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What are refined carbohydrates? Are they really bad for your health?

Bárbara Therrie

Very present in the Brazilian table, white rice and sugar are part of a type of carbohydrate that has gained a reputation for not being very healthy. We are talking about refined carbohydrates, also known as simple carbohydrates. But are they really bad for your health? Before answering the question, let's first understand what they are and how they are produced.

"Refined carbohydrate is a generic term generally used to describe carbohydrates that have had most of their nutritional value removed during the manufacturing process," explains Viviane Sahade, nutritionist, doctor of medicine and health, and associate professor at the UFBA School of Nutrition. (Federal University of Bahia).

In its natural and complete form, grain seeds or grains consist of three parts: the bran, which has important nutrients such as fiber, minerals, and B vitamins; the germ, which contains carbohydrates, fats, proteins, and minerals; the endosperm, most of the starch.

When whole grain rice is refined into white grains, for example, the bran and germ are removed during processing, leaving only the starchy endosperm. "White rice is the most common example of refined carbohydrate. When brown rice is kept in its natural form, the whole grain is left intact," says Sahade.

The UFBA professor comments that when we consume whole grain or whole grain flour, the whole carbohydrate obtains all the fiber, proteins, vitamins, minerals, and nutritious fats that these foods have to offer. "In refined grains, with the removal of the bran and the germ, we lose the nutrients provided by the grain".

We can also mention refined sugar, which is an industrial extraction of natural sugar. Table sugar and high-fructose corn syrup are two examples of refined sugars. These refined sugar-based foods are very calorie-dense and high on glycemic content and are considered empty calories.

"Unfortunately, most carbohydrates in Western diets are highly processed, including bread, most cold cereals, and ready-to-eat sugar," says Andrea Pereira, a clinical nutrition physician in the department of oncology and hematology at Hospital Israelita Albert Einstein, and author from the book "Balance Diet - The best anticancer diet".

Refined carbohydrates are not very nutritious precisely because of the loss of fiber and micronutrients, in this case, vitamins and minerals, which occur with refining.

But are they bad for your health?

As always, the problem is excess. According to Renata Alves, nutritionist preceptor of the outpatient clinic of the Instituto Dante Pazzanese de Cardiologia, when consumed in excess, refined carbohydrates can cause health problems, such as obesity, metabolic changes such as insulin resistance, increased blood glucose, and triglycerides. "These changes, taken together, can increase the risk of developing cardiovascular diseases, such as heart attack, stroke, and thrombosis," she says.

The problem is that refined carbohydrates are digested and absorbed more quickly, as they are low in fiber. According to Andrea Pereira, a clinical nutrition physician, because they have a high glycemic content, they stimulate more the release of insulin, a hormone responsible for controlling blood glucose. "With that, there is less satiety and the person can get hungry faster".

"However, when refined carbohydrate is combined with a protein (milk and dairy products, meat, eggs, beans, lentils, chickpeas, and soy), healthy fats (nuts, olive oil, avocado) or fiber (oats, seeds ), the speed of digestion and absorption is slower than when consumed alone, reducing the impact of postprandial blood glucose and insulin (meal). This composition promotes a lower glycemic load", comments nutritionist Alves.

This type of carbohydrate can be part of the diet, as long as it is inadequate amounts for each individual's routine, nutritional and clinical status. The ideal is to eat a small number of refined grains and have a healthy diet, ensuring that at least half of your grain intake comes from the whole grain version. Andrea Pereira warns that they should not be prioritized in a healthy diet, and their consumption should be reduced as much as possible. "Complex carbohydrates have more nutrients and fiber that help prevent chronic disease," she says.

Remembering that complex carbohydrates have a lower glycemic index, this is the case of brown rice, wholemeal flours, and their products (bread and pasta), tubers (potatoes and sweets, yams, cassava, manioc, yams), oats, among others.


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