| CORN nutrition values, health BENEFITS AND SIDE EFFECTS |
About Corn
Corn has been an important nutritional resource for thousands of years because of its high
protein and carbohydrate content. Corn can be traced back to Mexican or central
American cultures as early as 3400 B.C., and has become a staple among Native
American civilizations throughout the Western Hemisphere. Today, corn has less starch
and is sweeter. The sweetness accounts for its popularity among Americans. Its oil has
good sensory qualities for use in salad preparation and cooking. [1]
Varieties There are more than two hundred varieties of corn. All are good sources of
vitamin C, but only yellow kernels contain small amounts of vitamin A in the form of beta
carotene.
Selection Make sure the husks are green, tight and fresh looking. Pull the husk open to
make sure that the ear contains tightly packed rows of plump kernels. The kernels should
be smaller at the tip of each ear. Large kernels at the tip is a sign of overmaturity. If you
pinch a kernel, milky juice should spurt out. Corn should be stored in a cool area. Warmth
causes the sugar content of corn to be converted into starch. This process will cause the
ears to become less sweet.
Storage If the corn is not cooked shortly after it is purchased, then it should be stored in
refrigerator. Refrigeration helps the corn retain its sugar and vitamin C content. If you buy
unhusked corn, keep it in its husk until you are ready to cook it. This will help the corn retain
its moisture content. To fully enjoy the great taste of sweet corn, cook it as soon as
possible. The sooner the better is a good "rule of thumb."
What does one serving of corn contain?
The serving size of 1 medium ear is 90 g. It contains 130 calories, 2 g of total fat, 0 mg of
cholesterol, 25 mg of sodium, 29 g of total carbohydrate, 4 g of dietary fiber, 9 g of sugars
and 5 g of protein. Corn is also a source of anti-oxidants, iron, vitamins A and C.
De Mejia EG and Prisecaru VI from University of Illinois at Urbana-Champaign have
pointed out that corn contains important chemicals called lectins. This unique group of
proteins and glycoproteins attribute various health benefits of corns. Several lectins have
been found to possess anticancer properties in vitro, in vivo, and in human case studies;
they are used as therapeutic agents, preferentially binding to cancer cell membranes or
their receptors, causing cytotoxicity, apoptosis, and inhibition of tumor growth. [9]
What are the health benefits of corns?
Epidemiological studies have shown that consumption of corn and other grain products is
associated with reduced risk of chronic diseases. The health benefits of corn are attributed
in part to their unique phytochemical composition. [4] However, the phytochemical contents
in grains have been commonly underestimated in the literature, because bound
phytochemicals were not included. Liu RH and co-workers from Cornell University
investigated the complete phytochemical profiles in free, soluble conjugated, and insoluble
bound forms, as well as their antioxidant activities in a few uncooked whole grains. They
found that corn had the highest total phenolic content (15.55 micromol of gallic acid equiv/g
of grain) of the grains tested, followed by wheat (7.99 micromol), oats (6.53 micromol), and
rice (5.56 micromol). [4]
The major portion of phenolics in grains existed in the bound form (85% in corn, 75% in
oats and wheat, and 62% in rice). Ferulic acid was the major phenolic compound in grains
tested, with free, soluble-conjugated, and bound ferulic acids present in the ratio 0.1:1:100.
Corn had the highest total antioxidant activity (181.42 micromol of vitamin C equiv/g of
grain), followed by wheat (76.70 micromol), oats (74.67 micromol), and rice (55.77
micromol). Bound phytochemicals were the major contributors to the total antioxidant
activity: 90% in wheat, 87% in corn, 71% in rice, and 58% in oats. Bound phytochemicals
could survive stomach and intestinal digestion to reach the colon. This may partly explain
the mechanism of grain consumption in the prevention of colon cancer, other digestive
cancers, breast cancer, and prostate cancer. [4]
Why does processed sweet corn provide more benefits than raw sweet corn?
