There are more benefits to following a healthy low-fat diet than shedding pounds and dropping a few pant sizes. Now, scientists have discovered eating less fat could also help protect you against infectious diseases like Covid-19.
Researchers from the University of California – Riverside found ‘concerning’ changes in gene expression – how your genes are physically expressed – in subjects that followed diets high in fat.
Results of the study showed high-fat diets increased the gene expression of proteins in the body that are used by Covid spike proteins to enter and infect a host.
Senior author Frances Sladek, a UCR cell biology professor, said: ‘Word on the street is that plant-based diets are better for you, and in many cases that’s true. However, a diet high in fat, even from a plant, is one case where it’s just not true.’
Researchers said their study demonstrates high-fat diets not only affect the genes linked to obesity, colon cancer and irritable bowls, but the diets also have an impact on genes related to the immune system, brain function and risk of Covid-19.
Compared to mice who followed a low-fat diet, those that consumed a high-fat diet had ‘concerning’ changes in their genes
The study, published in Scientific Reports, saw researchers feed three groups of mice one of three diets where at least 40 percent of the calories came from fat: One based on saturated fat from coconut oil; one based on monosaturated fat from a genetically modified soybean oil; and one based on polyunsaturated fats from conventional soybean oil.
The caloric and fat makeup of the mice diets closely resembles what experts say a typical American diet consists of. While some fat is necessary, a diet should not be comprised of more than 10 to 15 percent of fat.
Measurements taken from the mice were then compared to a control group that followed a low-fat diet.
Over the 24-week study period, it was discovered that, compared to a low-fat diet, all three groups of mice experienced ‘concerning changes in gene expression.’
Researchers analyzed genes in four areas of the mice’s digestive system and found ‘dysregulation’ of genes in multiple tissues in the animals following each of the high-fat diets.
The changed genes were those involved in how the body metabolizes drugs, those related to irritable bowel disease and colon cancer, as well as genes that affect the bacterial makeup of the gut and regulate susceptibility to infectious diseases like Covid-19.
The results showed all three high-fat diets increase the gene expression of proteins that are used by Covid spike proteins to enter and infect the body, making it more susceptible to an infection.
Genes related to the immune system grew weaker and functioned at a slower rate in mice eating high-fat diets than they did in the control group of those consuming low-fat diets.
Among the three types of diets, the one based on coconut showed the greatest number of changes, followed by the conventional soybean oil.
The authors said the differences observed between the two soybean oils suggest polyunsaturated fats play a role in how genes are expressed.
Additionally, the bacterial makeup of the gut – the microbiome – was changed the most in mice fed the soybean oil diet.
Researchers expressed concern over the results because soybean oil is the most commonly consumed oil in the United States.
Co-author Sladek said: ‘We saw pattern recognition genes, ones that recognize infectious bacteria, take a hit.
‘We saw cytokine signaling genes take a hit, which help the body control inflammation.
‘So, it’s a double whammy. These diets impair immune system genes in the host, and they also create an environment in which harmful gut bacteria can thrive.’
The team also found the high-fat diets increased signs of stem cells in the colon, which can be a precursor to colon cancer.
Microbiologist Poonamjot Deol, co-first author of the study, assured people that one night of indulging in a fatty meal won’t harm you, but years of an unhealthy diet has detrimental impacts.
He added: ‘Some people think, “Oh, I’ll just exercise more and be okay,” but regularly eating this way could be impacting your immune system and how your brain functions.
‘You may not be able to just exercise away these effects.’