional value of a specific piece of meat. For example, cuts from different parts of the animal vary in their calorie and fat content. Also, the way the farmer raised the animal, the animal's diet, and even the animal's age and sex can affect the nutritional value of the meat.
The National Institutes of Health (NIH) list some types of red meat as good sources of heme iron. Heme iron is only present in meat, poultry, and seafood. Nonheme iron occurs in plants and iron fortified foods, such as cereals and plant milks.
The NIH state that heme iron is more bioavailable, which means that the body can use it more easily. Although many people get enough iron from their diets, the NIH say that certain people are at risk of iron deficiency, including:
- young children
- people with heavy periods
- pregnant women
Heart disease and saturated fat
Nuts and beans are healthful plant based sources of protein.
Many different studies have suggested that eating red meat regularly can lead to a higher risk of heart disease. For years, experts have believed that the link between red meat consumption and heart disease is due to the saturated fat that is present in red meat.
The American Heart Association (AHA) claim that red meats generally have more saturated fat than other sources of protein, such as chicken, fish, or legumes.
They suggest that eating high amounts of saturated fat and any amount of trans fat can raise a person's cholesterol levels and increase their risk of heart disease. They therefore recommend that people limit the amount of red meat they eat and encourage people to choose lean cuts of meat.
That being said, red meat is not the primary source of trans fats in the Western diet. Packaged, processed, and fried foods tend to contain the most.
The AHA also explain that beans and legumes are heart-healthy alternative sources of protein. Examples include:
- pinto beans
- kidney beans
- garbanzo beans, or chickpeas
- lentils, split peas, and black eyed peas
A meta-analysis in the journal Circulation looked at 36 different studies. It concluded that replacing red meat with high quality plant protein sources — but not low quality carbohydrates — led to "more favorable" concentrations of fat in the blood.
The meta-analysis also found that there were not significant improvements in total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, or blood pressure between the red meat and animal protein diet groups.
Other studies have questioned the notion that saturated fat has links with heart disease. The authors of a review of heart disease risk state that researchers have exaggerated the role of saturated fat in the development of heart disease.
Also, a team of cardiologists wrote an article stating that the consumption of saturated fat does not clog the arteries or increase the risk of heart disease. Another article says that numerous analyses and reviews do not support the notion that eating saturated fat has links with heart disease.
All things considered, there is evidence both for and against saturated fats playing a role in heart disease. Research is ongoing.
Heart disease and trimethylamine N-oxide
Some studies have suggested that aside from the saturated fats debate, red meat still has other potential heart disease risks.
A recent study found that people who eat red meat regularly have higher levels of a metabolite called trimethylamine N-oxide (TMAO). Bacteria in the gut produce TMAO during digestion. It is a toxin that researchers have linked to an increased risk of heart disease death.
This study shows that people who ate red meat had triple the levels of TMAO compared with those who ate white meat or plant based proteins. However, their TMAO levels returned to normal around 4 weeks after stopping eating red meat.
Cancer and mortality
Some recent research suggests that eating red meat regularly could increase the risk of cancer or death. The findings of specific studies vary, however.
One 2015 paper states that red meat is "probably carcinogenic to humans," and that processed meat is "carcinogenic to humans." This is consistent with the World Health Organization's (WHO) classifications.
Specifically, the paper states that based on several large studies, people who ate more red meat were more likely to develop colorectal cancer. The risk was higher for both red meat and processed meat, though processed meat seemed to raise the risk more.
The authors say that meat processing methods, such as curing and smoking, can create cancer causing chemicals. This may be why researchers have linked processed meat with greater health risks than unprocessed meat.
Other research has also shown links between red meat and cancer. For example:
- One study tracked over 42,000 women for 7 years and found that higher consumption of red meat had links with a higher risk of invasive breast cancer. Conversely, women who ate poultry instead of red meat had a lower risk.
- Another study, which followed 53,000 women and 27,000 men, found that those who ate red meat, especially processed meat, had higher mortality rates over the course of 8 years. The participants did not have heart disease or cancer when the study began. Increases of "at least half a serving" of red meat per day had a 10% higher mortality risk.
- A large study that followed more than 120,000 men and women for 10 years found that only processed red meat, not unprocessed types, was associated with a higher risk of death.
Cooking methods and cancer
Using a different cooking technique can help reduce the levels of cancer causing chemicals in the meat.
When a person cooks meat at a high temperature, such as by pan frying it or grilling it over an open flame, certain chemicals form in the meat. These chemicals, called heterocyclic amines and polycyclic aromatic hydrocarbons, may cause changes in DNA that lead to cancer.
Exposure to these chemicals can cause cancer in animals, but experts do not know for certain that this also happens in humans.
The National Cancer Institute say that people can reduce their exposure to these chemicals by:
- not cooking meat, including white meat, over an open flame or on a very hot metal surface
- precooking meat in a microwave to reduce the time a person needs to cook it over high heat
- turning and flipping the meat regularly during cooking
- not eating charred portions of meat
Serving antioxidant rich vegetables, such as dark leafy greens, with cooked meats is another good way to support the body.
How much red meat is too much?
The guidelines for how much red meat is healthful vary from organization to organization.
The World Cancer Research Fund and American Institute for Cancer Research (AICR) say that if a person eats red meat, they should limit their intake to 3 servings per week. This would be equivalent to about 12–18 oz per week. They also say to eat little, "if any," processed meat.
They explain that meat can be a valuable source of nutrients, but that people do not need to eat meat — red or otherwise — to be healthy. In fact, they say that "people can obtain adequate protein from a mixture of pulses (legumes) and cereals (grains)."
The AHA are less specific in their meat recommendations. They say that people should cut back on meat and only eat it "once in a while," sticking to lean cuts and portions that are no larger than 6 oz.
However, not everyone agrees that people should avoid or limit red meat.
One article states that an "overzealous focus" on limiting red meat can lead people to eat less nutritious foods, such as highly processed junk foods. Also, because researchers have linked highly processed foods with numerous health problems, this may not be a positive trade-off.
The article also states that "unprocessed red meats are one of the best sources of high quality protein and make important contributions to nutrient intakes." They can also keep triglyceride levels lower than high carbohydrate diets do.
It is difficult to link one food or food group to health problems. This is because a range of other factors — including genetics, environment, health history, stress levels, sleep quality, lifestyle, and other dietary factors — may play a role in whether or not a person develops a specific condition or disease.
Still, the body of evidence claiming that eating high amounts of red meat, especially processed meat, could lead to health problems is growing.
For this reason, people may wish to cut back on red and processed meat and to focus on foods that contain antioxidants and nutrients — such as fruits and vegetables — that can help prevent health problems.
It is important to remember that substituting red meat for processed, low quality carbohydrates can worsen insulin sensitivity, triglyceride levels, and overall health.