Golden Rice: Fighting ‘hidden hunger’

By Aileen Alcos Garcia

October 30, 2019

In a bid to combat “hidden hunger,” an international research agency is developing rice varieties with higher levels of iron, zinc and beta-carotene.

Healthier rice varieties have the potential to reach many people because rice is already widely grown and eaten, Dr. Russell Reinke, Healthier Rice Program Lead from the International Rice Research Institute (IRRI), told the Cornell Alliance for Science Global Leadership Fellows.

“Even a small increase in the micronutrient content of rice grains could have a significant impact on human health,” he added.

Rice is the dominant cereal crop in most Asian countries and the staple food for more than half of humanity. Many people rely heavily on rice for most of their energy needs because they cannot afford or access a full range of nutritious options such as fruits, vegetables, and food from animal sources such as meat, milk, and eggs.

As a result, deficiencies in micronutrients such as iron, zinc, and vitamin A are more prevalent in rice-consuming countries. Micronutrient malnutrition, popularly known as hidden hunger, is a serious public health problem affecting two billion people globally. It can result in more frequent and severe illness and complications during pregnancy, childbirth, infancy, and childhood. The cost of these deficiencies in terms of lives and quality of life lost is enormous, and women and children are most at risk.

Approaches to address hidden hunger, such as the promotion of balanced diets, breastfeeding, capsule supplementation and food fortification, have been proven effective. However, target populations are oftentimes missed with these interventions, especially those in hard to reach areas.

Reinke reported that vitamin A deficiency (VAD) affects 190 million children and 19 million pregnant and lactating women worldwide. According to the World Health Organization, over 165 million children globally are stunted, and zinc deficiency is the major cause of stunting. Two billion people worldwide have anemia, about half of which is due to iron deficiency anemia (IDA).

IRRI, together with its national research partners, is developing rice varieties that have higher levels of iron, zinc, and beta-carotene to help people get more of these micronutrients through the rice they eat.

Golden Rice is one of the healthier rice varieties that has been in development for a long time. It is a genetically engineered rice that contains beta-carotene in the grain, which is converted into vitamin A inside the body as needed. Golden Rice is expected to be grown just like ordinary rice. Research indicates that one cup of Golden Rice can provide up to 50 percent of the daily requirement of an adult for vitamin A.

In an article published in the Journal of Agriculture and Food Chemistry in June 2019, Dr. B.P. Mallikarjuna Swamy and the Healthier Rice team at IRRI and the Philippine Rice Research Institute (PhilRice), presented findings showing the nutrient content of Golden Rice and its potential nutritional impact.

Swamy and the Healthier Rice team examined the content of key nutritional components, proximates and minerals in the paddy rice, straw, and bran of Golden Rice and compared these with a control sample of PSBRc82, the parent variety from the Philippines. All components of Golden Rice, including its protein content, were found to be substantially equivalent to ordinary rice, with one exception: Golden Rice grains contain up to 7.31 ppm of beta-carotene, while ordinary rice had amounts too insignificant to measure.

“The results of the compositional analysis show that Golden Rice is as safe as ordinary rice, but with the added benefit of beta-carotene content,” Swamy said. “Rice has a simple and easily digestible food matrix, which allows for a high bioavailability and bioconversion of beta-carotene to vitamin A.”

This only means that the beta-carotene in Golden Rice can easily be converted by the human body into the amount of vitamin A that it needs. Previous studies show that the bioconversion efficiency of Golden Rice compares favorably to other beta-carotene biofortified crops, like cassava and yellow maize. Compared to spinach, a vegetable widely recognized as a rich source of vitamin A, the beta-carotene in Golden Rice is converted by the body into vitamin A about 5-times more efficiently.

For rice-eating countries like the Philippines and Bangladesh — where Golden Rice is currently undergoing regulatory review — this could help reduce VAD in vulnerable populations. Just 100 grams of uncooked Golden Rice could supply up to 57 percent of the estimated average requirement (EAR) for vitamin A of pre-school children and from 38-47 percent of the EAR for pregnant and lactating women.

The data was gathered from the multi-location field trials held in four different locations in the Philippines during the 2015-2016 planting seasons. This formed part of the biosafety dossier submitted for regulatory applications to the Department of Agriculture-Bureau of Plant Industry in the Philippines, Food Standards Australia New Zealand, Health Canada and the United States Food and Drug Administration. To date, Golden Rice has received positive safety assessments from the latter three agencies and is still undergoing regulatory review in the Philippines and Bangladesh.

“As developers of Golden Rice, it is our responsibility to demonstrate its safety and benefits to the public,” Reinke said. “The next step is to evaluate its efficacy in providing 30-50 percent of the EAR for Vitamin A for micronutrient deficient women and children, but this will only take place once all regulatory approvals have been received.”

Reinke added that work on increasing the iron and zinc content of rice has likewise started with the ultimate aim of combining this with Golden Rice to produce rice that has all three micronutrients.

Rice researcher Dr. Russell Reinke in the field.

Rice will remain an important food staple for billions of people. To help ensure that rice can contribute to the healthy diets of rice consumers worldwide, IRRI and its research partners are committed to delivering healthier rice varieties that are safe, nutritious, and accessible in a sustainable manner.

Communication and advocacy play a major role in this important work in ensuring that the institutions involved are well-equipped in managing public perceptions and making decisions based on evidence. This is an area where the Cornell Alliance for Science Fellows are positioned to support the mission of improving the health and nutrition of populations by promoting access to this important innovation as it moves from development to deployment.

Aileen Alcos Garcia is a 2019 Global Leadership Fellow from the Philippines.