This is how eating too many carbs disrupts your metabolism

Carbohydrate loading is a very well-known habit of athletes, but a new study shows that this is ineffective and doesn’t help body processes. Instead, it causes harm.

 Carbohydrates (photo credit: INGIMAGE)
(photo credit: INGIMAGE)

Carbohydrate loading before a big run is a well-known habit, but is it really healthy? 

A new study shows that consuming a large number of carbohydrates at once can actually disrupt the body's overall metabolic rate, causing metabolic dysfunction.

Researchers from Harvard-affiliated Brigham and Women's Hospital and Boston Medical Center discovered that eating too many carbohydrates leads to the breakdown of powerful antioxidants, a process that worsens as insulin production increases.

Sourdough bread with seeds (Credit: Courtesy)Sourdough bread with seeds (Credit: Courtesy)

Metabolism affects every cell in the body. Because this process helps the body's cells to receive energy, it’s important that nothing interferes with this process. However, previous studies linked obesity to a decrease in metabolism. The link between obesity along with type 2 diabetes and insulin resistance also suggests carbohydrate intake as a cause of metabolic distress.

To date, research has shown the effects of sugar consumption on the body's metabolism over time. Unfortunately, previous studies couldn’t assess how large amounts of carbohydrates affect the overall metabolism if consumed at once.

"When we treat people with type 2 diabetes, the focus is often on lowering blood sugar rather than preventing overeating carbs, which is very common in our society,” said Dr. Nawfal Istfan of Brigham's Endocrinology Division, in a university publication. He adds that “our research shows that if overeating isn’t controlled, some of the traditional ways of treating diabetes, such as giving more insulin to patients to lower blood sugar, may actually be more harmful." 

The researchers, whose study was published in the American Journal of Physiology-Endocrinology and Metabolism, conducted a study that included 24 women who were divided into two groups: one with a healthy body mass index (BMI) and one group with a high BMI in the range of overweight to obesity. None of these women suffered from diabetes.

All participants ate a large amount of carbohydrates at one time. Some of them ate more than 350 grams. After analyzing blood and fat samples, the researchers found that the antioxidant glutathione found in broccoli and mushrooms, for example, loses some of its electrons. Those with a higher BMI were more prone to this process, which led the researchers to hypothesize that cells take antioxidant electrons in order to fuel the fat conversion process from carbohydrates.

Overweight participants’ fat samples also revealed a decrease in metabolic function compared to those with type 2 diabetes and insulin resistance. Because insulin increases the absorption of carbohydrates by the cells, it increases the effects of metabolic dysfunction, because the cells aren’t equipped to cope with such a high volume of carbohydrates.

These results reinforced the theory that excess carbohydrates may lead to a decrease in metabolism. The reason is that too many carbohydrates force the cells to store them as fats. This process involves the conversion of carbohydrates into fats, which require electrons. According to the study, as excess fat is produced, electrons are "stolen" from other important metabolic processes, such as the formation of antioxidants.

The researchers summed up their findings by stating  that there are measurable differences between the subjects' metabolism, a crucial measurement which has been disregarded in medicine. Metabolic overfeeding varies between patients, and medical personnel need to understand this so they can provide appropriate dietary advice.