Adding a serving of kimchi to your winter diet could be a simple strategy to bolster your defences against this season's aggressive influenza strains, according to new scientific findings.
The Science Behind the Spicy Staple
A recent study from South Korea, published in November 2025 in the journal NPJ Science of Food, provides fresh evidence for kimchi's immune-boosting potential. Researchers from the government-funded World Institute of Kimchi tracked 13 overweight but otherwise healthy adults over a three-month period.
The participants, with an average age of 48 and mostly women, were split into two groups. One consumed roughly 3,000 milligrams of kimchi powder daily—equivalent to about one ounce of fresh kimchi—while the other received a placebo.
How Kimchi Activates Immune Defences
Blood analysis revealed a significant difference in the kimchi group. These individuals showed higher expression of MHC class II genes. These genes play a crucial role by moving antigens—molecules flagged as threats by the immune system—to the surface of cells.
This process acts like raising a flag, allowing disease-fighting white blood cells, known as helper T cells, to spot the danger. This detection then triggers a full immune response to eliminate the threat, potentially leading to faster recovery or even preventing illness altogether.
Lead author Dr Wooje Lee stated the research proved, for the first time, that kimchi has two simultaneous effects: activating defence cells and suppressing an excessive immune response, which can cause tissue damage.
A Timely Discovery Amid Flu Season
The findings emerge as a so-called 'super flu' continues to impact populations, notably in the United States. Although infection rates show signs of slowing—with positive tests dropping from 25% to 19% in a week—health experts warn the season is far from over.
The US Centers for Disease Control and Prevention (CDC) reported 15 child deaths from flu in just one week, underscoring the virus's severity and prompting renewed calls for annual vaccination.
Experts have long praised kimchi, a staple of Korean cuisine made from salted and fermented vegetables like napa cabbage and radish, for its vitamins and gut-healthy probiotics. This study suggests its benefits extend directly to antiviral immunity.
The kimchi powder used in the research was fermented with Leuconostoc mesenteroides, a bacterium linked to improved digestion, reduced inflammation, and immune support.
While promising, the researchers acknowledge the study's small sample size and emphasise that larger-scale investigations are needed to fully understand the relationship between kimchi consumption and immune health.
