By Atli Arnarson, PhD |
July, 2015
Pork is the meat of the domestic pig (Sus domesticus).
It is the most commonly consumed red meat worldwide, especially in eastern Asia, but its consumption is forbidden in certain religions, such as Islam and Judaism.
For this reason, pork is illegal in many Islamic countries.
It is often eaten unprocessed, but cured (preserved) pork products are also very common. These include smoked pork, ham, bacon and sausages.
Being high in protein and rich in many vitamins and minerals, lean pork can be an excellent addition to a healthy diet.
Nutrition Facts
Pork Protein
Like all meat, pork is mostly made up of protein.
The protein content of lean, cooked pork is around 26% by fresh weight.
By dry weight, the protein content of lean pork can be as high as 89%, making it one of the richest dietary sources of protein.
It contains all the essential amino acids necessary for the growth and maintenance of our bodies. In fact, meat is one of the most complete dietary sources of protein.
For this reason, eating pork, or other meats, may be of particular benefit for bodybuilders, recovering athletes, post-surgical patients, or other people who need to build up or repair their muscles.
Bottom Line: High-quality protein is the main nutritional component of pork, making it useful for muscle growth and maintenance.
Pork Fat
Pork contains varying amounts of fat.
The proportion of fat in pork usually ranges from 10-16% but it can be much higher, depending on the level of trimming and various other factors.
Clarified pig fat, called lard, is sometimes used as a cooking fat.
Like other types of red meat, pork is mainly composed of saturated fats and unsaturated fats, present in approximately equal amounts.
The fatty acid composition of pork is slightly different from the meat of ruminant animals, such as beef and lamb.
It is low in conjugated linoleic acid (CLA) and is slightly richer in unsaturated fats.
Bottom Line: The fat content of pork varies. It is mainly made up of saturated and monounsaturated fats.
Vitamins and Minerals
Pork is a rich source of many different vitamins and minerals.
These are the main vitamins and minerals found in pork:
- Thiamin:Unlike other types of red meat, such as beef and lamb, pork is particularly rich in thiamin. Thiamin is one of the B-vitamins and plays an essential role in various body functions.
- Selenium:Pork is usually a rich source of selenium. The best sources of this essential mineral are animal-derived foods, such as meat, seafood, eggs, and dairy products.
- Zinc:An important mineral, abundant in pork. It is essential for a healthy brain and immune system.
- Vitamin B12:Only found in foods of animal origin, vitamin B12 is important for blood formation and brain function. Vitamin B12 deficiency may cause anemia and damage to neurons.
- Vitamin B6:A group of several related vitamins, important for the formation of red blood cells.
- Niacin:One of the B-vitamins, also called vitamin B3. It serves a variety of functions in the body and is important for growth and metabolism.
- Phosphorus:Abundant and common in most foods, phosphorus is usually a large component of people’s diets. It is essential for body growth and maintenance.
- Iron:Pork contains less iron than lamb or beef. However, the absorption of meat iron (heme-iron) from the digestive tract is very efficient and pork can be considered an outstanding source of iron.
Pork may contain useful amounts of many other vitamins and minerals.
Processed pork products, such as ham and bacon, may contain very high amounts of salt (sodium).
Bottom Line: Pork is an excellent source of many vitamins and minerals, including thiamin, zinc, vitamin B12, vitamin B6, niacin, phosphorus, and iron.
Other Meat Compounds
Similarly to plants, animal foods contain a number of bioactive substances, other than vitamins and minerals, that may affect health.
- Creatine:Abundant in meat, creatine functions as an energy source for muscles. It is a popular supplement among bodybuilders and research indicates that it may improve muscle growth and maintenance (6, 7).
- Taurine:Found in fish and meat, taurine is an antioxidant amino acid formed by our own bodies. Dietary intake of taurine may be important for heart and muscle function (8, 9, 10).
- Glutathione:An antioxidant, present in high amounts in meat, but also produced in the human body. Even though it is an essential antioxidant in the body, the role of glutathione as a zoonutrient is unclear (11, 12).
