Refined grains
Refined grains have been significantly modified from their natural composition, in contrast to
, either through grinding or selective sifting.Overview
A refined grain is defined as having undergone a process that removes the bran, germ and
After refinement of grains became prevalent in the early 20th-century, nutritional deficiencies (
Refining grain includes mixing, bleaching, and brominating; additionally, folate, thiamin, riboflavin, niacin, and iron are added back in to nutritionally enrich the product.[6] Enriched grains are refined grains that have been fortified with additional nutrients. Whole grains contain more dietary fiber than refined grains. After processing, fiber is not added back to enriched grains.[6] Enriched grains are nutritionally comparable to whole grains but only in regard to their added nutrients.[5] Whole grains contain higher amounts of minerals including chromium, magnesium, selenium, and zinc and vitamins such as Vitamin B6 and Vitamin E.[5][6] Whole grains also provide phytochemicals which enriched grains lack.[5]
In the case of
Research
The dietary guidance of many countries is to replace refined grains with whole grains.[9][10] The Dietary Guidelines for Americans (2020–2025) advises people to limit their intake of refined grains to be no more than half of total daily grain consumption.[11]
Cardiovascular disease
The American Medical Association have advised people to consume whole grains instead of refined grains to improve cardiovascular risk factors.[12]
A 2020 review of controlled trials that used the GRADE approach found that although whole grains have been shown to improve low-density lipoprotein and total cholesterol there is insufficient evidence to recommend "whole grains as opposed to refined grains for the prevention and treatment of CVD".[13]
Obesity
There is no strong scientific evidence associating refined grains with obesity.[14][15]
Nutrition
Wheat | Rice | |||||
---|---|---|---|---|---|---|
Whole | Refined | Enriched | Whole | Refined | Enriched | |
Food energy | 100% | 107% | 107% | 100% | 99% | 99% |
Carbohydrates | 100% | 105% | 105% | 100% | 104% | 104% |
Fiber | 100% | 22% | 22% | 100% | 37% | 37% |
Protein | 100% | 75% | 75% | 100% | 90% | 90% |
Thiamin (B1) | 100% | 27% | 176% | 100% | 17% | 144% |
Riboflavin (B2) | 100% | 19% | 230% | 100% | 53% | 53% |
Niacin (B3)
|
100% | 20% | 93% | 100% | 31% | 82% |
Pantothenic Acid (B5) | 100% | 43% | 43% | 100% | 68% | 68% |
Pyridoxine (B6) | 100% | 13% | 13% | 100% | 32% | 32% |
Folate (B9)
|
100% | 59% | 350% | 100% | 40% | 1155% |
Vitamin E | 100% | 5% | 5% | 100% | 18% | 18% |
Calcium | 100% | 44% | 44% | 100% | 100% | 100% |
Iron | 100% | 30% | 120% | 100% | 54% | 293% |
Magnesium | 100% | 16% | 16% | 100% | 17% | 17% |
Phosphorus | 100% | 31% | 31% | 100% | 35% | 35% |
Potassium | 100% | 26% | 26% | 100% | 52% | 52% |
Sodium | 100% | 40% | 40% | 100% | 71% | 71% |
Zinc | 100% | 24% | 24% | 100% | 29% | 29% |
Copper | 100% | 38% | 38% | 100% | 79% | 79% |
Manganese | 100% | 18% | 18% | 100% | 29% | 29% |
Selenium | 100% | 48% | 48% | 100% | 65% | 65% |
See also
References
- ISBN 978-0123918826
- ^ "Grains". myplate.gov. Retrieved 16 November 2022.
- ^ "Whole Grains, Refined Grains, and Dietary Fiber". heart.org. Retrieved 16 November 2022.
- PMID 34741520.)
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- ^ ISBN 9781284122305
- S2CID 58561104.
- PMID 24398274.
- PMID 32728750.)
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: CS1 maint: multiple names: authors list (link - PMID 32728749.
- ^ "Dietary Guidelines for Americans (2020-2025)". dietaryguidelines.gov. Retrieved 16 November 2022.
- S2CID 240422142.
- S2CID 221746754.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - PMID 22300595.
- PMID 33062912.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - ^ USDA Standard Reference 17 Food Nutrient Database