A look at improved rice nutrition
Rice is the staple food for more than half of the world’s most undernourished. Rice grains that are nutritionally and safely enhanced for increased vitamins, minerals, essential amino acids or secondary metabolites hold the promise of improving the nourishment status of the impoverished and marginalized sectors of the population.
Two billion people suffer from what is known as “hidden hunger,” or micronutrient malnutrition. More than half of the world’s population (including many of those living in poverty) rely heavily on rice for most or their entire calorie needs because they cannot afford, or do not have access to, a full range of nutritious foods such as fruits, vegetables, meat, and dairy. As a result, lack of iron, zinc, and vitamin A has become prevalent micronutrient deficiencies in rice-consuming countries. The cost of these deficiencies in terms of lives and quality of life lost is enormous, and women, children, and the elderly are most at risk.
Additionally, the perceived high glycemic index (GI) of rice is becoming a growing concern, with some studies linking long-term consumption with an increased risk of developing type II diabetes. Type II diabetes is a chronic disease that can cause many medical complications, and is affecting more and more people throughout the world, especially in Asia. nt current strategies to reduce micronutrient deficiencies.
Healthier rice varieties have the potential to reach many people because rice is already widely grown and eaten. IRRI is developing rice varieties that have enriched micronutrient content, while also doing research into novel rice varieties and different rice types that can be part of a healthy low-GI diet.
HIZR (High Iron & Zinc Rice)
Most of the iron content of rice is accumulated in the external bran that is removed after polishing (in white rice). IRRI is researching ways to increase the iron concentration in the endosperm, or the consumed part of the rice, in order to develop iron-enriched rice varieties.
Through the extensive repository of germplasm in the IRRI Genebank, IRRI in collaboration with partners around the world are cross-breeding rice with naturally higher levels of zinc to develop new, high-zinc, high-yielding consumer rice varieties.
The creation of Golden Rice, a rice variant that contains provitamin A or beta carotene, was a major breakthrough in biofortification. IRRI continues to develop Golden Rice through breeding of Asian rice varieties, field tests, safety and efficacy assessments, and sustainable delivery programs.
Low Glycemic Index rice
Rice in general had been categorized as a high glycemic index (GI) food, but IRRI research has shown that the GI content of rice varies from one type of rice to another. Additionally, IRRI and its partners have been able to identify the key gene that determines the GI of rice, offering rice breeders the opportunity to develop rice varieties with different GI levels to meet consumer needs.
Biofortified rice varieties in the planning stages
- Pyramided lines
- High Folate rice
- High Lysine rice
- High Leucine
- Non-GM High iron rice
Reducing iron deficiency anemia
The World Health Organization (WHO) estimates that 2 billion people—or about 30% of the world’s population—are anemic, many due to iron deficiency. The availability of IRRI’s iron-rich rice, especially in developing countries, has the potential to reduce that number significantly, improving not just the health of the individual, but also influencing the overall productivity of the population (studies from WHO suggest that treatment of iron deficiency anemia can boost national productivity levels by up to 20%).
World’s first zinc-enriched rice launched in Bangladesh
Zinc mineral intake is essential for survival, and zinc deficiency has serious consequences for health, particularly during childhood when zinc requirements are highest. With parental germplasm developed at IRRI, the Bangladesh Rice Research Institute (BRRI) was able to develop the world’s first zinc-rich rice variety dhan 62, containing 20 to 22 parts per million (ppm) of zinc, while the average zinc content of rice is 14 to 16 ppm. The variety was released in Bangladesh in 2013 (see Rice Today, Vol. 12 No. 4).
A solution to Vitamin A deficiency
The World Health Organization (WHO) estimates that 190 million preschool children and 19 million pregnant women are vitamin A deficient globally. Biofortified with beta-carotene identical to those found in many types of vegetables and fruit, Golden Rice can supply from 30 to 50 percent of the average vitamin A requirement of preschool-age children and pregnant or lactating mothers, and potentially prevent 1.3–2.5 million of the nearly 8 million late-infancy and preschool-age child deaths annually in developing countries.
The key to the glycemic index of rice
A major public health challenge for almost every country across the globe, the number of people living with diabetes worldwide is expected to rise to over 592 million by 2035, with the pandemic cutting across all socio-economic, gender, and age groups. By analyzing 235 types of rice from around the world, IRRI in collaboration with CSIRO in Australia found that the more amylose (a type of starch in rice) is in a particular rice variety, the lower the GI (and vice versa). This discovery has the potential to significantly impact the diabetes pandemic, as it can help rice consumers make informed choices on the types of rice to eat, as well as lead to the development of new and novel varieties of low GI rice.