Vitamin C in apples has been found to contribute <0.4% of total antioxidant activity,
indicating most of the activity comes from other phytochemicals. This suggests that
processed fruits and vegetables may retain their antioxidant activity despite the loss of
vitamin C. Again, Liu RH and co-workers from Cornell University have shown that thermal
processing at 115 degrees C for 25 min significantly elevated the total antioxidant activity
of sweet corn by 44% and increased phytochemical content such as ferulic acid by 550%
and total phenolics by 54%, although there was a loss of 25% vitamin C. Consequently,
processed sweet corn has increased antioxidant activity equivalent to 210 mg of vitamin
C/100 g of corn compared to the remaining 3.2 mg of vitamin C in the sample that
contributed only 1.5% of its total antioxidant activity. [5]
CORN OIL
By removing free fatty acids and phospholipids from the crude corn oil, the refined corn oil
has excellent frying quality and resistance to smoking or discoloration. Because of its
pleasant taste, U.S. manufacturers like to incorporate corn oil in margarines, cooking or
salad oil.
Prior to the civil war, the main sources for starch had been wheat and potatoes. Corn
refining began with the development of the process for corn starch hydrolysis. By 1857, the
corn-starch industry reached significant proportions in the U.S. At that time, corn starch
industry has only one product-starch. Today, products derived from corn starch include
corn syrup, anhydrous sugar, maltodextrin, dextrose, glucose and starch. [8]
HEALTH BENEFITS OF CORN OIL
Dupont J and co-workers from Food and Nutrition Science Consulting, CO claimed that
refined corn oil is composed of 99% triacylglycerols with polyunsaturated fatty acid (PUFA)
59%, monounsaturated fatty acid 24%, and saturated fatty acid (SFA) 13%. The
polyunsaturated fatty acid is linoleic acid (C18: 2n-6) primarily, with a small amount of
linolenic acid (C18: 3n-3) giving a n-6/n-3 ratio of 83. Linoleic acid is essential for skin and
cell membrane integrity and icosanoids production. Icosanoids are necessary for
reproductive, cardiovascular, renal, and gastrointestinal functions and resistance to
disease. Corn oil is also a good source of of ubiquinone, alpha- and gamma-tocopherols
(vitamin E). Because the consumption of corn oil can replace saturated fatty acids with
polyunsaturated fatty acids and corn oil contains a large amount of polyunsaturated fatty
acids, corn oil has benefits of cholesterol-lowering effects, in general. [1]
Nalbone G and co-workers in France supplemented rats with a low-fat diet (2.2% lard plus
2.2% corn oil), a corn oil diet (17%), a salmon oil diet (12.5%) plus 4.5% corn oil, or a lard
diet (15%) plus 2% corn oil for eight weeks. All these diets contained 1% cholesterol. They
found that the salmon oil-diet lowered the blood cholesterol (-50%) and triglyceride (-56%)
while the corn oil lowered the triglycerides by 40%. [2]
Ostlund RE Jr and co-workers from The Washington University at St Louis have concluded
that phytosterols comprising less than 1% of commercial corn oil could substantially reduce
cholesterol absorption and this might account for part of the cholesterol-lowering activity of
corn oil from a study of healthy subjects with a mean serum cholesterol level of 5.1 mmol/L.
They found that the cholesterol absorption was 38% higher after consumption of the
sterol-free corn oil than after consumption of commercial corn oil with an identical fatty acid
content in a study of 10 healthy subjects. And, when corn oil phytosterols were added back
to sterol-free corn oil at a concentration of 150 mg/test meal, cholesterol absorption was
reduced by 12% after inclusion of 300 mg phytosterols. [3]
CORN OIL SIDE EFFECTS
Animal studies have shown that supply of polyunsaturated fatty acid is one of the
requirements for cancer growth. Wu B and co-workers from Saga Medical School, Japan
found that long-term dietary corn oil promotes azoxymethane-induced colon cancer
development partly by inhibiting the tumor suppressor gene p53-mediated
mitochondria-dependent apoptosis in a study of male Sprague-Dawley rats. [6] However,
the amount of polyunsaturated fatty acid required for cancer growth is considered to be
larger than that needed of the host. Thus, excessive intake of corn oil is not recommended.
