Lentils are edible seeds from the legume family.

They’re well known for their lens shape and sold with or without their outer husks intact.

Though they’re a common food staple in Asian and North African cuisines, the greatest production of lentils nowadays is in Canada (1).

This article tells you everything about lentils, their nutrition, benefits and how to cook them.

Lentils

Lentils are often categorized by their color, which can range from yellow and red to green, brown or black (1).

Here are some of the most common lentil types:

  • Brown: These are the most widely eaten type. They have an earthy flavor, hold their shape well during cooking and are great in stews.
  • Puy: These come from the French region Le Puy. They’re similar in color but about one-third of the size of green lentils and have a peppery taste.
  • Green: These can vary in size and are usually a cheaper alternative to Puy lentils in recipes.
  • Yellow and red: These lentils are split and cook quickly. They’re great for making dal and have a somewhat sweet and nutty flavor.
  • Beluga: These are tiny black lentils that look almost like caviar. They make a great base for warm salads.

Each lentil type has its own unique composition of antioxidants and phytochemicals (2).

Summary There are many different varieties of lentils, but brown, green, yellow and red, as well as Puy and Beluga are the most widely consumed.

Lentils are often overlooked, even though they’re an inexpensive way of getting a wide range of nutrients.

For example, they’re packed with B vitamins, magnesium, zinc and potassium.

Lentils are made up of over 25% protein, which makes them an excellent meat alternative. They’re also a great source of iron, a mineral that is sometimes lacking in vegetarian diets (1, 3).

Though different types of lentils may vary slightly in their nutrient contents, one cup (198 grams) of cooked lentils generally provides about (4):

  • Calories: 230
  • Carbs: 39.9 grams
  • Protein: 17.9 grams
  • Fat: 0.8 grams
  • Fiber: 15.6 grams
  • Thiamine: 22% of the Reference Daily Intake (RDI)
  • Niacin: 10% of the RDI
  • Vitamin B6: 18% of the RDI
  • Folate: 90% of the RDI
  • Pantothenic acid: 13% of the RDI
  • Iron: 37% of the RDI
  • Magnesium: 18% of the RDI
  • Phosphorous: 36% of the RDI
  • Potassium: 21% of the RDI
  • Zinc: 17% of the RDI
  • Copper: 25% of the RDI
  • Manganese: 49% of the RDI

Lentils are high in fiber, which supports regular bowel movements and the growth of healthy gut bacteria. Eating lentils can increase your stool weight and improve your overall gut function (5).

Furthermore, lentils contain a broad range of beneficial plant compounds called phytochemicals, many of which protect against chronic diseases, such as heart disease and type 2 diabetes (1).

Summary Lentils are an excellent source of B vitamins, iron, magnesium, potassium and zinc. They’re also a great source of plant-based protein and fiber.

Lentils are rich in polyphenols. These are a category of health-promoting phytochemicals (1).

Some of the polyphenols in lentils, such as procyanidin and flavanols, are known to have strong antioxidant, anti-inflammatory and neuroprotective effects (6, 7, 8).

One test-tube study found that lentils were able to inhibit the production of the inflammation-promoting molecule cyclooxygenase-2 (9).

In addition, when tested in the lab, the polyphenols in lentils were able to stop cancer cell growth, especially on cancerous skin cells (6).

The polyphenols in lentils may also play a part in improving blood sugar levels (1, 10, 11).

One animal study found that consuming lentils helped lower blood sugar levels and that the benefits were not solely due to the carb, protein or fat content. Though it’s not yet understood how, polyphenols may improve blood sugar levels (1, 12).

It’s also worth noting that the polyphenols in lentils don’t appear to lose their health-promoting properties after cooking (6).

This being said, these results are from laboratory and animal studies only. Human studies are needed before firm conclusions can be made on these health benefits.

Summary Lentils are a great source of health-promoting polyphenols, which have strong antioxidant and anti-inflammatory properties with potential cancer-cell inhibiting effects.

Eating lentils is associated with an overall lower risk of heart disease, as it has positive effects on several risk factors (1, 13).

