After decades of development, the Philippines became the first official announcement on July 21 this year Approval of commercial communication The so-called golden rice. This is a genetically modified rice strain that can produce β-carotene in its grains. This is the same compound that made carrots so famous and a great source of vitamin A.
I am full Vitamin A It is important not only for children and newborns, but also for pregnant and breastfeeding women.Currently, vitamin A deficiency (VAD) is The main cause of preventable blindness in children And an important cause of infant death. Although VAD is not the only major form of global malnutrition, biofortification measures like golden rice can significantly improve the lives of millions of people around the world by reducing the impact of VAD.
This raises the question of how effective measures such as golden rice are, and whether biofortification of staple foods will become more common in the future, including in the United States. fortification Food has become commonplace.
Let the plants do our bid
The domestication of plants is a continuous process, started by humans thousands of years ago Early farmers Start selecting and growing specific plants with desired characteristics. After many generations of plants, this will gradually produce many domesticated crops that we are familiar with today. This manual selection process increases the size of fruits and grains, makes crops easier to process and consume, and increases yields.
The 20th century witnessed the rise of intensive agriculture, which led to the so-called “green revolution” between the 1940s and 1970s, during which time agriculture around the world significantly increased production through technology: artificial fertilizers, improved irrigation, and improved The harvest method is more concentrated, but it is also a more concentrated artificial selection of plants.
pass Mutation breeding – Also known as mutagenesis or mutation breeding, and mutagenesis – Plant seeds are exposed to chemical substances, radiation or enzymes to produce genetic mutants. This introduces random changes to the genome of the plant cell, which may lead to ideal changes that can be selected.
or not.In fact, this is not much different from what happens naturally, it’s just much faster, much faster, and unfortunately, the same problem arises with unwelcome mutations, which may Crippled or killed Affected plants. Although this makes it a slow and laborious process, there is a reason for the mutagenicity of the thousands of fruits and vegetables we buy in supermarkets today.
Genetic modification can be contrasted with genetic engineering (GE), in which the genome of a plant is directly edited to achieve the desired changes. The benefits of genetic engineering are obvious: changes occur immediately, avoiding unwanted mutations.
In addition, in transgenic plants, it is possible to introduce genetic abilities that are foreign to the plant, such as the production of β-carotene in its grains. Even with mutagenized transgenic plants, such major changes are unlikely to happen spontaneously.In the current version of Golden Rice (GR2), the CrtI gene comes from Pantoea pineapple And phytoene synthase gene (Psy) from corn (corn) To complete the β-carotene pathway which is incomplete for rice grains.
Provide reasons for β-carotene in rice grains
Carotene is Generally considered Become an important part of the photosynthesis capacity of plants. This explains why β-carotene is a common ingredient in leafy green vegetables such as kale, spinach and broccoli, as well as pumpkin and carrots. Unfortunately, these green leafy vegetables or animal sources of vitamin A are not easily available in many parts of the world or cannot be bought if they are available.
As pointed out Said Akhtar et al.There are three ways to solve VAD: supplementation, fortification, and dietary diversification. Vitamin A supplements are only effective to a certain extent, because it relies on government organizations to provide regular supplements for everyone in need. When a person has less body fat, the efficiency of vitamin A supplementation is also reduced because it is fat-soluble. Similarly, fortification requires someone to add vitamin A (or β-carotene) to food, which assumes that government regulations on food fortification will not be circumvented, such as Akhtar et al. It is found to be very common in some areas.
Akhtar et al. The conclusion is that a diversified, multi-pronged approach is most likely to be effective here, because the weakness of one approach can mask the weakness of another approach.
Since golden rice does not require anything other than the usual planting and harvesting of rice, it will not add extra burden, but only raises the question of how effective it is. That is, how much vitamin A is converted from β-carotene in rice grains to people who consume a certain amount of golden rice?
A study in 2019 Swami et al. It was found that in the analysis of golden rice and ordinary rice grown in the Philippines from 2015 to 2016, the only significant difference was the presence of β-carotene and other provitamin A CarotenoidsBased on the existing beta-carotene levels, they calculated that 100 grams of raw golden rice can provide 30-40% of the recommended daily intake (RDI) of vitamin A for children and 11-13% for adult women. In any case, this is not a complete solution, but it helps.
nobody is perfect
Perhaps the most ironic aspect of malnutrition is that simply living in a country where (fortified) foods and supplements are readily available does not guarantee that a person will not be particularly deficient in micronutrients.Lack of vitamin C leads to scurvy Recovery in the U.S. (Dabag et al.), and France (Chalouhi et al.), and In Australia. Overcooking food and eating a lot of processed fast food are common factors here.
This involves the psychological reasons behind malnutrition, people Willingly refuse Eat a diet that contains the nutrients they need to consume to stay healthy. Who doesn’t know the image of children who don’t want to eat vegetables, only to be told by their parents that poor children in developing countries will seize the opportunity to eat their meals?
However, when the main problem in developing countries is the lack of a diversified diet to provide all the nutrients needed for healthy development, how to solve the problem of malnutrition in developed countries? The fight against malnutrition does seem to have many aspects, and multiple solutions are needed for this.
The first thing that should be pointed out here is that apart from the increase in carbohydrates, there is no evidence that the nutritional value of vegetables has declined, which can be attributed to the dilution effect caused by the increase in yield.this is Robin J. Marles in detail In the 2016 literature review article. Essentially, if people eat vegetables and fruits and protein sources, then developed countries should not have nutritional deficiencies.
Simple and difficult questions
In tackling malnutrition in developing countries, it is clear that biofortification measures such as golden rice can help reduce health problems caused by lack of micronutrients. The effort required is also relatively low.With Canada, Australia, New Zealand and now The U.S. has announced Golden rice that is safe to eat, it seems that at least this source of biofortified food may herald the end of malnutrition in developing countries.
Even so, unhealthy diet is still a global problem, according to Global burden of disease in 2017 (GDB) research, although many affected people can get the ingredients of this healthy diet at any time. For example, a major problem in developed countries is the large intake of sugar-sweetened beverages, as well as increased intake of processed meats, sodium, and red meat.
Ironically, addressing specific sources of malnutrition in developing countries is as simple as switching to crops such as golden rice or other biofortified foods. In richer countries, the problem is behavioral and it is not So obvious.