Whole grain

Key takeaways

Whole grain belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Whole grain to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Whole grain from memory before moving on to harder problems.

Reference excerpt

A whole grain is a grain of any cereal or pseudocereal that contains the endosperm, germ, and bran, in contrast to refined grains, which retain only the endosperm. As part of a general healthy diet, consumption of whole grains is associated with lower risk of several diseases. Whole grains are a source of carbohydrates, multiple nutrients and dietary fiber.

Varieties Whole grain sources include: Cereals

Wheat (spelt, emmer, farro, einkorn, Kamut, durum) Rice (Black rice, brown, red, and other colored rice varieties) Barley (hulled and dehulled but not pearl) Maize or corn Rye Oats (including hull-less or naked oats)

Minor cereals

Millets Sorghum Teff Triticale Canary grass Job's tears Fonio, black fonio, Asian millet Wild rice Pseudocereals

Amaranth Buckwheat, Tartary buckwheat Quinoa

Health effects Because whole grain foods are more healthful than the equivalent with refined flours, organizations such as the Danish Whole Grain Partnership promote the consumption of whole grain foods as a public health measure.

Nutrition Whole grains are a source of multiple nutrients and dietary fiber, recommended for children and adults in several daily servings containing a variety of foods that meet whole grain-rich criteria. As components of breakfast cereals, whole grains are associated with improved micronutrient intake and lower risk of several diseases. Their effects on gastrointestinal health, risk of obesity and cognition need further evaluation. Cereal proteins have low quality, due to deficiencies in essential amino acids, mainly lysine. Supplementation of cereals with proteins from other food sources (mainly legumes) is commonly used to compensate for this deficiency, since the limitation of a single essential amino acid causes the others to break down and become excreted, which is especially important during the period of growth. In contrast, the proteins of the pseudocereals have a high nutritional value, close to those of casein (the main protein in milk). Quinoa and amaranth are the most nutritious grains due to their high content and quality of proteins, with high levels of lysine and other essential amino acids.

Disease risk Manufacturers of foods containing whole grains in specified amounts are allowed a health claim for marketing purposes in the United States, stating: "low fat diets rich in fiber-containing grain products, fruits, and vegetables may reduce the risk of some types of cancer, a disease associated with many factors" and "diets low in saturated fat and cholesterol and rich in fruits, vegetables, and grain products that contain some types of dietary fiber, particularly soluble fiber, may reduce the risk of heart disease, a disease associated with many factors". The scientific opinion of the European Food Safety Authority related to health claims on gut health or bowel function, weight control, blood glucose and insulin levels, weight management, blood cholesterol, satiety, glycemic index, digestive function and cardiovascular health is "that the food constituent, whole grain, (...) is not sufficiently characterised in relation to the claimed health effects" and "that a cause and effect relationship cannot be established between the consumption of whole grain and the claimed effects considered in this opinion." By supplying high dietary fiber content, as part of a general healthy diet, consumption of whole grains may lower risk of several diseases, including coronary heart disease, stroke and cancer, with lower all-cause mortality. Regular whole-grain consumption may lower elevated LDL and triglyceride levels, which are risk factors for cardiovascular diseases. Whole grain consumption is associated with a lower risk of type 2 diabetes. In 2012, Health Canada stated that "the evidence to date from clinical trials and prospective cohort studies was not sufficient to support a whole grains and coronary heart disease risk reduction claim in Canada". A 2017 review of clinical trials found insufficient evidence for a relationship between whole grain consumption and lowered risk of cardiovascular diseases. The American Institute for Cancer Research and World Cancer Research Fund International have stated that there is strong evidence that whole grains decrease risk of colorectal cancer.

Gluten concerns In genetically susceptible people, gluten (proteins found in wheat, barley, rye, oat, and related species and hybrids) can trigger coeliac disease. Coeliac disease affects about 1% of the general population in developed countries. There is evidence that most cases remain undiagnosed and untreated. The only known effective treatment is a strict lifelong gluten-free diet. Minor cereals and pseudocereals may be a reasonable alternative to replace gluten-containing cereals for people who need to follow a gluten-free diet. While coeliac disease is caused by a reaction to wheat proteins, it is not the same as a wheat allergy. Other diseases triggered by eating gluten are non-coeliac gluten sensitivity, (estimated to affect 0.5% to 13% of the general population), gluten ataxia and dermatitis herpetiformis.

Regulations In the United States wholegrain products can be identified by the ingredients list. "Wheat flour" (as opposed to "wholegrain wheat flour" or "whole-wheat flour") as the first ingredient is not a clear indicator of the product's wholegrain content. If two ingredients are listed as grain products but only the second is listed as wholegrain, the entire product may contain between 1% and 49% wholegrain. Many breads are colored brown (often with molasses or caramel color) and made to look like wholegrain when they are not. In addition, some food manufacturers make foods with wholegrain ingredients, but, because wholegrain ingredients are not the dominant ingredient, they are not wholegrain products. Contrary to popular belief, wholegrains are not indicative of fiber. The amount of fiber varies from grain to grain, and some products may have things like bran, peas, or other foods added to boost the fiber content. According to the American Association of Cereal Chemists definition, "Whole grains shall consist of the intact, ground, cracked or flaked caryopsis, whose principal anatomical components - the starchy endosperm, germ and bran - are present in the same relative proportions as they exist in the intact caryopsis."

US standards of identity The following names indicate whole-grain products, in accordance with the US federal government:

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Whole grain

Start with the simplest possible case. Write down what Whole grain claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Whole grain before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Whole grain ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Whole grain

In research: Whole grain appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Whole grain in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Whole grain is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cereals, Whole grain, so understanding it makes those chapters shorter.
In everyday life: Look for Whole grain outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Whole grain in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Whole grain means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Whole grain out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Whole grain in simple terms?

A whole grain is a grain of any cereal or pseudocereal that contains the endosperm, germ, and bran, in contrast to refined grains, which retain only the endosperm. As part of a general healthy diet, consumption of whole grains is associated with lower risk of several diseases.

Why does Whole grain matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Whole grain?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Whole grain.