Maize vs Rice - Health impact and Nutrition Comparison

Introduction

Corn, also known as maize, is a cereal grain that originates in parts of South America, particularly domesticated by indigenous people of Mexico. The production of corn surpasses that of rice, but most of the crop is used in agriculture as animal feed or to produce corn ethanol, starch and syrup, instead of directly being consumed by people as food. Corn is a warm-season annual crop, but is grown all year round in greenhouses. It is a great source of vitamins and micronutrients.

Rice is the seed of a grass species, classified as a cereal grain as well. It is said to provide about twenty percent of all human caloric intake worldwide. Rice can be grown practically in every country, but its parent species are native to eastern Asian countries and certain parts of Africa. Overall it is an easy and cheap source of calories and micronutrients all year round, with a variety of ecotypes with different textures, tastes and nutritional values.

In this analysis we discuss what qualities do the two foods have in common, but more importantly what are their main nutritional differences and health impacts.

Nutrition

Corn is richer in sugars and protein but overall rice is higher in carbs, due to starch and calories. Corn has a lower glycemic index, while rice is recommended in a low fats diet.

Vitamins

Corn contains vitamin A, vitamin E, vitamin C and vitamin K, whereas rice is completely absent of those. The former is also richer in B vitamins, vitamins B2(riboflavin), B3(niacin), B5(pantothenic acid)  in particular, except for vitamin B9(folic acid) which is present in rice, but not corn.

Minerals

When it comes to micronutrients, the winner depends on what you’re looking for, corn contains more potassium, magnesium, phosphorus and sodium, whereas rice is richer in iron, calcium and copper. Both foods are equal in amounts of zinc contained.

When speaking of nutrients, it is important to pay attention to fortification (enrichment or the adding of micronutrients to food). In more recent years, World Health Organisation (WHO) has come up with guidelines for fortification of rice with iron, zinc, vitamin A and B-complex vitamins, to reduce malnourishment.

Starch or amylum, a polymeric carbohydrate, can be extracted from both plants, but the two have different physicochemical and morphological properties. Corn starch has a greater average granule size and amylose content. Rice starches are more difficult to extract and profitably use in products, it cooks at a higher temperature and does not form a gel as strong. That is why corn starch is much more common in households.

Health impact

Corn is higher in fiber, as well as choline, which is an essential nutrient for cellular growth, DNA synthesis and metabolism, that the body gets mostly from dietary sources. There are two types of choline: fat-soluble and water-soluble. The choline in corn is fat-soluble, so the body absorbs it from the gastrointestinal tract. Choline is an essential nutrient for fetal brain development and greatly improves cognitive functioning in older people. It is a part of an important neurotransmitter acetylcholine. Choline deficiency can lead to fatty liver disease and liver damage, muscle damage and cognitive decline, among other issues.So corn can provide nutrients that are necessary in every system of the body.

 Fiber is important for the health of the gastrointestinal tract, controlling blood sugar and cholesterol levels. It is refined and processed white rice that misses this element, whilst brown rice contains much more of it. To see more information about the differences of these two types of rice you can look at our White rice vs Brown rice comparison. https://foodstruct.com/compare/rice-vs-rice-brown-long-grain-cooked

Corn is also higher in most vitamins, predominantly vitamins A, K, C, B2 and B5, that play a large role in human metabolism. Vitamin A is a fat soluble vitamin that plays a big role in growth and development, the immune system and vision. It is partly responsible for the yellow pigment of corn. The retina uses vitamin A to synthesize rhodopsin that later breaks down when absorbing light, sending a neuronal signal to the brain about the picture in front of your eye. Therefore vitamin A deficiency leads to reversible vision loss, especially in dim lit spaces, as well as immune system and skin issues. Vitamin K is an important part of the body’s coagulative response, creating blood clots and preventing excessive bleeding. Vitamin C or ascorbic acid, is only found in sweet corn and is widely known for its important role in the immune system, it is also involved in tissue reparation, the synthesis of certain neurotransmitters. Corn has the highest total antioxidant activity due to its vitamin C among other grains such as rice and wheat. Vitamin B2, also known as riboflavin, is required for cellular respiration. Its deficiency causes a variety of issues such as migraines and stomatitis. It is also said to lower the risk of colorectal cancer. Corn, being the source of these vitamins can prevent deficiencies, as well as play a great role in the healthy processes of the organism. Overall scientific evidence suggests that the right amount of corn consumption leads to a reduced risk of developing chronic diseases: cardiovascular, type 2 diabetes, obesity and digestive issues.

As good as corn is for human health it has been known to cause a malnutrition issue if overused, stemming from its lack of a few amino acids, namely lysine and tryptophan. Corn can also easily lose its vitamin B3, also known as niacin, if cooked improperly, a process called nixtamalization. Niacin deficiency, especially combined with a tryptophan deficiency causes a disease called pellagra.The main symptoms include diarrhea, inflamed skin and cognitive issues. The lack of tryptophan leads to low serotonin levels, leading to depression. It is often referred to as the disease of four “D”s: diarrhea, dermatitis, dementia and death.

Some African countries where the people endure famine and use corn as their main food source, suffer from a disease called Kwashiorkor, as a result of severe protein malnutrition. It mostly affects infants and children and is rarely seen in developed countries.

Rice, on the other hand, contains less sugar and sodium and a major vitamin that corn misses, vitamin B9 (folic acid), as well as vitamins B1, B2 and B3. Vitamin B9, also known as folic acid or folacin, plays an important role in the formation of DNA and RNA necessary for normal cell division and formation of human germ cells. It also controls the level of amino acid homocysteine in the blood. High levels of homocysteine in the blood are associated with heart disease. Vitamin B9 deficiency also leads to megaloblastic anemia. Pregnant women with low levels of folic acid are at risk of having children with neural tube defects. As previously discussed vitamin B3 deficiency causes pellagra, which is a large issue if one misuses corn, but rice does not create the same problem. Even though rice has the essential amino acid tryptophan, like corn it also misses lysine, unless it has undergone biofortification. Vitamin B1 or thiamine deficiency symptoms such as muscle weakness and neuritis can be partially treated with some types of rice with a high thiamine content.

A negative aspect of overusing rice or producing it in wrong conditions is the arsenic concern. It is a natural found resource in the soil and can be found in rice, but it can turn into a larger issue when it is used for making infant food. High levels of arsenic is considered oncogenic as well as playing a role in some coronary diseases. Rice plants can sometimes be infected  with different microorganisms such as the bacterium called Bacillus cereus, the spores of which can later be contained in cooked rice, producing an emetic (vomit inducing) toxin.

Summary

In summary, both foods contain important vitamins and minerals and can lead to negative effects if overused. Corn being predominantly rich in sugar and protein, vitamins A, C, K, E, B2, B5, also choline and fiber, whereas rice is higher in iron, calcium, vitamin B9, carbs and overall calories. So the choice depends on what the organism needs.

Sources

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