Vegetables lose their nutrients. Can this decline be reversed?


IIn 2004, Donald Davis and his fellow scientists at the University of Texas made an alarming discovery: 43 foods, most of them vegetables, showed marked declines in nutrients between the mid- to late-20th century.

According to this research, the calcium in green beans decreased from 65 to 37 mg. Vitamin A levels were reduced by about half in asparagus. Broccoli stems contain less iron.

Nutrient loss has continued since that study. Recent research has documented the decline in nutrient value in some staple crops due to rising atmospheric carbon dioxide (CO).2) levels; A 2018 study that tested rice found that high carbon dioxide2 Protein, iron and zinc levels decreased.

While the climate crisis has only exacerbated concerns about the nutritional value of crops, giving rise to a process called biofortification as a strategy to replenish lost nutrients or those that were not available in foods in the first place.

Biofortification includes multiple techniques. One involves genetically modifying the crop to increase its nutritional contents, allowing the rapid introduction of new traits. Another method, agricultural biofortification, uses nutrient-rich fertilizers or soil amendments to concentrate certain minerals in plants. Finally, selective breeding of plants can produce new varieties, although it may take a decade or more to produce a single variety.

Biofortification is an alternative to fortification, which has been part of the industrial diet in the United States since the 1920s, when the country began fortifying table salt with iodine to reduce conditions associated with mineral deficiencies, such as goiter. Biofortification places nutrients directly into the seeds, unlike fortification, which adds nutrients to the food once they grow. At the global level, international stakeholders, such as the World Health Organization (WHO) and the Consultative Group for International Agricultural Research (CGIAR), have considered the development of nutrient-enhanced biofortified crops as one of their main goals in achieving food security.

“Due to climate change, iron and zinc have decreased by 30-40% due to heavy rainfall, hail and physical damage,” explained Prateek Unyal, Program Head at the International Food Policy Research Institute (IFPRI).

HarvestPlus is an organization of the International Food Policy Research Institute (IFPRI), providing global leadership in biofortification evidence and technology. It currently works with governments in more than 30 countries, and its biofortified varieties have been grown by more than 10 million farmers worldwide, most of them in developing countries. By 2030, the organization estimates that one billion people will benefit from biofortified foods. “It’s about 20 years into a 40-year program,” said Jenny Walton, head of marketing and expansion for HarvestPlus. “We are trying to revolutionize basic food systems.”

While malnutrition demonstrates the urgent need to increase the nutrient density of crops globally, Benjamin Cohen, professor of environmental studies at Lafayette College, points to biofortification as a band-aid, not a solution to the problem.

“My concerns are with funders, depending on policymakers, choosing to invest in biofortification rather than supporting more durable smallholder farming models that can be more efficient and resilient than large-scale systems,” Cohen said. “Biofortification suggests a solution to a problem that would not exist without large-scale, capital-intensive agriculture. It is likely that those same agricultural operations will only be consolidated through biofortification.”

HarvestPlus believes that plant breeding is the most sustainable method of biofortification; It depends on the existing plant genes. The organization works exclusively with staple crops and develops them to contain greater amounts of vitamin A, iron and zinc, three micronutrients identified by the World Health Organization as being most deficient in diets globally. This approach means that in places like Pakistan, where the diet is rich in wheat, fortifying that grain could make a difference at a population level. HarvestPlus has already released 400 types of staple crops; None of them have been patented.

But there are other concerns about the loss of nutrients on a larger scale than what biofortification can replace.

Fruits and vegetables at the grocery store on Wednesday. Photograph: Martin Goodwin/The Guardian

“One limitation of biofortification is that it focuses on one or maybe two nutrients per plant, whereas nutrient decline tends to affect many plants,” said Davis, who led the original University of Texas study that showed diminished nutrient value in crops. nutrients at one time.

Then there’s the accessibility hurdle. Walton noted that there is not yet a steady supply of biofortified seeds. HarvestPlus also intends for its biofortified seeds to cost less than conventional seeds. But these lower costs are the result of government subsidies. For example, India has partnered with HarvestPlus to provide biofortified food to children, in a country with a high rate of malnutrition that stunts youth development.

The government partnership model could pay off in low- to middle-income countries, where malnutrition is common, and companies work directly with smallholder farmers who grow biofortified varieties, rather than at an industrial scale because seed supplies cannot yet reach that scale.

Cohen noted that although the need may be greater in less industrialized countries, these countries may have fewer mechanisms to resist policies emerging in better-resourced countries. They may have less regulation on genetically modified and biofortified crops, such as the controversial golden rice, which has been modified to produce beta-carotene and, as a result, vitamin A. While golden rice was bred to help mitigate vitamin A deficiency, Cohen wrote that this strategy embraces “technical fixes for problems that can be addressed in ways that are less dependent on mono-crop environments.” Essentially, if we grow diverse crops that contain the vitamins that a particular community lacks, it is possible to achieve the same nutritional result.

“Powerful countries have dictated the shape of other countries’ food systems, leaving them in a position of further malnutrition, and now because those countries do not have enough power to shape their policies in the global market, the same powerful countries can now step back and interfere in their own food systems,” he said.

In addition, the industrial farming system also favors chemical fortification, Peter said Kelly, CEO of Grow More, a charitable organization that invests in scalable early-stage agricultural innovations in developing countries. He stated, “There is not much interest in probiotic fortification for the American domestic market. Some American food companies support international work to improve nutrition. But this is not really necessary in our current era.” [US] Diet because it can be done by chemical fortification.

Kelly suggests combining biofortification with other seed changes — perhaps breeding them to be more drought-resistant — to further encourage stakeholders to invest in crops that are better suited to local growing conditions.

“All of our work revolves around climate change adaptation to some degree,” Kelly said. “CO2 levels can affect nutrient levels in plants; We have to do this plant breeding just to keep up. Promoting fruits, vegetables and beans is one approach, but if that is the only approach from a policy perspective, it is kind of ideal.

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