Experts are suggesting that incorporating kimchi into your winter diet might be a powerful defense against this year’s formidable flu season. This traditional Korean dish, renowned for its unique flavor, is a blend of fermented vegetables such as napa cabbage and radish, typically enjoyed alongside rice and stews.

Priced at approximately $2 per serving, kimchi has been celebrated for its rich supply of vitamins and probiotics—beneficial bacteria that support digestive health and bolster the immune system. Recent findings, however, indicate that kimchi’s benefits might extend to warding off viral infections like the flu.

A study conducted in South Korea tracked the health of 13 overweight participants over three months. The participants were divided into two groups: one consumed kimchi powder daily, while the other received a placebo.

The study’s blood tests revealed that individuals consuming about an ounce of kimchi each day exhibited increased levels of certain genes that present antigens on the cell’s surface. These antigens are recognized as threats by the immune system.

This recognition enables white blood cells, which are crucial in fighting infections, to identify and respond to these threats effectively. Consequently, the immune system is activated to eliminate potential illnesses, potentially reducing the risk of contracting the flu.

This allows disease-fighting white blood cells to detect them and activate the rest of the immune system to drive the threat out, which could lower the chance of becoming ill. 

The findings come as this season’s ‘super flu’ ravages the US. Though infections finally show signs of slowing, with 19 percent of tests coming back positive compared to 25 percent the week before, experts have warned flu season is far from over.

The CDC also reported 15 child deaths from the flu last week alone, with parents urging others to get their yearly vaccines to help slow the spread. 

As the flu rages on in the US, experts have warned an unlikely fermented vegetable may reduce the risk of getting sick (stock image)

The study, published in November 2025 in the journal NPJ Science of Food, looked at 13 overweight but otherwise healthy adults. They were randomly assigned either to a placebo or kimchi group. 

The average age was 48, and the majority of participants were women.  

People in the kimchi group consumed about 3,000 milligrams of kimchi powder each day, the equivalent of one ounce of kimchi.  

Using blood tests, researchers found people who ate kimchi had cells that expressed higher amounts of MHC class II genes, which prop antigens, molecules the immune system recognizes as abnormal, up to the surface of cells. 

This allows white blood cells called helper T cells to detect the antigens and activate other immune cells to fight off infections. 

This means participants who ate kimchi every day were more likely to have their immune systems recognize viruses, potentially leading to them recovering faster or avoiding illnesses altogether. 

The team also suggested kimchi kept immune cells from becoming too active, lowering the risk of tissue damage caused by an excessive immune response.  

Kimchi has long been touted for its gut benefits, but the new study suggests it may lower the risk of viruses (stock image)

Dr Wooje Lee, lead study author of the World Institute of Kimchi, a government-funded research organization that studies fermentation, said: ‘Our research has proven for the first time in the world that kimchi has two different simultaneous effects: activating defense cells and suppressing excessive response.’

Experts believe fermented foods such as kimchi introduce healthy probiotics that counteract pathogens, strengthen the lining of the gut and boost overall immune function.  

In the study, kimchi powder was fermented with the healthy bacteria Leuconostoc mesenteroides, which has been shown to improve digestion, immune support and inflammation. 

There were several limitations, however, such as the small sample size, so the researchers emphasized larger studies are still needed on the relationship between kimchi and immune health.