HEALTH BENEFITS OF SWEET
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.
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.
Sweet potatoes spoil rapidly. To keep them fresh, store them in a dry,
cool (55-60Â°) 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.
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 375Â° 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 5Â–9 minutes, and
4 potatoes, 10Â–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
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.
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
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. 
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
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.
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. 
THIS ARTICLE IS FOR YOUR INFORMATION ONLY. CONSULT WITH YOUR
DOCTOR BEFORE EATING SWEET POTATOS OR IF YOU HAVE ANY QUESTIONS.
ALL RIGHTS RESERVED 2008 ZHION.
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