Are lentils and rice a complete protein?
In this article, we will address the query: “Are lentils and rice a complete protein?”. Furthermore, you will learn what is a complete protein and why combining rice and lentils can form a complete protein. This article will also give you information on health and risks of lentils and rice, and some ideas of recipes.
Are lentils and rice a complete protein?
Yes, the combination of lentils and rice create a complete protein (1,2). In fact, combining a legume and a cereal will create a complete protein. Found more information regarding this topic in the following sections!
What is a Complete Protein?
A protein is considered complete when it contains all essential amino acids. The human body needs 20 different amino acids; 11 of them are synthesized by your metabolism, but you must consume the other 9 amino acids (essential amino acids) through your food (1,2, 3).
You can find complete proteins in all animal-derived proteins such as meats, milk and dairy products, eggs, and fish. Normally, vegetable-derived proteins are deficient in one or more of the essential amino acids, hence, are considered as not complete proteins (3).
Why should you ingest complete proteins?
Amino acids are the building blocks of proteins, and proteins are the building blocks of human tissues like muscles and organs, immune cells, and enzymes used by your metabolism for food digestion, production of hormones, to produce energy, and many other functions (4).
So, if you do not consume an adequate quantity and quality of proteins, your body will not be able to do things correctly, including defending yourself against diseases; you will lose muscle mass; and if you are a child or adolescent, maybe your growth will be compromised (4).
What is the Nutritional Value of Lentils and Rice?
Even if lentils and rice are seeds or grains, they have very different nutritional value. Lentils have plenty of proteins (24 %), a moderate content of carbohydrates (63 %), and a minimum content of fats (1 %); the most important thing is that lentils are an excellent source of fiber (10 %) and minerals (5).
Regarding the protein quality, lentils (well, all legumes) lack Methionine and Cysteine, these are two essential amino acids that your body needs to produce essential molecules like glutathione, with potent antioxidant properties to protect you against diseases (3,6).
On the other hand, rice is more about carbohydrates (approximately 80 %), and in the case of the white rice, it does not have too much fiber (2 %) compared to the brown rice (3.6 %); however, rice also provides you with a modest quantity of proteins (6 %) and very little amount of fats (<1 %) (7,8).
The protein of rice, just like many other cereals, do not contain Lysine and Tryptophan, two essential amino acids that your body needs for growth and development (3,9).
Why Combining Lentils and Rice form a Complete Protein?
Combining lentils and proteins can create a complete protein because they complement each other. As it was described in the previous subheading, rice contains the amino acids that are missing in lentils, and vice versa (1,3). Think that is like a puzzle, both have one part missing, but they complement each other.
What are the Benefits of Lentils and Rice?
Consuming rice and lentils has a lot of health benefits (10,11) because they are a good source of minerals, fiber, and other types of molecules known as bioactive compounds that could improve your health. Some benefits are the following:
The fiber contained in lentils and rice helps to regulate your digestion; also, lentils have some sugars called oligosaccharides which feed your microbiota, improving your gut’s health (10).
Some of these “bioactive compounds” are very good for preventing cardiovascular diseases, for instance, saponins, tannins, and flavonoids in lentils are excellent antioxidants and for reducing your cholesterol levels in blood (11).
In the case of rice, unfortunately, all the bioactive compounds of it are discarded with the rice bran when industries process brown rice to obtain white rice (12).
What are the Risks and Precautions of Consuming Lentils and Rice?
Among the potential risks of lentils and rice, the most concerning are the presence of heavy metals or toxins. Some of these are the result of pollution, you should consider that every pollutant in the air, water, and soil eventually reaches us (13,14).
There are some studies that detected lead, arsenic, mercury, and cadmium but in small quantities; take into account that those quantities could vary if your region is very polluted or not. So you could check for the best brands of lentils and rice available in your country (13, 14).
Another thing to consider is that oligosaccharides of lentils are not digested by humans, so it is possible that once it reaches your intestine, it will be fermented and can cause flatulence or abdominal inflammation (15).
What Other Food Combinations form a Complete Protein?
You can improvise on the combination of cereals and legumes to create complete proteins, for example, you can use wheat, maize, or sorghum (as the cereal source) and combine them with legumes like pea, beans, cowpea, sesame, soybean, or chickpea (2, 3).
