Medal Earner of the week
The orange coloured sweet potato qualifies for a medal this week, being one of the healthiest foods available, common and readily available all the year round. Sweet potatoes are native to Central and South America and are one of the oldest vegetables known to man. They have been consumed since prehistoric times and evidence of their use as a food has been found in Peruvian caves dating back 10,000 years. They are a powerful anti-oxidant protecting us from damage to DNA and cellular structures. They are absolutely bursting with beta-carotene, from which our bodies can produce vitamin A. As little as 100 gms of sweet potatoes can provide more than 35% of all the vitamin A needs, in some cases as much as 90% of vitamin A needs from this one single food alone.
The flesh of sweet potatoes is not always orange coloured and the intensity of the colour directly relates to the beta-carotene content. It may be a beautiful rich purple colour but it is impossible to tell from the skin colour just how rich a purple it may be on the inside. The purple fleshed sweet potato has outstanding anti oxidant and anti inflammatory properties. Scientist believe this vegetable may be able to lower potential health risks from heavy metals and oxygen radicals as they pass through the digestive system.
To obtain the maximum benefit from the beta-carotene properties it helps to add a little fat, which increases the uptake of the vitamin. As little as a few grams is all that is needed, provided by adding a teaspoon of olive oil to the potato when mashing.
How to cook.
The best nutritional value is obtained from sweet potato by steaming or boiling. Compared to roasting, boiled sweet potato results in a lower GI value so has the best effect on controlling blood sugar levels. Steaming is also a good method of cooking since steaming for only a couple of minutes can deactivate the enzymes, which can break down the anthocyanins which have great health benefits as anti- oxidants and anti-inflammatory nutrients.
Sweet potatoes are quick to prepare. Boil and mash or cut into ½ inch slices and steam. Steaming for just 7 minutes brings out their great flavour and maximises their nutritional value.
It has now become general knowledge that all starches convert to sugars during digestion and raises the level of glucose in the blood. Control of the glucose level in the blood is essential to combat type 2 diabetes. So how can a starchy vegetable like sweet potato help to improve blood sugar levels? Even in persons already suffering from type 2 diabetes the dietary fibre in sweet potatoes are a definite plus as far as regulating blood sugar levels as the fibre content helps steady the pace of digestion. Also, recent research has shown that extract of sweet potatoes can increase the levels of a hormone produced by the body, which has an important effect in the metabolism of insulin. New research is being carried out to evaluate the sugar regulating benefits.
200 grams of Sweet potato;
Vitamin C 52%
Pantothenic acid 35%
Vitamin B6 34%
Vitamin B3 19%
Vitamin B1 18%
Vitamin B2 16%
How to Select:
Choose sweet potatoes that are firm, not bruised, and do not have cracks and soft spots. They should not be stored at cold temperatures as this alters the flavor so chose from the fresh food section not the chilled. They can be stored for more than a week if kept in a dark, dry cool well ventilated place. Do not keep in a plastic bag, a brown paper bag is fine but punch a few holes in the bag for ventilation. Organically grown sweet potatoes can be cooked and eaten whole including the skin. Sometimes, non organic varieties have had the skin treated with wax so should be peeled. This is easier to do after cooking. Once peeled or cut they should be cooked immediately to prevent oxidation, otherwise keep in a bowl completely covered in cold water until you are ready to cook them.
- Boiled and mashed as a healthy alternative to white potatoes.
- Cut into thin sticks and stir fried in a little oil.
- Baked sweet potatoes are delicious cold and make a great food to use for picnics or school lunches.