HEALTH BENEFITS OF SWEET
POTATOES, NUTRITIONAL VALUES
POTATOES, NUTRITIONAL VALUES
ABOUT SWEET POTATOES
Sweet potatoes are a Native American plant that was the
main source of nourishment for early homesteaders and for
soldiers during the Revolutionary War. These tuberous roots
are among the most nutritious foods in the vegetable
kingdom. They are packed with calcium, potassium, and
vitamins A and C. This is why one colonial physician called
them the "vegetable indispensable." Sweet potatoes are often
confused with yams, but yams are large, starchy roots grown
in Africa and Asia. Yams can grow up to 100 pounds and are
rarely available in American supermarkets. Nutritionally, sweet
potatoes greatly outweigh yams. Because of the common use
of the term "yam," it is acceptable to use this term when
referring to sweet potatoes. Sweet potatoes contain an
enzyme that converts most of its starches into sugars as the
potato matures. This sweetness continues to increase during
storage and when they are cooked.
Nutritional Values of Sweet Potatoes
One serving size of sweet potatoes, 3.5 oz, containing 140
calories, 24 mg of sodium, 195 mg of potassium, 2 g of
dietary fiber, vitamins A and C, and small amounts of calcium
and iron.
Selection
Choose firm, dark, smooth sweet potatoes without wrinkles,
bruises, sprouts, or decay. Even if cut away, a decayed spot
may have already caused the whole potato to take on an
unpleasant flavor.
Storage
Sweet potatoes spoil rapidly. To keep them fresh, store them
in a dry, cool (55-60°) place such a cellar, pantry, or
garage. Do not store them in the refrigerator, where they will
develop a hard core and an "off" taste. If stored properly,
sweet potatoes will keep for a month or longer. At normal
room temperature, they should be used within a week of
purchase. You may brush off any excess dirt before storing,
but do not wash them until you are ready to cook them. It is
the moisture from washing that will increase their spoilage.
Preparation
Wash sweet potatoes well. Cook them whole whenever
possible as most of the nutrients are next to the skin, and
skins are easier to remove after they have been cooked.
Pierce skin with fork. Place potatoes in a pan and cook in an
oven heated to 375° F for about 45 minutes or until tender.
Cool potatoes slightly before removing skins. Sweet potatoes
can be cooked in a microwave oven to save time. Wash and
pierce potatoes, then place them on a paper towel. The
cooking time for 2 medium potatoes is on high for 5–9
minutes, and 4 potatoes, 10–13 minutes. Yellow and dark
orange sweet potatoes can be used interchangeably in
recipes. Try not to mix the two types in a single dish,
because their different textures and cooking times may affect
the outcome of the recipe. The yellow variety takes longer to
cook than the orange and will be done at the upper range of
cooking times.
Potential Health Benefits of Sweet Potatoes
Sweet Potatoes may have benefits of cancer prevention.
Japanese researchers prepared extracts of baked sweet
potato and studied its anti-cancer activities. They found that
extracts containing high phenolic compounds showed
significant radical scavenging effects against the DPPH
radicals. In addition, these extracts suppressed the
proliferation of human myelocytic leukemia HL-60 cells with
apoptosis induction in a dose-dependent manner. These
extracts also blocked TPA-induced cell transformation in
muse skin JB6 cell line. [1]
Researchers from Japan also demonstrated the potential anti-
cancer benefits of the purple sweet potato color on male rats
with cancers. They induced cancer in male rats by treating
them with DMH and PhIP, then, they supplemented the rats
with purple sweet potato color or red cabbage color. They
found cancer reduction associated with the supplements. [3]
Indian researchers studied 64 cases of gallbladder cancer and
they concluded that a significant reduction in odds ratio was
seen with the consumption of radish, green chilli and sweet
potato among vegetables, and mango, orange, melon and
papaya among fruits. [2]
What contributes to the anticancer benefits of sweet potato?
The answer is anthocyanin. Japanese researchers found that
the anthocyanins from extracts of tuber of purple sweet
potatoes (Ipomoea batatas cultivar Ayamurasaki) had strong
anti-oxidative activities. [4]
Sweet Potato is proposed to have health benefits on lipid
profiles.