One 8-week study in 48 overweight or obese people with type 2 diabetes found that eating a one-third cup (60 grams) of lentils each day increased levels of “good” HDL cholesterol and significantly reduced levels of “bad” LDL cholesterol and triglycerides (14).

Lentils may also help lower your blood pressure. A study in rats revealed that those eating lentils had greater reductions in blood pressure levels compared to those given either peas, chickpeas or beans (15).

Furthermore, proteins in lentils may be able to block the substance angiotensin I-converting enzyme (ACE), which normally triggers blood vessel constriction and thereby increases your blood pressure (16, 17).

High levels of homocysteine is another risk factor for heart disease. These can increase when your dietary folate intake is insufficient.

As lentils are a great source of folate, it’s believed that they may help prevent excess homocysteine from accumulating in your body (13).

Finally, being overweight or obese increases your risk of heart disease, but eating lentils may help lower your overall food intake. They’re very filling and appear to keep your blood sugar levels steady (10, 18, 19).

Summary Lentils may protect your heart by supporting weight loss, preventing homocysteine accumulation in your body and improving cholesterol and blood pressure levels.

Lentils contain antinutrients which can affect the absorption of other nutrients.

Trypsin Inhibitors

Lentils contain trypsin inhibitors, which block the production of the enzyme that normally helps break down protein from your diet.

However, lentils generally contain low amounts of these, and it’s unlikely that trypsin from lentils will have a major effect on your protein digestion (20).

Lectins

Lectins can resist digestion and bind to other nutrients, preventing their absorption.

Furthermore, lectins can bind to carbs on the gut wall. If they’re consumed in excess, they may disturb the gut barrier and increase intestinal permeability, a condition also known as leaky gut (21).

It’s speculated that too many lectins in the diet may increase the risk of developing an autoimmune condition, but the evidence to support this is limited (21).

That being said, lectins may possess anticancer and anti-bacterial properties (22, 23).

If you’re trying to minimize the number of lectins in your diet, try soaking lentils overnight and discard the water before cooking.

Tannins

Lentils contain tannins which can bind to proteins. This can prevent the absorption of certain nutrients (24).

In particular, there are concerns that tannins may impair iron absorption. However, research indicates that iron levels are generally not impacted by dietary tannin intake (25).

On the other hand, tannins are high in health-promoting antioxidants (25).

Phytic Acid

Phytic acids or phytates are able to bind minerals such as iron, zinc and calcium, reducing their absorption (26).

However, phytic acid is also reported to have strong antioxidant and anticancer properties (27).

Though lentils, like all legumes, contain some antinutrients, it’s important to note that dehulling and cooking the seeds greatly reduces their presence (24).

Summary Lentils contain antinutrients such as trypsin inhibitors and phytic acid, which reduce the absorption of some nutrients. Soaking and cooking lentils will minimize these, but regardless, you will still absorb the majority of your nutrients.

Lentils are easy to cook. Unlike many other legumes, they don’t require any prior soaking and can be cooked in less than 20 minutes.

It’s best to give them a rinse before cooking, to eliminate impurities.

They can then be placed in a pot, covered with water and a pinch of salt, brought to a boil and left to simmer uncovered for 15–20 minutes (28).

Your lentils should be slightly crunchy or soft, depending on your preference. Once boiled, drain and rinse in cold water to prevent further cooking.

Some lentils, like split orange lentils, cook within 5 minutes and are great when you want to prepare a last-minute meal or want to bulk-up an already cooked meal (28).

Lentils can also be cooked in big batches and used for lunch or dinner throughout the week, as they last for up to 5 days in your fridge (28).

The antinutrient content in lentils is significantly reduced by cooking. You can also soak your lentils overnight to lower levels even further (24).

Summary Lentils are easy to cook, with split lentils only taking about 5 minutes and other varieties around 20 minutes to prepare. Plus, unlike other legumes, you don’t need to soak them first.

Brown, green, yellow, red or black — lentils are low in calories, rich in iron and folate and an excellent source of protein.

They pack health-promoting polyphenols and may reduce several heart disease risk factors.

They’re easily cooked in 5–20 minutes, which — like soaking — reduces their antinutrient content.