A recent study conducted at Yale University and published in the journal Science Immunology on November 15 suggests that the ketogenic diet, known as the Keto Diet, might have potential in combating influenza infections. The research discovered that mice fed a ketogenic diet, which is characterized by low carbohydrate intake, high fat content, and moderate protein levels, exhibited enhanced resistance to the flu compared to mice fed high-carb diets.
According to co-senior author Vishwa Deep Dixit, PhD, a doctor of veterinary medicine and a professor of comparative medicine and immunology at Yale, ‘This study shows that the way the body metabolizes fat to produce ketone bodies from the food we eat can provide the immune system with the energy it needs to combat flu infections.
How Does the Keto Diet Work?
A ketogenic diet is effective in promoting weight loss by significantly reducing carbohydrate intake, which includes foods like bread, pasta, and sugary items, while increasing the consumption of meats, dairy products, fats, and non-starchy vegetables.
This dietary approach induces a metabolic state known as ketosis, where the liver converts fat into ketones, serving as an alternative energy source when glucose is limited.
Furthermore, research has demonstrated its potential benefits in managing blood sugar levels among individuals with type 2 diabetes. Some studies, such as one published in Federal Practitioner in February 2017, have also indicated that a ketogenic diet may enhance tumor response in cancer patients.
Another study conducted at the University of California in Davis in 2017 observed that mice following a high-fat diet experienced a 13 percent longer lifespan compared to those on a high-carb diet.
Knowing How Keto May Affect the Flu Virus
In their recent study, Dr. Dixit and his colleagues discovered that the ketogenic diet effectively hindered the formation of inflammasomes, which are activators of the immune system known to trigger harmful immune responses.
Encouraged by this finding, the researchers sought to investigate how the diet could impact the influenza virus.
They divided a group of influenza-infected mice into two: one group received a keto diet consisting of less than 1 percent carbohydrates, while the other group received a standard diet with 58 percent carbohydrates.
The ketogenic diet triggered the release of gamma delta T cells, a type of immune system cell responsible for producing mucus in the lung cell linings. Increased mucus production helps capture and eliminate the flu virus from the body, according to the researchers.
Furthermore, the study revealed that the keto diet did not provide protection against the influenza virus in mice specially bred without gamma delta T cells, confirming the critical role these cells play in fending off the flu.
Emily Goldberg, PhD, a postdoctoral associate at the Yale School of Medicine involved in the research, commented on the activation of gamma delta T cells by the keto diet, stating that the reasons behind this phenomenon would be explored further in future studies.
Jan Rystrom, RD, a certified diabetes educator at the Swedish Medical Center in Seattle, who was not part of the Yale study, explained that high-carb diets tend to stimulate inflammatory markers that inhibit immune function, potentially accounting for the keto diet’s effectiveness.
However, some dietitians and medical experts hold the belief that low-carb diets can compromise the immune system. Lack of carbohydrates may lead to reduced energy levels and overall health weakening. Additionally, there is evidence suggesting that keto diets may harm the gut microbiome, which is essential for overall well-being.
Rystrom emphasized that keto diets vary widely, and those that prioritize plant-based foods are more likely to support a healthier gut microbiota.
Dr. Goldberg noted that while it is true that the immune system typically requires increased glucose utilization for an effective immune response against infection, it’s important to remember that there is still limited glucose availability, even during a keto diet.
Flu Shot Still Remains the Best Protection
While Rystrom suggests that the Yale study provides support for the anti-inflammatory effects of nutritional ketosis, she emphasizes that a keto diet should not be considered a primary treatment for the flu.
William Schaffner, MD, an infectious-disease specialist at Vanderbilt University in Nashville, Tennessee, has not come across substantial data linking diet to flu protection.
Dr. Schaffner finds the study intriguing and believes that gaining a better understanding of the body’s defense mechanisms against the flu could lead to more effective treatments and prevention strategies.
He points out that there is some evidence suggesting that obesity might result in a weaker response to the flu vaccine, which could indicate a potential connection between diet and flu protection.
However, it is essential to conduct research in humans to confirm whether the keto diet can indeed offer effective protection against the flu.
Len Horovitz, MD, a pulmonary specialist at Lenox Hill Hospital in New York City, highlights the differences between humans and mice. He emphasizes that tens of thousands of people die from influenza each year in the United States alone and emphasizes that there is no better alternative for protection against the flu than getting a flu shot.