Ludvik B and co-workers from University of Vienna, Austria
have reported the beneficial effects of Caiapo, the extract of
white-skinned sweet potato (ipomoea batatas), on fasting
plasma glucose, as well as on total and low-density
lipoprotein (LDL) cholesterol in type 2 diabetic patients. They
further noticed that short-term treatment with 4 g/d of the
nutraceutical Caiapo consistently improved metabolic control
in type 2 diabetic patients by decreasing insulin resistance
without affecting body weight, glucose effectiveness, or
insulin dynamics. They also did not notice any side effects
during the study. [5]
A study of rats have shown a significant increase in the
activity of glucose-6-phosphate dehydrogenase in the rats
fed phytic extract from sweet potato compared to the other
groups. Phytic acid extract consumption from sweet potato
and commercial phytic acid plus zinc supplement lowered
blood glucose levels. Thus, consumption of sweet potato
diets is linked to blood glucose level lowering. [6]
THIS ARTICLE IS FOR YOUR INFORMATION ONLY. CONSULT WITH YOUR
DOCTOR BEFORE EATING SWEET POTATOS OR IF YOU HAVE ANY
QUESTIONS. ALL RIGHTS RESERVED 2006 ZHION.
[1] Rabah IO, Hou DX, Komine S, Fujii M. Potential chemopreventive
properties of extract from baked sweet potato (Ipomoea batatas Lam. Cv.
Koganesengan). J Agric Food Chem. 2004 Nov 17;52(23):7152-7. [2] Pandey
M, Shukla VK. Diet and gallbladder cancer: a case-control study. Eur J Cancer
Prev. 2002 Aug;11(4):365-8. [3] Hagiwara A, et al, Prevention by natural
food anthocyanins, purple sweet potato color and red cabbage color, of 2-
amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-associated
colorectal carcinogenesis in rats initiated with 1,2-dimethylhydrazine. J
Toxicol Sci. 2002 Feb;27(1):57-68. [4] Kano M, et al, Antioxidative activity of
anthocyanins from purple sweet potato, Ipomoera batatas cultivar
Ayamurasaki. Biosci Biotechnol Biochem. 2005 May;69(5):979-88.[5] Ludvik
B, et al, Mode of action of ipomoea batatas (Caiapo) in type 2 diabetic
patients. Metabolism. 2003 Jul;52(7):875-80. [6] Dilworth LL, et al, The effect
of phytic acid on the levels of blood glucose and some enzymes of
carbohydrate and lipid metabolism. West Indian Med J. 2005 Mar;54(2):102-
6.
Sweet potatoes are a Native American plant that was the
main source of nourishment for early homesteaders and for
soldiers during the Revolutionary War. These tuberous roots
are among the most nutritious foods in the vegetable
kingdom. They are packed with calcium, potassium, and
vitamins A and C. This is why one colonial physician called
them the "vegetable indispensable." Sweet potatoes are often
confused with yams, but yams are large, starchy roots grown
in Africa and Asia. Yams can grow up to 100 pounds and are
rarely available in American supermarkets. Nutritionally, sweet
potatoes greatly outweigh yams. Because of the common use
of the term "yam," it is acceptable to use this term when
referring to sweet potatoes. Sweet potatoes contain an
enzyme that converts most of its starches into sugars as the
potato matures. This sweetness continues to increase during
storage and when they are cooked.
Nutritional Values of Sweet Potatoes
One serving size of sweet potatoes, 3.5 oz, containing 140
calories, 24 mg of sodium, 195 mg of potassium, 2 g of
dietary fiber, vitamins A and C, and small amounts of calcium
and iron.
Selection
Choose firm, dark, smooth sweet potatoes without wrinkles,
bruises, sprouts, or decay. Even if cut away, a decayed spot
may have already caused the whole potato to take on an
unpleasant flavor.
Storage
Sweet potatoes spoil rapidly. To keep them fresh, store them
in a dry, cool (55-60°) place such a cellar, pantry, or
garage. Do not store them in the refrigerator, where they will
develop a hard core and an "off" taste. If stored properly,
sweet potatoes will keep for a month or longer. At normal
room temperature, they should be used within a week of
purchase. You may brush off any excess dirt before storing,
but do not wash them until you are ready to cook them. It is
the moisture from washing that will increase their spoilage.
Preparation
Wash sweet potatoes well. Cook them whole whenever
possible as most of the nutrients are next to the skin, and
skins are easier to remove after they have been cooked.
Pierce skin with fork. Place potatoes in a pan and cook in an
oven heated to 375° F for about 45 minutes or until tender.
