Starch represents the plant’s energy storage organs. It forms from glucose and can be found in fruit, seeds, rootstocks and tubercles especially in mature plants that produce it in order to germinate. (2)
Starch is a complex carbohydrate that is broken down to glucose once in the body. Follow the above scheme that highlights the main types of carbohydrates which will further be of great help in consolidating your nutritional education:
Over the course of time, starch foods have been considered both angels and demons. Some of the approaches in nutrition argued against carbohydrate consumption (starch included), whereas others were in favor.
In order to better understand and at the same time asses why starch is such a disputed topic, it’s important to pinpoint the food sources that contain starch and differentiate between them:
| Resistant starch type: | Found in: | Resistance minimized by: |
| RS 1 | Whole or partly milled grains, seeds, peanuts, beans and legumes | Milling, chewing |
| RS 2 | Raw potatoes, green bananas, some legumes, a type of corn | Food processing and cooking |
| RS 3 | Cooked and cooled potatoes, bread, cornflakes, food products with repeated moist heat treatment | Processing conditions |
| RS 4 | Foods in which modified starches have
been used (for example, breads, cakes) |
Less susceptible to digestibility in vitro |
Source: (4)
At opposite poles are genetically modified starches (number 4 in the above table) and resistant starch (numbers 1-3). Modified starch is obtained and chemically altered in order to increase its digestibility, whereas resistant starch refers to a part of starch and starch based products that are not digestible in the digestive tract. (3)
Given that more and more ailments are now considered to be rooted in the diet one adopts, the consumption of bad starch (genetically modified included) has been associated with a poor heath while resistant starch with a significant decrease of illnesses.
Some of the benefits of resistant starch are:
| Resistant starch effect: | Ailments that can be alleviated: |
| Improve glycaemic and insulinaemic responses | Diabetes, impaired glucose and insulin responses, the metabolic syndrome |
| Improved bowel health | Colorectal cancer, ulcerative colitis, inflammatory bowel disease, diverticulitis, constipation |
| Improved blood lipid profile
|
Cardiovascular disease, lipid metabolism, the metabolic syndrome |
| Prebiotic and culture protagonist | Colonic health |
| Increased satiety and reduced energy intake | Obesity |
| Increased micronutrient absorption | Enhanced mineral absorption, osteoporosis |
| Adjunct to oral rehydration therapies | Treatment of cholera, chronic diarrhoea |
| Synergistic interactions with other dietary components, e.g. dietary fibres, proteins, lipids | Improved metabolic control and enhanced bowel health |
| Thermogenesis | Obesity, diabetes |
Source: (3)
Therefore, in regard to starch it is paramount to first evaluate the type of food and the cooking method used to obtain it. For instance, whole rice is a great source of resistant starch when boiled. If however, it is consumed as rice bubbles, its resistance to digestibility is greatly reduced due to the preparation technique.
Great quantities of starch are found in (per 100 grams of product):
Source: (1)
“All large populations of trim, healthy people, throughout verifiable human history, have obtained the bulk of their calories from starch.” (The Starch Solution – John McDougall)
One of the most fervent advocates of starch consumption (the way it is naturally found) is Dr. John McDougall. His approach refers to the fact that throughout time the peoples diets have consisted mainly of starches and his theory is based on archeological research that has confirmed that the main ingredients were indeed: potatoes, sweet potatoes, wheat, cassava, quinoa, corn and so on.
For more information on the subject find below one of his conferences:
All in all, starch itself is not harmful but the way we choose to integrate it in our daily menu, therefore don’t jump to conclusions when it comes to starches and opt for natural foods and ingredients and simple cooking techniques (boiling, steaming, no oil baking).