[1] In addition, Chen F and co-workers from University of Miami observed that a significant
positive relation was found between mortality rate and the consumption of dietary corn and
wheat flour in a study of esophageal cancer cases in Shanxi Province, China. [7]
REFERENCE [1] Food uses and health effects of corn oil. J Am Coll Nutr. 1990 Oct;9(5):438-70. [2] Effects of
fish oil, corn oil and lard diets on lipid peroxidation status and glutathione peroxidase activities in rat heart.
Lipids. 1989 Mar;24(3):179-86. [3] Phytosterols that are naturally present in commercial corn oil significantly
reduce cholesterol absorption in humans. Am J Clin Nutr. 2002 Jun;75(6):1000-4. [4] Adom KK Liu RH
Antioxidant activity of grains. J Agric Food Chem. 2002 Oct 9;50(21):6182-7. [5] Dewanto V et al, Processed
sweet corn has higher antioxidant activity. J Agric Food Chem. 2002 Aug 14;50(17):4959-64. [6] Dietary corn
oil promotes colon cancer by inhibiting mitochondria-dependent apoptosis in azoxymethane-treated rats. Exp
Biol Med (Maywood). 2004 Nov;229(10):1017-25. [7] Corn and wheat-flour consumption and mortality from
esophageal cancer in Shanxi, China. Int J Cancer. 1993 Apr 1;53(6):902-6. [8] Corn Oil, Corn Refiners
Association, Online Publication, November 22, 2005. [9] Lectins as bioactive plant proteins: a potential in
cancer treatment. Crit Rev Food Sci Nutr. 2005;45(6):425-45.
Corn has been an important nutritional resource for thousands of years because of its high
protein and carbohydrate content. Corn can be traced back to Mexican or central
American cultures as early as 3400 B.C., and has become a staple among Native
American civilizations throughout the Western Hemisphere. Today, corn has less starch
and is sweeter. The sweetness accounts for its popularity among Americans. Its oil has
good sensory qualities for use in salad preparation and cooking. [1]
Varieties There are more than two hundred varieties of corn. All are good sources of
vitamin C, but only yellow kernels contain small amounts of vitamin A in the form of beta
carotene.
Selection Make sure the husks are green, tight and fresh looking. Pull the husk open to
make sure that the ear contains tightly packed rows of plump kernels. The kernels should
be smaller at the tip of each ear. Large kernels at the tip is a sign of overmaturity. If you
pinch a kernel, milky juice should spurt out. Corn should be stored in a cool area. Warmth
causes the sugar content of corn to be converted into starch. This process will cause the
ears to become less sweet.
Storage If the corn is not cooked shortly after it is purchased, then it should be stored in
refrigerator. Refrigeration helps the corn retain its sugar and vitamin C content. If you buy
unhusked corn, keep it in its husk until you are ready to cook it. This will help the corn retain
its moisture content. To fully enjoy the great taste of sweet corn, cook it as soon as
possible. The sooner the better is a good "rule of thumb."
What does one serving of corn contain?
The serving size of 1 medium ear is 90 g. It contains 130 calories, 2 g of total fat, 0 mg of
cholesterol, 25 mg of sodium, 29 g of total carbohydrate, 4 g of dietary fiber, 9 g of sugars
and 5 g of protein. Corn is also a source of anti-oxidants, iron, vitamins A and C.
De Mejia EG and Prisecaru VI from University of Illinois at Urbana-Champaign have
pointed out that corn contains important chemicals called lectins. This unique group of
proteins and glycoproteins attribute various health benefits of corns. Several lectins have
been found to possess anticancer properties in vitro, in vivo, and in human case studies;
they are used as therapeutic agents, preferentially binding to cancer cell membranes or
their receptors, causing cytotoxicity, apoptosis, and inhibition of tumor growth. [9]
What are the health benefits of corns?