Here are some ideas of recipes to build a portfolio of dishes with lentils; you can add rice to those without any cereal in the recipe.
How to Prepare Lentils and Rice for Maximum Nutritional Value?
The best way to prepare lentils and rice to reach their maximum nutritional value is soaking your lentils for a few hours with plenty of water. This helps to break down those oligosaccharides and is less probable that makes you with abdominal inflammation (15).
Another tip you could adopt is to add a few drops of lime to your lentils. The ascorbic acid of lime will help your body to absorb the iron contained in the lentils (16).
In this article, we addressed the query: “Are lentils and rice a complete protein?”. Furthermore, you learned what is a complete protein and why combining rice and lentils can form a complete protein. This article also gave you information on health and risks of lentils and rice, and some ideas of recipes.
- Rafii M, Pencharz PB, Boileau K, Ball RO, Tomlinson C, Elango R, Courtney-Martin G. Metabolic Availability of Methionine Assessed Using Indicator Amino Acid Oxidation Method, Is Greater when Cooked Lentils and Steamed Rice Are Combined in the Diet of Healthy Young Men. The Journal of Nutrition, 2022, 152(6), 1467-1475.
- Temba MC, Njobeh PB, Adebo OA, Olugbile AO, Kayitesi E. The role of compositing cereals with legumes to alleviate protein energy malnutrition in Africa. Int J Food Sci Technol, 2016;51(3):543–54.
- Day L. Proteins from land plants – Potential resources for human nutrition and food security. Trends Food Sci Technol, 2013;32(1):25–42.
- Olson B, Marks DL, Grossberg AJ. Diverging metabolic programmes and behaviours during states of starvation, protein malnutrition, and cachexia. J Cachexia Sarcopenia Muscle, 2020;11(6):1429–46.
- FoodData central [Internet]. Usda.gov. [cited 26 Apr. 2023]. Available from: https://fdc.nal.usda.gov/fdc-app.html#/food-details/172420/nutrients
- Beaumont M, Blachier F. Amino acids in intestinal physiology and health. Adv Exp Med Biol, 2020;1265:1–20.
- FoodData central [Internet]. Usda.gov. [cited 26 Apr. 2023]. Available from: https://fdc.nal.usda.gov/fdc-app.html#/food-details/168883/nutrients
- Usda.gov. [cited 26 Apr. 2023]. Available from: https://fdc.nal.usda.gov/fdc-app.html#/food-details/169703/nutrients
- Xiao F, Guo F. Impacts of essential amino acids on energy balance. Mol Metab, 2022;57(101393):101393.
- Johnson N, Johnson CR, Thavarajah P, Kumar S, Thavarajah D. The roles and potential of lentil prebiotic carbohydrates in human and plant health. Plants People Planet, 2020;2(4):310–9.
- Kaale LD, Siddiq M, Hooper S. Lentil ( Lens culinaris Medik) as nutrient‐rich and versatile food legume: A review. Legum Sci, 2022.
- Saleh ASM, Wang P, Wang N, Yang L, Xiao Z. Brown rice versus white rice: Nutritional quality, potential health benefits, development of food products, and preservation technologies. Compr Rev Food Sci Food Saf, 2019;18(4):1070–96.
- Gu S-Y, Shin H-C, Kim D-J, Park SU, Kim Y-K. The content and health risk assessment of micro and toxic elements in cereals (oat and quinoa), legumes (lentil and chick pea), and seeds (chia, hemp, and flax). J Food Compost Anal, 2021;99(103881):103881.
- Sharafi K, Nodehi RN, Mahvi AH, Pirsaheb M, Nazmara S, Mahmoudi B, et al. Bioaccessibility analysis of toxic metals in consumed rice through an in vitro human digestion model – Comparison of calculated human health risk from raw, cooked and digested rice. Food Chem, 2019;299(125126):125126.
- Banti M, Bajo W. Review on Nutritional Importance and Anti-nutritional Factors of Legumes. Int. J. Nutr. Food Sci, 2020, 9(6), 138-149.
- Piskin E, Cianciosi D, Gulec S, Tomas M, Capanoglu E. Iron absorption: Factors, limitations, and improvement methods. ACS Omega, 2022;7(24):20441–56.