| CORN nutrition values, health BENEFITS AND SIDE EFFECTS zhion@zhion.com |
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. |
 |  |  |  |
Popular
Supplements
Acetyl-L Carnitine
Acidophilus
Almond
Bladderwrack
Bilberry
Chromium
CLA
Cod Liver Oil
Coenzyme Q
Colostrum
Dandelion
EGCG
Echinacea
Eleuthero
Ellagic Acid
Eve. Primrose Oil
Fish Oil
Flaxseed
Garlic
Ginger
Ginseng
Ginkgo Biloba
Glucosamine
Gotu Kola
Guar Gum
Hyaluronic acid
Lecithin
Lycopene
Milk Thistle
Nattokinase
Passion Flower
Probiotics
Policosanol /
Polycosanol
Pycnogenol
Reishi / Lingzhi
Resveratrol
Rhodiola
Royal Jelly
Stevia
Whey
Xylitol
More Supplements
Supplements
Acetyl-L Carnitine
Acidophilus
Almond
Bladderwrack
Bilberry
Chromium
CLA
Cod Liver Oil
Coenzyme Q
Colostrum
Dandelion
EGCG
Echinacea
Eleuthero
Ellagic Acid
Eve. Primrose Oil
Fish Oil
Flaxseed
Garlic
Ginger
Ginseng
Ginkgo Biloba
Glucosamine
Gotu Kola
Guar Gum
Hyaluronic acid
Lecithin
Lycopene
Milk Thistle
Nattokinase
Passion Flower
Probiotics
Policosanol /
Polycosanol
Pycnogenol
Reishi / Lingzhi
Resveratrol
Rhodiola
Royal Jelly
Stevia
Whey
Xylitol
More Supplements
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.
 | |  | |  | |  | |  | |  | |  |