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During the past few years, red meat has received some bad press. There’s conflicting data out there about its benefits and drawbacks.
Cardiovascular disease and colon cancer, in particular, have been linked to red meat intake by several studies. However, several of these studies have limitations and are challenged by opposing well done meta-analyses and systemic reviews.
In a large study published in the American Journal of Clinical Nutrition they found that that there was no difference in mortality between vegetarians and meat eaters. Another study published in the American Journal of Clinical Nutrition found that the risk of colorectal cancer was not associated with saturated fat or red meat intake.
I hope to present both sides of the research while also helping you understand the science and nutritional composition of red meat so that you can make a personal decision that aligns with your health goals.
“Red meat” is the term used to classify meats such as beef, pork, lamb, and veal. These meats all contain high levels of myoglobin, which gives off a red tint when exposed to oxygen (3). We consume these red meats in their unprocessed forms such as steak, pork chops, and hamburgers. Processed red meats, on the other hand, have undergone treatments like curing or salting to extend their shelf lives. Chemical preservatives may be added as well to improve color, flavor and quality, but can sometimes impart unintended health consequences. Processed red meats are usually higher in sodium and nitrates, and includes include things like ham, bacon, sausages and hot dogs. A large systematic review found that the intake of processed meats, but not red meats, was associated with higher incidence of coronary heart disease and diabetes mellitus.
Protein
Red meat is considered to be a high biological value protein source, meaning that it contains all 8 essential amino acids (EAAs) required by adults and the 9 required by children. These EAAs can help the body to build muscle and assist in repair from normal daily breakdown in the body, as well as prevent or slow the progression of sarcopenia, the age-related loss of muscle mass. Increasing the amount of high biological value protein sources consumed in middle age and beyond is important for maintaining adequate strength and muscle mass, which will in turn help to maintain quality of life.
While protein is a necessary dietary component for our survival, very high protein intake has been observed to lead to poor health outcomes. Based on recent studies, scientists have determined that there is in fact a method of communication between gut bacteria and the host that is mediated specifically by protein. They’ve found that consuming a high protein diet (up to 60% of total calories) can have a huge impact on the gut microbiome, altering the types of activities being performed by the bacteria present (5). Other studies have found that high protein feeding in mice led to increased production and secretion of IgA, an antibody that plays a key role in immune function, as well as some cytokines. Elevated levels of these molecules are associated with inflammation, suggesting that excess protein intake may increase inflammation in the body. Branched chain amino acids (BCAAs), an important component of proteins, have been positively associated with insulin resistance and high hemoglobin A1c levels, and high plasma levels of BCAAs have been linked with the development of type 2 diabetes. Conversely, higher carbohydrate diets have been observed to reduce inflammatory symptoms, which scientists conjecture is due to the production of short chain fatty acids (SCFAs) during their digestion.
Iron
Iron is an important component of the hemoglobin molecule, which is the part of the red blood cell that helps to transport oxygen throughout the body. Iron can also help to metabolize carbohydrates and fats into energy. The iron in red meat is known as heme iron, which is the form that is most easily absorbed by the body. Because of the high bioavailability of the iron in red meat, it can be an important dietary component for those suffering from iron deficiency anemia, or who have low iron levels. One study published in the Journal of Pediatric Gastroenterology and Nutrition looked at 263 healthy children between the ages of 1.5 – 6 years. Using blood samples and food frequency questionnaires, researchers determined that children with extremely low red meat intake had a 4-fold higher prevalence of iron deficiency anemia than those who consumed >/=2 servings per week, demonstrating its potential protective action against this condition. However, raised iron concentrations can contribute to an increased risk of type 2 diabetes development because of its pro-oxidative properties – the metabolism of iron can create reactive oxygen species, which inhibit insulin binding, affecting blood glucose control. If you’re interested in checking your iron levels, InsightTracker offers blood tests for a wide variety of biomarkers, and provides personalized information to you based on your results. Use the code NUTRITIONREWIRED for 20% off your plan plus a FREE InnerAge 2.0 ($179 value).
Fatty Acids
The composition of fatty acids in red meat varies depending on the proportions of fat and lean meat present in the specific cut. Lean meat is higher in polyunsaturated fatty acids (PUFAs) than untrimmed meats, which contain more saturated fats. PUFAs are considered “healthy fats”, providing anti-inflammatory benefits, which can help to positively impact long-term health. High saturated fat intake, on the other hand, has been linked to several health problems, such as heart disease. Therefore, if you’re going to eat red meat, choose leaner cuts such as top sirloin steak for more health benefits.
Carcinogens
Barbequing is a tasty and common way to cook meat. While the method of grilling foods isn’t inherently harmful, when meats are cooked at high temperatures for extended periods of time, heterocyclic amines (HAAs) are formed, and are thought to increase the risk of cancer development in humans. High heat cooking can also create polycyclic aromatic hydrocarbons (PAHs), which are considered to be genotoxic, meaning that they can damage the DNA or chromosomes and lead to potentially inheritable genetic mutations (3,9). Exposure to high temperatures for short periods of time can also create potentially harmful byproducts, such as advanced glycation end-products (AGEs), which have been found to increase inflammatory and oxidative processes and progression of type 2 diabetes.
Additives
Nitrites and nitrates are used in processed meats as a preservative and to inhibit botulism, a potentially deadly condition originating from the toxins released by a microorganism. However, these additives can be toxic to the beta cells of the pancreas, decreasing insulin secretion and thereby increasing the risk of development of type 2 diabetes. These additives also may contribute to inflammation, and even damage to the DNA. Levels of sodium, another preservative, in processed red meats are often very high, which can also negatively impact insulin sensitivity. Because of their high sodium content, processed red meats should be limited for those with conditions like hypertension or congestive heart failure.
If you’re feeling overwhelmed with information, that’s okay – here are the key takeaways from this article:
Pros:
- Red meat contains all 8 essential amino acids, and is therefore considered a “high biological value” protein source.
- It’s also a great source of iron, which is necessary for supplying the body with oxygen.In addition to iron, red meat is high in vitamin B12, a vitamin that aids with brain and nervous system function and the formation of blood; and in zinc, which keeps your immune system working properly.
- Red meat provides a great source of protein too, an important nutrient. Protein is broken down into amino acids that assist with everything from digesting food to repairing body tissue in the body.
- Lean cuts of red meat contain higher levels of polyunsaturated fatty acids than untrimmed cuts, so they can be chosen as a healthier red meat option.
Cons:
- Excess protein intake, especially from processed meats, can alter the microbiome and result in heightened immune response, leading to inflammation. It can also increase the risk of developing type 2 diabetes, as can excess iron intake.
- High temperature cooking of red meats can lead to the formation of several carcinogenic compounds, which have been linked to cancer development, DNA damage, and type 2 diabetes progression, among other things.
- Some of the additives in processed red meats, such as nitrates/nitrites, can damage the beta cells of the pancreas, leading to decreased insulin secretion.
- These processed meats also often contain high levels of sodium, which is contraindicated in many medical conditions.
In summation, if you choose to consume red meat, do so in moderation. The American Heart Association and the USDA suggest that you shouldn’t consume more than 6 ounces of meat per day (that includes white meat). A 3-ounce portion is about the size of a deck of cards. InsideTracker will provide you with sensible recommendations based on your blood work. The bottom line is that red meat can be incorporated into a healthy diet—but eat it in moderation! Think about maintaining a balance between the various food groups and don’t eat too much of any one component.
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