Epidemiological studies have shown that consumption of corn and other grain products is
associated with reduced risk of chronic diseases. The health benefits of corn are attributed
in part to their unique phytochemical composition. [4] However, the phytochemical contents
in grains have been commonly underestimated in the literature, because bound
phytochemicals were not included. Liu RH and co-workers from Cornell University
investigated the complete phytochemical profiles in free, soluble conjugated, and insoluble
bound forms, as well as their antioxidant activities in a few uncooked whole grains. They
found that corn had the highest total phenolic content (15.55 micromol of gallic acid equiv/g
of grain) of the grains tested, followed by wheat (7.99 micromol), oats (6.53 micromol), and
rice (5.56 micromol). [4]
The major portion of phenolics in grains existed in the bound form (85% in corn, 75% in
oats and wheat, and 62% in rice). Ferulic acid was the major phenolic compound in grains
tested, with free, soluble-conjugated, and bound ferulic acids present in the ratio 0.1:1:100.
Corn had the highest total antioxidant activity (181.42 micromol of vitamin C equiv/g of
grain), followed by wheat (76.70 micromol), oats (74.67 micromol), and rice (55.77
micromol). Bound phytochemicals were the major contributors to the total antioxidant
activity: 90% in wheat, 87% in corn, 71% in rice, and 58% in oats. Bound phytochemicals
could survive stomach and intestinal digestion to reach the colon. This may partly explain
the mechanism of grain consumption in the prevention of colon cancer, other digestive
cancers, breast cancer, and prostate cancer. [4]
Why does processed sweet corn provide more benefits than raw sweet corn?
Vitamin C in apples has been found to contribute <0.4% of total antioxidant activity,
indicating most of the activity comes from other phytochemicals. This suggests that
processed fruits and vegetables may retain their antioxidant activity despite the loss of
vitamin C. Again, Liu RH and co-workers from Cornell University have shown that thermal
processing at 115 degrees C for 25 min significantly elevated the total antioxidant activity
of sweet corn by 44% and increased phytochemical content such as ferulic acid by 550%
and total phenolics by 54%, although there was a loss of 25% vitamin C. Consequently,
processed sweet corn has increased antioxidant activity equivalent to 210 mg of vitamin
C/100 g of corn compared to the remaining 3.2 mg of vitamin C in the sample that
contributed only 1.5% of its total antioxidant activity. [5]
CORN OIL
By removing free fatty acids and phospholipids from the crude corn oil, the refined corn oil
has excellent frying quality and resistance to smoking or discoloration. Because of its
pleasant taste, U.S. manufacturers like to incorporate corn oil in margarines, cooking or
salad oil.
Prior to the civil war, the main sources for starch had been wheat and potatoes. Corn
refining began with the development of the process for corn starch hydrolysis. By 1857, the
corn-starch industry reached significant proportions in the U.S. At that time, corn starch
industry has only one product-starch. Today, products derived from corn starch include
corn syrup, anhydrous sugar, maltodextrin, dextrose, glucose and starch. [8]
HEALTH BENEFITS OF CORN OIL
Dupont J and co-workers from Food and Nutrition Science Consulting, CO claimed that
refined corn oil is composed of 99% triacylglycerols with polyunsaturated fatty acid (PUFA)
59%, monounsaturated fatty acid 24%, and saturated fatty acid (SFA) 13%. The
polyunsaturated fatty acid is linoleic acid (C18: 2n-6) primarily, with a small amount of
linolenic acid (C18: 3n-3) giving a n-6/n-3 ratio of 83. Linoleic acid is essential for skin and
cell membrane integrity and icosanoids production. Icosanoids are necessary for
reproductive, cardiovascular, renal, and gastrointestinal functions and resistance to
disease. Corn oil is also a good source of of ubiquinone, alpha- and gamma-tocopherols
(vitamin E). Because the consumption of corn oil can replace saturated fatty acids with
polyunsaturated fatty acids and corn oil contains a large amount of polyunsaturated fatty
acids, corn oil has benefits of cholesterol-lowering effects, in general. [1]
Nalbone G and co-workers in France supplemented rats with a low-fat diet (2.2% lard plus
2.2% corn oil), a corn oil diet (17%), a salmon oil diet (12.5%) plus 4.5% corn oil, or a lard
diet (15%) plus 2% corn oil for eight weeks. All these diets contained 1% cholesterol. They
found that the salmon oil-diet lowered the blood cholesterol (-50%) and triglyceride (-56%)
while the corn oil lowered the triglycerides by 40%. [2]
Ostlund RE Jr and co-workers from The Washington University at St Louis have concluded
that phytosterols comprising less than 1% of commercial corn oil could substantially reduce
cholesterol absorption and this might account for part of the cholesterol-lowering activity of
corn oil from a study of healthy subjects with a mean serum cholesterol level of 5.1 mmol/L.
