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Corn oil is an edible oil with a pleasant taste. It contains approximately 54-55% polyunsaturated fatty acids, most of which is omega-6 linoleic acid. 27-28% of this oil contains monounsaturated fatty acids mainly oleic acid. Linoleic acid is essential for cell membrane integrity, skin health and the production of eicosanoids having effects on cardiovascular health, blood pressure, triglycerides value and immunity. Corn oil diet has the both positive and negative effects on health. This oil has benefits of cholesterol-lowering effects, it helps to decrease LDL cholesterol and increase HDL cholesterol. Researches show that it has beneficial effects on reducing the risk of heart disease, because of its high unsaturated fat content. Corn oil also has potential negative effects. Generally a diet high in corn oil increases levels of carcinogenesis, which can potentially lead to liver cancer due to increasing the amount of fat deposits on the liver.
Benefits of Corn Oil
Corn oil has a number of potential benefits including its ability to prevent oxidative stress, lower serum cholesterol especially low density lipoprotein cholesterol, reduce inflammation, boost the vision health, protect the skin, and minimize allergic reactions. Mainly people use this oil as a cooking oil because of its semi-neutral flavour and cost. However some people also use this oil in topical or medicinal applications and as a massage oil. The health benefits depend upon the source and the processing method of this oil. Let’s know the several benefits of corn oil.
1. Cholesterol Lowering Effects
Corn oil is a highly effective food oil for lowering serum cholesterol. Because of its low content of saturated fatty acids which raises the cholesterol and its high content of polyunsaturated fatty acids which lowers cholesterol, consumption of corn oil can replace saturated fatty acids with polyunsaturated fatty acids, and the combination is more effective in lowering cholesterol than simple reduction of saturated fatty acids. Polyunsaturated fatty acids primarily lowers low density lipoprotein cholesterol (bad cholesterol) which is atherogenic and tends to promote the formation of fatty deposits in the arteries. Research shows that polyunsaturated fatty acids has little effect on high-density-lipoprotein cholesterol (good cholesterol) which is protective against atherosclerosis (build-up of fats, cholesterol and other substances in and on the artery walls). Polyunsaturated fatty acids generally improves the ratio of bad cholesterol to good cholesterol.
Maize oil is also compared with olive oil to find out which oil performs better in the terms of health benefits. Corn oil contains phytosterols in significant amount. These phytosterols are derived from plant sources and are similar to cholesterol in structure. Many phytosterols have powerful ability to reduce absorption of cholesterol. Some others help the body to use more cholesterol, resulting in less cholesterol in the serum.
A randomized control feeding trial study done by Kelvin C. Maki et al. compared corn oil with extra virgin olive oil in terms of improving the plasma lipoprotein lipid profile. In their study they both men and women with elevated cholesterol levels were fed 4 tablespoons/day of corn oil and extra-virgin olive oil, each for 21 days as part of a diet low in saturated fats. They concluded that consumption of corn oil is a weight-maintenance, low saturated fat and cholesterol diet and resulted in more favorable changes in bad cholesterol and other atherogenic lipids when compared with extra-virgin olive oil.
2. Improves Heart Health
Corn oil is beneficial for the cardiovascular health if consumed within limits. This oil is rich in polyunsaturated fatty acids and linoleic acid. A diet containing 8- 10% of the total energy from the polyunsaturated fatty acids is a good and healthy diet for the heart. Linoleic acid is a dietary essential that is necessary for synthesis of eicosanoids. Eicosanoids are necessary for cardiovascular, reproductive, renal, and gastrointestinal functions and resistance to disease. Although we may consume lots of fats daily, but usually our regular diet contains only about 5% of the total energy from the polyunsaturated fatty acids. So, our diet should be rich in foods containing polyunsaturated fatty acids like corn oil.
3. Maintains Blood Pressure
Maize oil is rich in polyunsaturated fatty acids which lower high blood pressure in hypertensive people. This oil is able to lower the blood pressure levels by approximately 10%. So, hypertensive people can consume corn oil in moderation without worrying.
4. Improves Skin Health
Many people use corn oil as massage oil. Although this oil is not as good as other well- known massage oils like olive, coconut and sweet almond, but it is a nice emollient. As this oil is rich in linoleic acid and vitamin E, it improves skin functioning. Because of its high linoleic acid content, this oil penetrates quickly into the skin. Antioxidants and tocopherols in the oil help to prevent skin infections and help to relieve irritation, eczema, blemishes and psoriasis.
5. Improves Vision
Corn oil is rich in flavonoids and antioxidants like lutein, which help to reduce the free radical activity in the body. Lutein is able to improve vision health and prevents the development of cataracts.
6. Reduces Inflammation and Prevents Chronic Diseases
Omega-6 fatty acids reduce inflammation when consumed in moderation. This anti- inflammatory action help to relieve the symptoms of arthritis, headache and inflammatory conditions of skin and gastrointestinal tract.
Side Effects of Corn Oil
Besides the health benefits, corn oil has many side effects including the risk of cancer, potential toxicity, weight gain, stomach irritation.
1. Risk of Cancer
Diets containing corn oil enhance the risk of cancer in many organs. The two year carcinogenicity and toxicology study done by the National Toxicology Program demonstrated that corn oil administered at a volume of 10 ml/kg of body weight, once daily or 5 days/week, was not toxic. However, it caused significant dose-related increase in incidences of cancer of pancreas in male rats. According to a research by Isabelle Berquin published in the “Journal of Clinical Investigation” in 2007, omega-6 fatty acids accelerate the growth of cancer cells and tumor growth, such as prostate tumor cells, whereas omega-3 fatty acids have protective effects against cancer. Other studies have also shown increased risk of colon cancer, lung cancer and liver cancer. So, one should consume corn oil within limits and avoid excess consumption of it.
2. Altered Balance of Omega-6 to Omega-3 fatty acids
Corn oil is rich in omega-6 linoleic acid with very little alpha linoleic acid (omega-3 fatty acid), this can lead to altered balance of omega-6 to omega-3 fatty acids. This altered balance can lead to inflammation in the body as the ratio of omega-6 to omega-3 hold the key to inflammatory conditions like arthritis, acne in the body. So, one should add omega-3 fatty acids in the diet to maintain the balance.
Maize oil is very high in calories, so excessive use of this oil can significantly boost the daily calorie intake and may cause obesity.
Usually corn oil is not toxic, if produced using cold pressed method. It can lead to serious adverse effects on various organs, if solvents are used to extract the oil. Corn oil derived from genetically modified corn (for resistance to herbicides and pesticides) is relatively new to human diets and can cause toxicity to liver, kidneys, spleen, adrenal glands and heart.
5. Reproductive effects
Corn oil is generally assumed to be biologically inert with regard to reproductive performance. Excess consumption of corn oil can cause adverse effects on female reproductive system. It can cause delay in fertilization and decreases living foetus in the uterus.
Corn oil is an edible vegetable oil mainly used in cooking. Apart from its use in cooking, it is a feedstock used for biodiesel. Other uses include industrial use like in paint, soap, salve, inks, textiles, insecticides and carrier for drug molecules in pharmaceutical preparations. Corn oil is rich in polyunsaturated fatty acids, which are essential for cell membrane integrity, production of eicosanoids, skin health and cardiovascular health. Apart from its health benefits, it has some potential negative effects. Corn oil rich diet increases the risk of liver cancer due to increasing amounts of fat deposits on the liver. It can also cause obesity. So, one should consume this oil in moderation to get its health benefits and avoid its side effects.