Eating this fruit every day could cut your risk of depression by 20%, say Harvard researchers

A healthy diet is essential for staying in good shape—something we all know. But in an interesting twist, new research reveals that eating one specific fruit can have a surprisingly positive impact on brain health.

The proverb that inspires

You’ve probably heard the old saying, “An apple a day keeps the doctor away.” While this familiar proverb isn’t just about apples, it’s a reminder of the importance of a healthy lifestyle. Building on the idea that fruit can benefit your health, doctors from Harvard Medical School and Massachusetts General Hospital recently published a study in Microbiome showing that eating an orange every day may lower the risk of depression by 20%.

Oranges, a bacterium, and a breakthrough

Their findings come from the extensive Nurses’ Health Study II (NHS2), where more than 100,000 women have shared detailed updates on their lifestyle, diet, medication, and health every two years since 1989. To further their research, the scientists also conducted DNA sequencing on stool samples from a group of NHS2 participants, uncovering valuable clues about how oranges might support mental well-being.

The key appears to be a particular gut bacterium, Faecalibacterium prausnitzii. The study found that this beneficial microbe is more abundant in people without depression and that higher citrus intake is linked with increased levels of F. prausnitzii. Similar patterns have even been observed in men, according to additional research.

From the gut to the brain

How does this work? The researchers suggest that F. prausnitzii may affect the production of two important neurotransmitters—serotonin and dopamine—by cells in the gut. These chemicals not only help regulate digestion but also travel to the brain, where they can improve mood.

Still, the doctors caution that while eating oranges might help reduce the risk of depression, they shouldn’t be considered a treatment for the condition. More clinical trials are needed to confirm these promising results.

Nathalie Mayer

Journalist

Born in Lorraine on a freezing winter night, storytelling has always inspired me, first through my grandmother’s tales and later Stephen King’s imagination. A physicist turned science communicator, I’ve collaborated with institutions like CEA, Total, Engie, and Futura. Today, I focus on unraveling Earth’s complex environmental and energy challenges, blending science with storytelling to illuminate solutions.

Marie Pireddu

Marie Pireddu is a French-English translator specializing in digital marketing, technology, and mobile apps. She is also a business English trainer for professional adults, helping clients master English for international business, with a focus on American culture and corporate communication.