Biofortified and bioavailable: The gold standard for plant-based diets

Abstract

Much of the world's population relies on a few staple foods (rice, maize, wheat, and cassava) that are poor sources of essential nutrients. Biofortification, the process of enriching the nutrient content of crops as they grow, provides a sustainable solution to malnutrition worldwide, because other methods, such as diversifying people's diets or providing dietary supplements, have proved impractical, especially in developing countries (1). One of the first biofortified crops was golden rice, which was engineered to produce beta-carotene or provitamin A in the edible portion of the grain (2). Since then, there have been similar successes with other crops, giving us a variety of carotenoid-enriched foods (1) as well as crops enriched with other micronutrients such as vitamin E (3) and folate (4). However, in each of these cases, assumptions about whether the nutrients are bioavailable—i.e., whether the nutrients can be readily absorbed by humans—remain untested. In a recent issue of PNAS, Morris et al. (5), using feeding studies with both mice and humans, report that carrots genetically engineered to accumulate twice as much calcium as control carrots are indeed a good source of this essential nutrient, resulting in a ≈50% increase in calcium absorption.