I have heard a lot of people ask about the difference between yams and sweet potatos. In canada we generally get more sweet potatos than yams. I know in the US more yams are readily available due to agriculture in the States. Here is a chart I found showing the differences between the two for all you hard core dieters and an interesting write up on sweet potatos.
The following information outlines several differences between SweetPotatoes and yams.
..............Factor.................SweetPotato.. ..............................Yam
Scientific name.............. Ipomoea batatas .....................Dioscorea Species
Plant Family .................Morning GloryConvolvulaceae .............Yam(Dioscoreaceae)
Plant Group............... ........Dicotyledon ....................................Monocotyledon
Chromosome number............ 2n=90 (hexaploid) ........................2n=20
Flower character ..............Monoecious ...................................Dioecious
Origin Tropical ................America(Peru,Ecuador) ...................West Africa,Asia
Historical beginning ...........Prehistoric ....................................50,000 BC
Edible storage .................organ Storage ................................root Tuber
Number/plant ......................4-10 .............................................1-5
Appearance ....................Smooth, with thin skin .......................Rough, scaly
Shape .....................Short, blocky, tapered ends Long, ...............cylindrical,some with "toes"
Dry Matter ....................22-28% ..........................................2-35%
Mouth feel ......................Moist* .............................................Dry
Taste ............................Sweet* ...........................................Starchy
Beta carotene (Vit.A) High (orange vars.)* ....................................Very low
Propagation ....................Transplants/vine cuttings ........................Tuber pieces
Growing season .................90-150 days .....................................180-360 days
Maturity ..........................None ...........................................At senescence
Storage .......................(Cured at 80-86F) 55-60F. .........................54-61 F.
Climatic requirements ...........Tropical and temperate ......................Tropical
Availability ......................Grown in USA ...............................Imported from Carribean
Health Benefits
How sweet it is for your health to eat sweet potatoes! Not only do they taste like dessert, here's the latest research on sweet potatoes surprising benefits.
Unique Proteins with Potent Antioxidant Effects
Recent research studies on sweet potato focus on two areas of unique health benefit. First are some unique root storage proteins in this food that have been observed to have significant antioxidant capacities. In one study, these proteins had about one-third the antioxidant activity of glutathione – one of the body’s most impressive internally produced antioxidants. Although future studies are needed in this area, count on these root proteins to help explain sweet potatoes' healing properties.
An "Antidiabetic" Food
Second is the recent classification of sweet potato as an “antidiabetic” food. Sweet potato has been given this label because of some recent animal studies in which sweet potato helped stabilize blood sugar levels and lowered insulin resistance. (Insulin resistance is a problem caused when cells don’t respond to the hormone insulin, which is supposed to act as a key and unlock the cell in order to allow sugar to pass from the blood into the cell). Some of its blood sugar regulatory properties may come from come from the fact that sweet potatoes are concentrated in carotenoids. Research has suggested that physiological levels, as well as dietary intake, of carotenoids may be inversely associated with insulin resistance and high blood sugar levels. Once again, more research is needed in this area, but the stage is set for sweet potato to show unique healing properties in the area of blood sugar control.
A Sweet Source of Good Nutrition
Our food ranking system also showed sweet potato to be a strong performer in terms of traditional nutrients. This root vegetable qualified as an excellent source of vitamin A (in the form of beta-carotene), a very good source of vitamin C and vitamin B6, and a good source of manganese, copper, biotin, pantothenic acid (vitamin B5), vitamin B2 and dietary fiber. How do these sweet potato components support our health?
An Antioxidant-Rich, Anti-Inflammatory FoodAs an excellent source of both vitamin A (in the form of beta-carotene) and vitamin C, sweet potatoes have healing properties as an antioxidant food. Both beta-carotene and vitamin C are very powerful antioxidants that work in the body to eliminate free radicals. Free radicals are chemicals that damage cells and cell membranes and are associated with the development of conditions like atherosclerosis, diabetic heart disease, and colon cancer. This may explain why beta-carotene and vitamin C have both been shown to be helpful for preventing these conditions.
Since these nutrients are also anti-inflammatory, they can be helpful in reducing the severity of conditions where inflammation plays a role, such as asthma, osteoarthritis, and rheumatoid arthritis. In addition, sweet potatoes are a very good source of vitamin B6, which is needed to convert homocysteine, an interim product created during an important chemical process in cells called methylation, into other benign molecules. Since high homocysteine levels are associated with an increased risk of heart attack and stroke, having a little extra vitamin B6 on hand is a good idea.
Protection against EmphysemaIf you or someone you love is a smoker, or if you are frequently exposed to secondhand smoke, then making vitamin A-rich foods, such as sweet potatoes, part of your healthy way of eating, may save your life, suggests research conducted at Kansas State University.
While studying the relationship between vitamin A, lung inflammation, and emphysema, Richard Baybutt, associate professor of nutrition at Kansas State, made a surprising discovery: a common carcinogen in cigarette smoke, benzo(a)pyrene, induces vitamin A deficiency.
Baybutt's earlier research had shown that rats fed a vitamin A-deficient diet developed emphysema. His latest animal studies indicate that not only does the benzo(a)pyrene in cigarette smoke cause vitamin A deficiency, but that a diet rich in vitamin A can help counter this effect, thus greatly reducing emphysema.
In his initial research, Baybutt took just weaned male rats and divided them into two groups, one of which was exposed to cigarette smoke, and the other to air. In the rats exposed to cigarette smoke, levels of vitamin A dropped significantly in direct correlation with their development of emphysema. In the second study, both groups of rats were exposed to cigarette smoke, but one group was given a diet rich in vitamin A. Among those rats receiving the vitamin A-rich foods, emphysema was effectively reduced.
Baybutt believes vitamin A's protective effects may help explain why some smokers do not develop emphysema. "There are a lot of people who live to be 90 years old and are smokers," he said. "Why? Probably because of their diet…The implications are that those who start smoking at an early age are more likely to become vitamin A deficient and develop complications associated with cancer and emphysema. And if they have a poor diet, forget it." If you or someone you love smokes, or if your work necessitates exposure to second hand smoke, protect yourself by making sure at least one of the World's Healthiest Foods that are rich in vitamin A, such as sweet potatoes, is a daily part of your healthy way of eating. (October 21, 2004)