Cool potatoes slightly before removing skins. Sweet potatoes
can be cooked in a microwave oven to save time. Wash and
pierce potatoes, then place them on a paper towel. The
cooking time for 2 medium potatoes is on high for 5–9
minutes, and 4 potatoes, 10–13 minutes. Yellow and dark
orange sweet potatoes can be used interchangeably in
recipes. Try not to mix the two types in a single dish,
because their different textures and cooking times may affect
the outcome of the recipe. The yellow variety takes longer to
cook than the orange and will be done at the upper range of
cooking times.
Potential Health Benefits of Sweet Potatoes
Sweet Potatoes may have benefits of cancer prevention.
Japanese researchers prepared extracts of baked sweet
potato and studied its anti-cancer activities. They found that
extracts containing high phenolic compounds showed
significant radical scavenging effects against the DPPH
radicals. In addition, these extracts suppressed the
proliferation of human myelocytic leukemia HL-60 cells with
apoptosis induction in a dose-dependent manner. These
extracts also blocked TPA-induced cell transformation in
muse skin JB6 cell line. [1]
Researchers from Japan also demonstrated the potential anti-
cancer benefits of the purple sweet potato color on male rats
with cancers. They induced cancer in male rats by treating
them with DMH and PhIP, then, they supplemented the rats
with purple sweet potato color or red cabbage color. They
found cancer reduction associated with the supplements. [3]
Indian researchers studied 64 cases of gallbladder cancer and
they concluded that a significant reduction in odds ratio was
seen with the consumption of radish, green chilli and sweet
potato among vegetables, and mango, orange, melon and
papaya among fruits. [2]
What contributes to the anticancer benefits of sweet potato?
The answer is anthocyanin. Japanese researchers found that
the anthocyanins from extracts of tuber of purple sweet
potatoes (Ipomoea batatas cultivar Ayamurasaki) had strong
anti-oxidative activities. [4]
Sweet Potato is proposed to have health benefits on lipid
profiles.
Ludvik B and co-workers from University of Vienna, Austria
have reported the beneficial effects of Caiapo, the extract of
white-skinned sweet potato (ipomoea batatas), on fasting
plasma glucose, as well as on total and low-density
lipoprotein (LDL) cholesterol in type 2 diabetic patients. They
further noticed that short-term treatment with 4 g/d of the
nutraceutical Caiapo consistently improved metabolic control
in type 2 diabetic patients by decreasing insulin resistance
without affecting body weight, glucose effectiveness, or
insulin dynamics. They also did not notice any side effects
during the study. [5]
A study of rats have shown a significant increase in the
activity of glucose-6-phosphate dehydrogenase in the rats
fed phytic extract from sweet potato compared to the other
groups. Phytic acid extract consumption from sweet potato
and commercial phytic acid plus zinc supplement lowered
blood glucose levels. Thus, consumption of sweet potato
diets is linked to blood glucose level lowering. [6]
THIS ARTICLE IS FOR YOUR INFORMATION ONLY. CONSULT WITH YOUR
DOCTOR BEFORE EATING SWEET POTATOS OR IF YOU HAVE ANY
QUESTIONS. ALL RIGHTS RESERVED 2006 ZHION.
[1] Rabah IO, Hou DX, Komine S, Fujii M. Potential chemopreventive
properties of extract from baked sweet potato (Ipomoea batatas Lam. Cv.
Koganesengan). J Agric Food Chem. 2004 Nov 17;52(23):7152-7. [2] Pandey
M, Shukla VK. Diet and gallbladder cancer: a case-control study. Eur J Cancer
Prev. 2002 Aug;11(4):365-8. [3] Hagiwara A, et al, Prevention by natural
food anthocyanins, purple sweet potato color and red cabbage color, of 2-
amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-associated
colorectal carcinogenesis in rats initiated with 1,2-dimethylhydrazine. J
Toxicol Sci. 2002 Feb;27(1):57-68. [4] Kano M, et al, Antioxidative activity of
anthocyanins from purple sweet potato, Ipomoera batatas cultivar
Ayamurasaki. Biosci Biotechnol Biochem. 2005 May;69(5):979-88.[5] Ludvik
B, et al, Mode of action of ipomoea batatas (Caiapo) in type 2 diabetic
patients. Metabolism. 2003 Jul;52(7):875-80. [6] Dilworth LL, et al, The effect
of phytic acid on the levels of blood glucose and some enzymes of
carbohydrate and lipid metabolism. West Indian Med J. 2005 Mar;54(2):102-
6.