They found that the cholesterol absorption was 38% higher after consumption of the
sterol-free corn oil than after consumption of commercial corn oil with an identical fatty acid
content in a study of 10 healthy subjects. And, when corn oil phytosterols were added back
to sterol-free corn oil at a concentration of 150 mg/test meal, cholesterol absorption was
reduced by 12% after inclusion of 300 mg phytosterols. [3]
CORN OIL SIDE EFFECTS
Animal studies have shown that supply of polyunsaturated fatty acid is one of the
requirements for cancer growth. Wu B and co-workers from Saga Medical School, Japan
found that long-term dietary corn oil promotes azoxymethane-induced colon cancer
development partly by inhibiting the tumor suppressor gene p53-mediated
mitochondria-dependent apoptosis in a study of male Sprague-Dawley rats. [6] However,
the amount of polyunsaturated fatty acid required for cancer growth is considered to be
larger than that needed of the host. Thus, excessive intake of corn oil is not recommended.
[1] In addition, Chen F and co-workers from University of Miami observed that a significant
positive relation was found between mortality rate and the consumption of dietary corn and
wheat flour in a study of esophageal cancer cases in Shanxi Province, China. [7]
REFERENCE [1] Food uses and health effects of corn oil. J Am Coll Nutr. 1990 Oct;9(5):438-70. [2] Effects of
fish oil, corn oil and lard diets on lipid peroxidation status and glutathione peroxidase activities in rat heart.
Lipids. 1989 Mar;24(3):179-86. [3] Phytosterols that are naturally present in commercial corn oil significantly
reduce cholesterol absorption in humans. Am J Clin Nutr. 2002 Jun;75(6):1000-4. [4] Adom KK Liu RH
Antioxidant activity of grains. J Agric Food Chem. 2002 Oct 9;50(21):6182-7. [5] Dewanto V et al, Processed
sweet corn has higher antioxidant activity. J Agric Food Chem. 2002 Aug 14;50(17):4959-64. [6] Dietary corn
oil promotes colon cancer by inhibiting mitochondria-dependent apoptosis in azoxymethane-treated rats. Exp
Biol Med (Maywood). 2004 Nov;229(10):1017-25. [7] Corn and wheat-flour consumption and mortality from
esophageal cancer in Shanxi, China. Int J Cancer. 1993 Apr 1;53(6):902-6. [8] Corn Oil, Corn Refiners
Association, Online Publication, November 22, 2005. [9] Lectins as bioactive plant proteins: a potential in
cancer treatment. Crit Rev Food Sci Nutr. 2005;45(6):425-45.
| Although corn is higher in protein content than any other vegetable, it lacks the essential amino acids lysine and tryptophan. To create a complete protein, with all of the essential amino acids, corn can be combined with legumes (beans, lentils, or split peas). Legumes contain high levels of lysine and tryptophan. By combining the two, (a grain and a legume) you create a complete non-animal source of protein. |
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Discuss with your doctor before taking any alternative medicine. This article is for
reference only, it is not a medical advice. All rights reserved. Do not copy this article to
other website or blog.
reference only, it is not a medical advice. All rights reserved. Do not copy this article to
other website or blog.
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