Eating chips and fries? Beware: Ultra-processed foods cause a sharp decline in sperm quality!

A 50g pack of potato chips may contain 280 calories. 3 medium-sized apples have around 285 calories. So, what’s your pick for a snack? Chips or apples? Do you find yourself thinking, “I’ll go for the chips, after all, it’s just 280 calories”? Well, then here’s some shocking news for you. Not all calories are equal. There is a stark difference between eating a pack of potato chips and apples. Because there is more to nutrition than calories. A new study has found that eating ultra-processed foods can lead to poor reproductive health in men.

A recent study by the researchers at the University of Copenhagen's NNF Center for Basic Metabolic Research (CBMR) found that consumption of ultra-processed foods can lead to a decline in sperm quality. The findings are published in the journal Cell Metabolism.

There has been a sharp rise in the obesity and type 2 diabetes rates, and obesity is the major driver behind it. The researchers also found that there has been a significant decline in sperm quality over the past 50 years, and ultra-processed foods are to blame for this. While scientists have long suspected these foods, it remains unclear whether the risk stems from the industrial nature of the ingredients themselves, the processing of the foods, or whether it’s because they lead people to eat more than they should.

The researchers have now discovered that the weight gain caused by the ultra-processed diet compared to a minimally processed diet (even when they eat the same number of calories) is the reason. They also found that a diet high in ultra-processed foods introduces higher levels of pollutants that are known to affect sperm quality. Along with increasing weight, these foods also disrupt hormones, affect sperm quality, and lead to poor reproductive quality in men.

“Our results prove that ultra-processed foods harm our reproductive and metabolic health, even if they’re not eaten in excess. This indicates that it is the processed nature of these foods that makes them harmful,” Jessica Preston, lead author of the study, at the University of Copenhagen's NNF Center for Basic Metabolic Research (CBMR), said in a statement.

The same calories do not necessarily mean they have similar nutritional value. To better understand this, the researchers compared the health impact of unprocessed and ultra-processed diets on the same person. The study involved 43 men aged 20 to 35, who spent three weeks on each of the two diets, with three months of ‘washout’ in between. Half of the participants started on the ultra-processed food, and the other half on an unprocessed diet. Half of the men also received a high-calorie diet with an extra 500 daily calories, while the other half ate the normal amount of calories, based on their size, age, and physical activity levels. Both the unprocessed and ultra-processed diets had the same amount of calories, protein, carbs, and fats.

The researchers noticed that the people on the ultra-processed diet gained around 1 kg of fat mass, compared to the unprocessed diet, regardless of whether they were on the normal or excess calorie diet. Other markers of cardiovascular health were also affected.

The researchers found a troubling spike in the level of the hormone-disrupting phthalate cxMINP, a substance used in plastics, in men on the ultra-processed diet. They also noticed a decrease in the levels of testosterone and follicle-stimulating hormone, which are crucial for sperm production, in men, who were on an ultra-processed diet.

“We were shocked by how many body functions were disrupted by ultra-processed foods, even in healthy young men. The long-term implications are alarming and highlight the need to revise nutritional guidelines to better protect against chronic disease,” senior author Professor Romain Barrès from the University of Copenhagen’s NNF Center for Basic Metabolic Research, and the Université Côte d’Azur, added.