Not many foods are worthy of the title "superfood." However, liver is one of them.
Once a popular and treasured food source, liver has fallen out of favor.
This is unfortunate because liver is a nutritional powerhouse. It's rich in protein, low in calories and packed with essential vitamins and minerals.
This article takes a detailed look at liver and why you should include it in your diet.
The liver is a vital organ in humans and animals. It is typically the largest internal organ and has many important functions, including:
- Processing digested food from the gut
- Storing glucose, iron, vitamins and other essential nutrients
- Filtering and clearing drugs and toxins from the blood
Liver, along with other organ meats, used to be a very popular food. However, muscle meats now tend to be favored over organ meats.
Regardless of its declining popularity, liver is possibly one of the most nutrient-dense foods on the planet.
People often look to fruits and vegetables for vitamins and minerals, but liver far surpasses them all in terms of nutrient content.
A small amount of liver provides well over 100% of the RDI for many essential nutrients. It is also rich in high-quality protein and low in calories (1).
Liver is cheap and readily available from grocery stores and butchers. While most animal livers can be eaten, common sources are cow, chicken, duck, lamb and pig.
Summary: Liver is possibly the most nutrient-dense food in the world. It's packed with essential nutrients, rich in protein and low in calories.
The nutritional profile of liver is exceptional.
Here are the nutrients found in a 3.5-ounce (100-gram) serving of beef liver (1):
- Vitamin B12: 3,460% of the RDI. Vitamin B12 helps the formation of red blood cells and DNA. It is also involved in healthy brain function (2).
- Vitamin A: 860–1,100% of the RDI. Vitamin A is important for normal vision, immune function and reproduction. It also helps organs like the heart and kidneys function properly (3).
- Riboflavin (B2): 210–260% of the RDI. Riboflavin is important for cellular development and function. It also helps turn food into energy (4).
- Folate (B9): 65% of the RDI. Folate is an essential nutrient that plays a role in cell growth and the formation of DNA (5).
- Iron: 80% of the RDI, or 35% for women of menstruating age. Iron is another essential nutrient that helps carry oxygen around the body. The iron in liver is heme iron, the kind most easily absorbed by the body (6, 7).
- Copper: 1,620% of the RDI. Copper acts like a key to activate a number of enzymes, which then help regulate energy production, iron metabolism and brain function (8).
- Choline: Liver provides all of the Adequate Intake (AI) for women and nearly all of it for men (AI is used because there is insufficient evidence to set an RDI). Choline is important for brain development and liver function (9, 10).
Summary: Liver provides more than the RDI for vitamin B12, vitamin A, riboflavin and copper. It is also rich in the essential nutrients folate, iron and choline.
Protein is vital to life and found in nearly every part of the body. It's required to make and repair cells and turn food into energy.
Over one-quarter of beef liver is made up of protein. Moreover, it's very high-quality protein, as it provides all of the essential amino acids.
Amino acids are the building blocks that make up proteins. Some amino acids can be made in the body, but those known as essential amino acids must come from food.
Having a higher metabolic rate means you use more calories, which can be useful for weight loss, particularly if combined with a reduced calorie intake.
Summary: Liver is a great source of high-quality protein. A high protein intake has been shown to increase metabolic rate, reduce appetite, help build muscle and preserve muscle during weight loss.
Per calorie, liver is one of the most nutrient-dense foods there is.
In fact, more commonly eaten muscle meats are nutritionally poor in comparison.
A 3.5-ounce (100-gram) sirloin steak or lamb chop contains over 200 calories.
When reducing calorie intake, you can often miss out on vital nutrition. Therefore, it is important to choose nutrient-dense foods.
While plenty of foods contain high-quality protein or vitamins and minerals, no single food contains the same variety or amount of nutrients as liver.
What's more, eating foods that are high in nutrients but low in calories has been shown to reduce hunger (18).
Liver is low in fat as well. Only around 25% of its calories come from fat, compared to 50–60% of calories in steak and lamb.
Summary: Per calorie, liver is one of the most nutrient-dense foods around. Compared to muscle meats, it is lower in calories and fat and far superior in terms of vitamins and minerals.
Many people have concerns about eating liver and wonder whether it's unhealthly.
One of the most common questions is if its cholesterol content is a problem.
While liver is high in cholesterol, this isn't an issue for most people.
Most heart disease-related cholesterol is actually produced in the body. And when you eat foods high in cholesterol, your body produces less to keep the balance (21).
However, around a quarter of the population appears to be more sensitive to cholesterol in food. For these people, eating cholesterol-rich foods can increase blood cholesterol (22).
Another common concern about eating liver is that it contains toxins.
However, the liver does not store toxins. Rather, its job is to process toxins and make them safe or turn them into something that can be safely removed from the body.
In conclusion, toxins in liver are not an issue, and it should certainly not be avoided for this reason.
Summary: Common concerns about liver include that it's high in cholesterol and may store toxins. However, its cholesterol content is not an issue for most people, and it does not store toxins.
There are certain groups who may want to avoid eating liver.
Concerns regarding the safety of liver intake during pregnancy are largely due to its vitamin A content.
High intakes of preformed vitamin A, the type found in liver, have been linked to birth defects. Yet, the exact risk is unclear, and more research is needed (23).
Nevertheless, it only takes 1 ounce (30 grams) of beef liver to reach the tolerable upper intake level for vitamin A during pregnancy. This is a very small amount, so quantities must be monitored (3).
Although it may be safe to eat a small amount of liver occasionally during pregnancy, it's necessary to be cautious.
Those With Gout
Gout is a type of arthritis caused by high levels of uric acid in the blood. Symptoms include pain, stiffness and swelling in the joints.
Liver is high in purines, which form uric acid in the body. It is therefore important to limit your intake if you have gout.
However, if you don't suffer from gout, eating liver will not necessarily cause it. While a number of factors can increase your risk of developing gout, dietary factors only account for about 12% of cases (24).
Summary: It may be best to avoid liver during pregnancy. Although liver is unlikely to cause gout, it might be sensible to avoid it if you already suffer from gout.
Liver has a unique taste, which some people love and others hate.
Here are some suggestions on how to include it in your diet:
- Pan-fried: Liver works well when pan-fried with onions.
- Spaghetti Bolognese: Liver can be chopped or minced and then mixed with regular ground beef. Calf or chicken livers work best.
- Burgers: As with Bolognese, chop or mince the liver and mix it with ground beef to make seriously nutritious burgers.
- Add plenty of seasoning: Adding lots of spices and strong flavors can help disguise its taste.
- Use lamb or calf liver: Both have a milder flavor than beef.
- Soak the liver in milk or lemon juice before cooking: This will reduce its strong flavor.
Summary: Whether you enjoy the taste of liver or not, there are many ways to include it in your diet.