Sweet potatoes are a sure winner

 By BONEY WERA 

HEAVY dependence on sweet potatoes as a staple food in Papua New Guinea provides a unique opportunity to use the sweet potato as a tool to address certain forms of micronutrient malnutrition in the country. 

Studies done by nutritionists at the Centre for Science in the Public Interest (CSPI) in Washington DC, US, rank sweet potato number one in nutrition among all other common vegetables like potatoes, broccoli, cabbage, green peas, carrot, corn, cauliflower, tomato, etc. 

It is an excellent source of Vitamin A and β-carotene, a good source of Vitamin C, B6, manganese, potassium, iron, calcium and protein. 

Sweet potato is high in dietary fibre, naturally occurring sugars and complex carbohydrates (carbs). The antioxidant activity in sweet potato is almost three times higher than in the rest of the vegetable. 

In contrast, it has minimal fat content (especially saturated fat), sodium, cholesterol, added refined sugars and caffeine. 

Among root vegetables, sweet potatoes offer the lowest glycemic index rating, meaning that it is digested slowly, causing a gradual rise in blood sugar so you feel satisfied longer. 

Orange-fleshed sweet potatoes (OFSP) contain more than 50-fold more β-carotene, which is converted to Vitamin A after ingestion, than the yellow or white varieties commonly eaten. 

OFSP can be supplemented in the diets of the population who do not regularly have access to carrot and other similar foods that provides Vitamin A. 

Scientific studies have proven that eating OFSP reduces the prevalence of vitamin A deficiency in women and children. 

Vitamin A is critical for the development of good vision and necessary for normal organ formation and maintenance. 

Furthermore, purple-fleshed sweet potatoes (PFSP) have high contents of anthocyanin. Anthocyanins are powerful antioxidants that protect the body against degenerative diseases and have been epidemiologically associated with a reduced cancer risk. 

Studies have shown that the dominant purple colour in sweet potatoes results in an increased amount of anti-cancer components in human. 

So, it’s time to move sweet potatoes to the good carb list and let it linger in the heart of our everyday meal.It is estimated that about a third of the country’s population lives below the poverty line and more than 85% lives in rural areas where hidden poverty or micronutrient deficiency among women and children is high. Malnutrition is considered one of the most important underlying causes of poor health outcomes in PNG. 

Among the known micronutrients deficiency, iron, zinc and vitamin A deficiency are important public health problems in PNG. Furthermore, lifestyle diseases like high blood pressure, diabetes, cancers of the digestive tract, the liver and lungs as well as the ailments of the heart are on the rise. 

The consumption of unheal­thy and processed foods, coupled with mostly desk-bound jobs, has no doubt contributed to mortality rates in certain age groups. 

Going back to home grown organic foods would seem an easy alternative for many in our urban areas and the way forward for a new and healthier nation.

With sweet potato  thriving in PNG’s culture and farming system for centuries that provides almost 66% of the calorie intake, it can potentially be use as a remedial crop for combating certain forms of undernutrition and lifestyle diseases. 

Breeding and making available improved varieties of sweet potato to bulk of the rural population in PNG has enormous potential in alleviating micronutrient malnutrition. 

Thus, biofortification approach using sweet potato as a candidate crop may find its way useful in PNG’s context where there is a high dependence on sweet potato for calorie and nutrition. 

Biofortification is simply bree­ding staple crops using selective breeding to improve their nutritional status. Breeding sweet potato and other staple crops for high nutrition is one potential as well as sustainable strategy for addressing certain forms of undernutrition, apart from micronutrient supplementation, food diversification, and processed fortified foods. 

Biofortified sweet potatoes will provide not only carbohydrates when eating but other essential nutrients that come along with. The costs of these nutritional deficiencies in terms of lives lost, forgone economic growth, and poor quality of life are staggering. 

To make PNG a healthier com­munity, new technologies and multi-disciplinary approaches are needed to help address malnutrition problem. 

To address this issue, the current breeding programme in NARI based at Aiyura is focused on improving genetic potential and nutritional qualities of sweet potato. 

The programme is progressing well with the development of new varieties incorporating priority traits. 

The initial breeding cycles under have identified eight potentially new varieties out of 11,228 F1 seed progenies developed in 2005 and 2008.