It is well known that cereal grain is an important component of a healthy diet. According to the United States Department of Agriculture Food Guide Pyramid, a balanced diet should include 6 to 11 servings per day of cereal products such as Breads, Rice, Pasta and Oatmeal compared with 2 to 3 servings of Dairy products and 2 to 3 servings of Meat or other protein products per day.

 Fibre and its importance in your diet

One of the major components of cereal grains such as oats that contributes to this health benefit is Fibre. Oats are one of the best food sources of Soluble Fibre which has been shown to contribute to improved Heart Health by maintaining a healthy blood cholesterol level.

The Quaker Oats Company in the United States has invested heavily in research so as to prove the benefits of Soluble Fibre as derived from Oats for human health. As a consequence of this research, the United States Food and Drug Administration issued approval for the first food specific health claim as follows:-

"Soluble fibre from oatmeal (or oat bran) as part of a low saturated fat and low cholesterol diet may reduce the risk of Heart Disease."

To qualify for this claim, foods containing oats must provide at least 0.75 grams of soluble fibre as beta-glucan per serving and products must be low in total fat, saturated fat, and cholesterol.

 What is Fibre?

Fibre is the carbohydrate portion of whole grain and some refined grain foods, as well as fruits and vegetables, that is not digested by human enzymes. Therefore fibre passes through the digestive tract instead of being broken down into the constituent components that are supplied as nutrients to the human body.
Adapted from Brody, Tom. (1994) Nutrients That Resist or Escape Digestion in Nutritional Biochemistry. Academic Press, New York.pp.107-123.

Dietary Fibre can be classified according to its solubility, namely Insoluble Fibre and Soluble Fibre which each have different health benefits.

 Insoluble Fibre

Insoluble fibre is fibre that is insoluble in alcohol. Insoluble Fibres in the diet increases the speed of passage of material through the large intestine and results in greater fecal bulk. By increasing the fecal bulk and reducing the length of time that material in the large intestine, the concentrations of toxins is lowered and the length of time they are present is reduced. This reduces the risk of cancers. Vegetables, wheat, Wheat Bran and most grain products are the major source of Insoluble Fibre.

 Soluble Fibre

Soluble fibre is fibre that is soluble in alcohol. Soluble Fibre can be digested by the small intestine and passed into the blood stream. This fibre is able to even out the rate of digestion of food in the small intestine and thus the rate of absorption of the various components of food into the blood stream. Oat products such as oatmeal and oat bran are extremely high sources of Insoluble Fibre. The main form of Soluble Fibre found in Oats and oat products is Beta Glucan.

 Reduction of Cholesterol Levels in the Blood

Cholesterol is used by the body to transport fats through the bloodstream to sites where they are used to sustain cell and body functions. However it is known that a high blood cholesterol level can lead to a risk of heart disease.

This is because high levels of a specific type of cholesterol, LDL Cholesterol, can cause the formation of plaque deposits on the walls of the coronary arteries. These deposits can reduce or block blood flow which may eventually lead to high blood pressure and heart attack.

Therefore LDL Cholesterol is described as "bad" cholesterol.

The other type of cholesterol, HDL Cholesterol, is only deposited in the Liver where it is used in the production of Bile. Bile is used in the digestion of fat when we eat. 50% of the Bile produced by the body exits the body as excreta and this is the only way that our bodies lose Cholesterol.

Therefore HDL Cholesterol is described as "beneficial" cholesterol.

It is believed (but not proven) that the Soluble Fibre in Oat products binds bile acids in the intestine and increases the percentage that is carried out of the body in our excreta. The liver then has to draw on blood serum cholesterol (LDL Cholesterol) to manufacture more bile thus reducing LDL Cholesterol levels in the blood.

 Control of Blood Sugars

Because of their viscosity, Soluble Fibres slow the release of food from the stomach and may decrease the rate of absorption of food sugars (glucose) in the small intestine. This effect may reduce the surge of plasma glucose and insulin that follows a meal and help control blood glucose levels.

A study in the United States tracked 35,000 women for 10 years to correlate the development of Type 2 diabetes with the dietary intake of whole grain cereals including oatmeal. The study showed that women who ate a diet rich in whole grain cereals and soluble fibre, especially oatmeal, had a much lower risk of developing Type 2 diabetes throughout the 10 year study period than those who ate fewer whole grain cereals and less soluble fibre.
Meyer KA, Kushi LH, Jacobs DR, Slavin J, Sellers TA & Folsom AR. Carbohydrates, Dietary Fibre and Incident Type 2 Diabetes in Older Women. American Journal of Clinical Nutrition 2000; 71:921-930.

 Sustained Energy Source

Instant Oatmeal has been described as being able to provide "slow burning sustained energy that will last longer into an active day".
Journal of Applied Physiology. A Moderate Glycemic Meal Before Endurance Exercise Can Enhance Performance. Journal of Applied Physiology, January 1998.

A research project described how women who ate Instant Oatmeal with 7 grams of dietary fibre were able to maintain a set speed on an exercise cycle for 15 minutes longer than after consuming a lower fibre cereal with 3 grams of dietary fibre. They were also able to cycle for 40 minutes longer after eating Instant Oatmeal than if they consumed water only.

The interpretation of this result is that the Soluble Fibre in Oatmeal, beta-glucan, extends the digestion and release of carbohydrates. As carbohydrates are an energy source, the body receives this energy over an extended period of time. This prevents a rapid depletion of the energy levels of the Oatmeal consumer.
The Quaker Oats Company, News Release 22nd January 1998

 Reduction in Hunger

Researchers at The University of Sydney have found that a breakfast of Oatmeal is more likely to make you feel less hungry than many other breakfast foods. The researchers developed a “satiety index” which is a guide to how much an individual’s appetite was satisfied, to determine what foods gave people a sense of fullness for longer periods.

They found that oatmeal was twice as filling as white bread; three times as filling as a donut; and almost five times as filling as a croissant.

A general trend of the study was that foods that are higher in fibre and protein and lower in fat were found to be more filling than other foods.
Holt SA, Miller JC, Petocz P and Farmakalidis E. A Satiety Index of Common Foods. European Journal of Clinical Nutrition 1995 49:675-690.

Also Researchers at the New York Obesity Research Center specifically tested Oatmeal against Corn Flakes. They identified that lunch intake was markedly reduced after eating a low Glycemic Oatmeal cereal compared to eating a high Glycemic Corn Flake cereal or a Water control.
New York Obesity Research Center. Lunch Meal Intake Following High and Low Glycemic Breakfast Cereals, St Luke’s/Roosevelt Hospital Center, New York U.S.A.