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"Zipcode lottery" of nutrient intake from crops revealed in new study

The amount of nutrients people get from the crops that they eat is a type of 'postcode lottery', according to new research that has analyzed thousands of cereal grains and soils as part of a project to tackle hidden hunger.

A global team led by the University of Nottingham working on the GeoNutrition project have discovered more about the relation between soils, crops and micronutrient deficiencies among people living there. Their findings have been published today in the journal Nature.


The team analyzed the grain of more than 3000 cereal crop samples from farmers' fields. They found that the amount of the dietary micronutrients calcium, iron, selenium, and zinc in the cereal grain varied substantially with location, with some areas showing much lower levels of micronutrients than others. Some cereal types, such as millets, are more nutritious than others, such as maize (corn). However, whether deficiencies are likely in an area also depends on its soils and landscapes.

Micronutrients include the vitamins and minerals which the body requires from the diet in small quantities, for a range of functions. Micronutrient deficiencies, also known as "hidden hunger", are common globally, affecting more than half of children younger than 5 years of age, especially where access to sufficient food from plant and animal sources that are rich in micronutrients is limited for socioeconomic reasons. Micronutrient deficiencies pose a serious risk to human health, including the growth and cognitive development of children and susceptibility to infectious and non-communicable diseases.

This research shows that location is intrinsically linked to the nutritional quality of diets. Getting enough micronutrients is a type of "zipcode lottery" with nutritional value varying by location. This will particularly affect rural households who consume locally sourced food, including many smallholder farming communities where location may even be the largest influencing factor in determining the dietary intake of micronutrients.

Nutritional surveillance on the quality of soil is an important part of wider public health policies to address micronutrient deficiencies.


ORGANIC VS. NON-ORGANIC

The word "organic" refers to the way farmers grow and process agricultural products, such as fruits, vegetables, grains, dairy products and meat. Organic farming practices are designed to meet the following goals:

  • Enhance soil and water quality

  • Reduce pollution

  • Provide safe, healthy livestock habitats

  • Enable natural livestock behavior

  • Promote a self-sustaining cycle of resources on a farm

Materials or practices not permitted in organic farming include:

  • Synthetic fertilizers to add nutrients to the soil

  • Sewage sludge as fertilizer

  • Most synthetic pesticides for pest control

  • Irradiation to preserve food or to eliminate disease or pests

  • Genetic engineering, used to improve disease or pest resistance or to improve crop yields

  • Antibiotics or growth hormones for livestock


Organic food: Is it safer or more nutritious?

There is a growing body of evidence that shows some potential health benefits of organic foods when compared with conventionally grown foods. While these studies have shown differences in the food, there is limited information to draw conclusions about how these differences translate into overall health benefits.


Potential benefits include the following:

  • Nutrients. Studies have shown small to moderate increases in some nutrients in organic produce. The best evidence of a significant increase is in certain types of flavonoids, which have antioxidant properties.


  • Omega-3 fatty acids. The feeding requirements for organic livestock farming, such as the primary use of grass and alfalfa for cattle, result in generally higher levels of omega-3 fatty acids, a kind of fat that is more heart healthy than other fats. These higher omega-3 fatty acids are found in organic meats, dairy and eggs.


  • Toxic metal. Cadmium is a toxic chemical naturally found in soils and absorbed by plants. Studies have shown significantly lower cadmium levels in organic grains, but not fruits and vegetables, when compared with conventionally grown crops. The lower cadmium levels in organic grains may be related to the ban on synthetic fertilizers in organic farming.


  • Pesticide residue. Compared with conventionally grown produce, organically grown produce has lower detectable levels of pesticide residue. Organic produce may have residue because of pesticides approved for organic farming or because of airborne pesticides from conventional farms. The difference in health outcomes is unclear because of safety regulations for maximum levels of residue allowed on conventional produce.


  • Bacteria. Meats produced conventionally may have a higher occurrence of bacteria resistant to antibiotic treatment. The overall risk of bacterial contamination of organic foods is the same as conventional foods.

Food safety tips

Whether you go totally organic or opt to mix conventional and organic foods, be sure to keep these tips in mind:


  • Select a variety of foods from a variety of sources. This will give you a better mix of nutrients and reduce your likelihood of exposure to a single pesticide


  • Buy fruits and vegetables in season when possible. To get the freshest produce, ask your grocer what is in season or buy food from your local farmers market.


  • Read food labels carefully. Just because a product says it's organic or contains organic ingredients doesn't necessarily mean it's a healthier alternative. Some organic products may still be high in sugar, salt, fat or calories.


  • Wash and scrub fresh fruits and vegetables thoroughly under running water. Washing helps remove dirt, bacteria and traces of chemicals from the surface of fruits and vegetables, but not all pesticide residues can be removed by washing. Discarding outer leaves of leafy vegetables can reduce contaminants. Peeling fruits and vegetables can remove contaminants but may also reduce nutrients.


References:

  1. D. Gashu, P. C. Nalivata, T. Amede, E. L. Ander, E. H. Bailey, L. Botoman, C. Chagumaira, S. Gameda, S. M. Haefele, K. Hailu, E. J. M. Joy, A. A. Kalimbira, D. B. Kumssa, R. M. Lark, I. S. Ligowe, S. P. McGrath, A. E. Milne, A. W. Mossa, M. Munthali, E. K. Towett, M. G. Walsh, L. Wilson, S. D. Young, M. R. Broadley. The nutritional quality of cereals varies geospatially in Ethiopia and Malawi. Nature, 2021; DOI: 10.1038/s41586-021-03559-3

  2. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/organic-food/art-20043880



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