- Cholesterol:A sterol found in meat and other animal-derived foods, such asdairy products and eggs. Dietary cholesterol does not affect levels of cholesterol in the body, at least not in the majority of people (13).
Bottom Line: Pork contains a number of bioactive meat compounds, such as creatine, taurine, and glutathione.
Health Benefits of Pork
Pork is loaded with various healthy vitamins and minerals, as well as high-quality protein. Adequately cooked pork can make an excellent part of a healthy diet.
Maintenance of Muscle Mass
Along with many other animal-based foods, pork is one of the best dietary sources of high-quality protein.
With age, maintaining muscle mass is an important health consideration. Without exercise and proper diet, muscle mass naturally degenerates with age, an adverse change that is associated with many age-related health problems.
In the most severe cases, muscle wasting may lead to a condition called sarcopenia, which is characterized by very low levels of muscle mass and decreased quality of life. Sarcopenia is most common among elderly people.
High-quality protein, containing all of the essential amino acids, is very important for the maintenance of muscle mass, especially when coupled with strength training.
Inadequate intake of high-quality protein may accelerate age-related muscle degeneration, increasing the risk of sarcopenia (14).
Eating pork, or other protein-rich animal foods, is an excellent way to ensure sufficient dietary intake of high-quality protein that may help preserve muscle mass.
Bottom Line: Pork is an excellent source of high-quality protein, so it should be effective for the growth and maintenance of muscle mass.
Improved Exercise Performance
Meat consumption is not only beneficial for the maintenance of muscle mass, it may also improve muscle function and physical performance.
Aside from being rich in high-quality protein, animal muscles (meat) contain a variety of healthy nutrients that are beneficial for our own muscles. These include taurine, creatine, and beta-alanine.
Beta-alanine is an amino acid, which is used to produce carnosine in the body.
Carnosine is a substance that is important for muscle function (15, 16).
High levels of carnosine in human muscles have, in fact, been linked with reduced fatigue and improved physical performance (17, 18, 19, 20).
Following vegetarian or vegan diets, which are low in beta-alanine, may cut the amount of carnosine in muscles over time (21).
In contrast, high dietary intake of beta-alanine (from supplements) may result in significant increases in the carnosine levels of muscles (15, 17, 22, 23).
As a result, eating pork, or other rich sources of beta-alanine, may be beneficial for those who want to maximize their physical performance.
Bottom Line: Like other types of meat, pork may help improve muscle function and exercise performance.
Pork and Heart Disease
Heart disease, also called cardiovascular disease, is the main cause of premature death worldwide.
It includes adverse conditions, such as heart attacks, strokes, and high blood pressure.
There are inconsistent results from observational studies on red meat and heart disease.
Some studies have shown an increased risk for both processed and unprocessed red meat (24), whereas others showed an increased risk for processed meat only (25,26).
Others have not found any significant link (27).
However, there is no clear-cut evidence that meat, in itself, actually causes heart disease. Observational studies can only reveal possible associations, but cannot provide evidence for a direct cause-and-effect relationship.
It is clear that high meat intake is linked with unhealthy lifestyle factors, such as low consumption of fruit and vegetables, less physical activity, smoking, and overeating (28, 29, 30), and most observational studies try to correct for these factors.
Another popular explanation involves the cholesterol and saturated fat content of meat.
However, dietary cholesterol has little or no effect on cholesterol levels in blood and is not considered a health concern (13).
The link between saturated fats and heart disease is also unclear and many high-quality studies have not found any significant association (31, 32, 33).
Bottom Line: Moderate consumption of lean pork, as a part of a healthy diet, is unlikely to increase the risk of heart disease.
Pork and Cancer
Cancer is a serious disease, characterized by uncontrolled growth of cells in the body.
Many observational studies have found a link between red meat consumption and the risk of colon cancer (34, 35, 36).
