The sweet potatoes that we are talking about have a deep purple skin as well as deep purple flesh. Deep purple all the way through. We've been growing these for about 4 years.
We are able to store these potatoes until early spring. Before they start to sprout, I make and freeze enough mashed purple sweet potatoes to last until the next harvest.
I have cut and pasted some of the more interesting info that I found online below along with links.
Mac
More antioxidants than blueberries
"Blueberries are well known for their high antioxidant levels, however, the Okinawan sweet potato actually has 150 percent more antioxidants than blueberries.
6 Antioxidants help to guard against cardiovascular disease and cancer."
http://www.downtoearth.org/health/nutrition/okinawan-sweet-potato-purple-powerhouse-nutrition
Antioxidants
"Yet beta-carotene only begins to tell the story of sweet potato
antioxidants.
Particularly in purple-fleshed sweet potato, antioxidant
anthocyanin pigments are abundant. Cyanidins and peonidins are concentrated in
the starchy core of part of purple-fleshed sweet potatoes, and these
antioxidant nutrients may be even more concentrated in the flesh than in the
skin. That's sweet potatoes have genes (
IbMYB1 and
IbMYB2)
that are specialized for the production of anthocyanin pigments in the fleshy
part of the tuber. Ordinary, we have to rely on the skins of foods for this
same level of anthocyanin antioxidants. But not in the case of sweet potatoes!
Extracts from the highly pigmented and colorful purple-fleshed and
purple-skinned sweet potatoes have been shown in research studies to increased
the activity of two key antioxidant enzymes—copper/zinc superoxide dismutase
(Cu/Zn-SOD) and catalase (CAT).
Recent research has shown that particularly when passing through our
digestive tract, sweet potato cyanidins and peonidins and other color-related
phytonutrients may be able to lower the potential health risk posed by heavy
metals and oxygen radicals. That risk reduction might be important not only for
individuals at risk of digestive tract problems but for all persons wanting to
reduce the potential risk posed by the presence of heavy metal residues (like
small amounts of mercury or cadmium or arsenic) in their diet.
Storage proteins in sweet potato also have important antioxidant properties.
These storage proteins—called sporamins—get produced by sweet potato plants
whenever the plants are subjected to physical damage. Their ability to help the
plants heal from this damage is significantly related to their role as
antioxidants. Especially when sweet potato is being digested inside of our
gastrointestinal tract, we may get some of these same antioxidant benefits.
Anti-Inflammatory Nutrients
in Sweet Potato
Anthocyanin and other color-related pigments in sweet potato are equally
valuable for their anti-inflammatory health benefits. In the case of
inflammation, scientists understand even more about the amazing properties of
this tuber. In animal studies, activation of nuclear factor-kappa B (NF-kB);
activation of inducible nitric oxide synthase (iNOS), and cyclooxygenase-2
(COX-2); and formation of malondialdehyde (MDA) have all be shown to get
reduced following consumption of either sweet potato or its color-containing
extracts. Since each of these events can play a key role in the development of
unwanted inflammation, their reduction by sweet potato phytonutrients marks a
clear role for this food in inflammation-related health problems. In animal
studies, reduced inflammation following sweet potato consumption has been shown
in brain tissue and nerve tissue throughout the body.
What's equally fascinating about color-related sweet potato phytonutrients
is their impact on fibrinogen. Fibrinogen is one of the key glycoproteins in
the body that is required for successful blood clotting. With the help of a
coagulation factor called thrombin, fibronogen gets converted into fibrin
during the blood clotting process. Balanced amounts of fibrinogen, thrombin and
fibrin are a key part of the body's health and its ability to close off wounds
and stop loss of blood. However, excess amounts of these clotting-related
molecules may sometimes pose a health risk. For example, excess presence of
fibrinogen and fibrin can trigger unwanted secretion of pro-inflammatory
molecules (including cytokines and chemokines). In animal studies, too much
fibrin in the central nervous system has been associated with breakdown of the
myelin sheath that surrounds the nerves and allows them to conduct electrical
signals properly. If fibrin excess can trigger unwanted inflammation in nerve
tissue and increase breakdown of the myelin wrapping the nerve cells (a process
that is usually referred to as demyelination), health problems like multiple
sclerosis (in which there is breakdown of the myelin nerve sheath) may be
lessened through reduction of excess fibrinogen and/or fibrin. In preliminary
animal studies, intake of sweet potato color extracts have been shown to
accomplish exactly those results: reduction of inflammation, and simultaneous
reduction of fibronogen levels. We look forward to exciting new research in
this area of sweet potato's anti-inflammatory benefits.
Potential
Improvement of Blood Sugar Regulation
Many people think about starchy root vegetables as a food group that could
not possibly be helpful for controlling their blood sugar. That's because many
people realize that food starches can be converted by our digestive tract into
simple sugars. If foods are especially concentrated in starch, there can often
be a risk of too much simple sugar release in our digestive tract and too much
pressure upon our bloodstream to uptake more sugar. (The result in this
situation would be an overly quick elevation of our blood sugar level.) What's
fascinating about sweet potatoes is their ability to potentially
improve blood
sugar regulation—even in persons with type 2 diabetes— in spite of their
glycemic index (GI) rating of medium. (Sweet potatoes are one of four WHFoods
vegetables that have a GI ranking of medium. The other three vegetables are
beets, corn, and leeks.) The 6.6 grams of dietary fiber in a medium sweet
potato are definitely a plus in terms of blood sugar regulation, since they
help steady the pace of digestion. But recent research has also shown that
extracts from sweet potatoes can significantly increase blood levels of
adiponectin in persons with type 2 diabetes. Adiponectin is a protein hormone
produced by our fat cells, and it serves as an important modifier of insulin
metabolism. Persons with poorly-regulated insulin metabolism and insulin
insensitivity tend to have lower levels of adiponectin, and persons with
healthier insulin metabolism tend to have higher levels. While more research on
much larger groups of individuals to further evaluate and confirm these blood
sugar regulating benefits, this area of health research is an especially
exciting one for anyone who loves sweet potatoes but is nevertheless concerned
about healthy blood sugar regulation.
Other Potential
Health Benefits
One of the more intriguing nutrient groups provided by sweet potatoes—yet
one of the least studied from a health standpoint—are the resin glycosides.
These nutrients are sugar-related and starch-related molecules that are unusual
in their arrangement of carbohydrate-related components, and also in their
inclusion of some non-carbohydrate molecules. In sweet potatoes, researchers
have long been aware of one group of resin glycosides called batatins
(including batatin I and batatin II). But only recently have researchers
discovered a related group of glycosides in sweet potato called batatosides
(including batatodide III, batatoside IV, and batatoside V). In lab studies,
most of these sweet potato glycosides have been shown to have antibacterial and
antifungal properties. To what extent these carbohydrate-related molecules in
sweet potatoes can provide us with health benefits in these same antibacterial
and antifungal areas is not yet clear. But we expect to see increasing interest
in sweet potato's batatins and batatosides and their potential to support our
health."
Anthocyanins and cancer risk
"Summary: Purple sweet potatoes have high contents of anthocyanin, and anthocyanins have been epidemiologically associated with a reduced cancer risk."
Sweet potato leaves make a high quality rabbit feed.
"Sweet potato leaves are high in protein (ranging from 25-30%), similar to that of temperate legumes. Rabbits only require 16% protein in their diet for normal growth and reproduction."
http://users.tamuk.edu/kfsdl00/Meat%20Rabbits%20Finished%20on%20Sweet%20Potato%20Forage%20Looks%20Good%20in%20Texas%20Research.pdf