Other studies found no significant effects (37, 38).
It is difficult to prove that pork actually causes cancer in humans.
This is because observational studies can only detect associations, but cannot provide evidence for a direct cause-and-effect relationship.
However, overcooked meat may contain a number of carcinogenic substances, most notably heterocyclic amines (39).
Heterocyclic amines are a family of unhealthy substances found in relatively high amounts in well-done and overcooked meat, fish, or other sources of animal protein.
They are formed when animal protein, such as pork, is exposed to very high temperatures during grilling, barbecuing, baking, or frying (40, 41).
Studies have shown that foods high in heterocyclic amines may raise the risk of several types of cancer, such as colon, breast, and prostate cancer (42, 43, 44, 45,46).
The role of meat consumption in the development of cancer is unclear. Although there is no hard evidence for the carcinogenicity of meat, there are plenty of hints.
In the context of a healthy diet, moderate intake of mildly cooked pork probably does not increase the risk of cancer, but for optimal health, it seems sensible to limit the consumption of overcooked pork.
Bottom Line: In itself, pork is probably not a risk factor for cancer. However, high consumption of overcooked pork is a cause for concern.
Adverse Effects and Individual Concerns
Eating raw or undercooked (rare) pork should be avoided altogether, especially in developing countries.
This is because raw pork may contain several types of parasites that can infect humans (47).
Pork Tapeworm
The pork tapeworm (Taenia solium) is an intestinal parasite. It sometimes reaches a length of 2-3 meters (6.5-10 feet).
Infection is very rare in developed countries. It is a greater concern in Africa, Asia, and Central and South America (47, 48, 49).
People get infected by eating raw or undercooked pork.
Most of the time, it is completely harmless and does not cause any symptoms.
However, it may occasionally lead to a disease known as cysticercosis, estimated to affect approximately 50 million people each year (47).
One of the most serious symptoms of cysticercosis is epilepsy. In fact, cysticercosis is considered to be a leading cause of acquired epilepsy (50).
Parasitic Roundworms
Trichinella is a family of parasitic roundworms that cause a disease known as trichinosis or trichinellosis.
Although trichinellosis is uncommon in developed countries, eating raw or undercooked (rare) pork may increase the risk, especially when the meat is from free-ranging, wild or backyard pigs (47).
Most often, trichinellosis has very mild symptoms, such as diarrhea, stomach pain, nausea, and heartburn, or no symptoms at all.
However, trichinellosis can develop into a serious condition, especially in elderly people.
In some cases, it may lead to weakness, muscle pain, fever, and swelling around the eyes. In worst case scenarios, it can be fatal (51).
Toxoplasmosis
Toxoplasma gondii is the scientific name of a parasitic protozoan, a single-cell “animal”, which is only visible in a microscope.
It is found worldwide, estimated to be present in approximately one third of all humans (47).
In developed countries, such as the United States, the most common cause of infection is the consumption of raw or undercooked pork (52, 53, 54).
Usually, infection with Toxoplasma gondii does not cause any symptoms, but in people with weak immune systems it may lead to a condition known as toxoplasmosis.
Symptoms of toxoplasmosis are generally mild. However, it may be detrimental to an unborn child and life-threatening in patients with weak immune systems (47, 55).
Even though pork-borne parasites are uncommon in developed countries, pork should always be eaten when well-cooked all the way through.
Bottom Line: Due to possible contamination with parasites, consumption of raw or undercooked pork should be avoided.
Summary
Pork is the world’s most popular type of meat.
It is a rich source of high-quality protein, as well as various vitamins and minerals.
For this reason, it may promote muscle growth and maintenance, and improve exercise performance.
On the negative side, consumption of both undercooked and overcooked pork should be avoided.
Overcooked pork may contain carcinogenic substances, and undercooked (or raw) pork may harbor parasites.
That being said, moderate consumption of properly prepared pork can very well fit into a healthy diet.
This article was originally published at https://authoritynutrition.com/foods/pork/