Kloe Quill

The gut has long been linked to overall health, underscoring the importance of feeding it well.

A new study shows that eating citrus fruits, such as oranges, may lower the risk of depression by about 20% — and experts say it’s due to the way it interacts with the stomach.

The study, published in the journal Microbiome, found that the positive effects of citrus are linked to how the fruits impact the gut microbiome, which includes the bacteria living in the stomach.

The researchers analyzed data from the Nurses’ Health Study II (NHS2), which began in 1989 and tracked chronic diseases among 100,000 womenin the U.S., according to a press release.

The participants provided information about their lifestyle, diet, medication use and health. They also provided stool samples for DNA analysis.

"We found that regularly eating citrus may lead to more than a 20% reduction in future risk for depression," lead author Raaj Mehta, MD, an instructor in medicine at Harvard Medical School and physician at Massachusetts General Hospital, told Fox News Digital. 

"Eating citrus was linked to a greater abundance of F. prausnitzii, a gut bacteria that may make chemicals that boost production of serotonin and dopamine, which can help you feel happier."

Based on the abundance of this bacteria, researchers believe there may be a link between citrus fruits and improved mental health.

"When we look at people’s total fruit or vegetable consumption, or at other individual fruits such as apples or bananas, we don’t see any relationship between intake and risk of depression," Mehta noted.

The researcher said he was surprised by the finding.

"If you had asked me to name a ‘brain food’ before starting our study, I would not have said oranges. I probably would have told you that we would find a signal for salmon or nuts," he shared.

Citrus fruits aren't the only food that can boost gut health, experts agree.

Foods high in fiber like vegetables, legumes and whole grains are great for the gut, according to registered dietitian nutritionist Tanya Freirich, who is based in Charlotte, North Carolina.

"We know that complex carbohydrates are better for our gut health than refined carbohydrates and sugar, and that whole foods are more beneficial than processed foods," she told Fox News Digital.

Foods that contain probiotics are also beneficial for gut health, according to the expert. These can include yogurt, kombucha and other fermented foods.

Citrus can be incorporated into the diet in many ways, Freirich said.

"Eat an orange as a snack, add lemon or lime juice to marinate your fish or animal protein for dinner, or add grapefruit pieces into a salad," she suggested.

This doesn’t mean those already on mental health treatments should ditch their prescriptions for a grapefruit, however.

"It’s hard to compare the effectiveness of citrus to traditional antidepressants [such as SSRIs]," said Mehta.

"We’re talking about preventing depression, and those drugs are usually used to treat depression once a person is already experiencing it."

The study did have some limitations, the researcher acknowledged.

"Our study was only conducted among women, but there is no reason why this would not apply to men as well," he told Fox News Digital. "We found no evidence that age, diet and lifestyle meaningfully affect our findings."

While the results do not prove that eating citrus prevents depression, researchers observed that the greatest benefit is seen with about one serving of citrus per day — approximately one medium orange.

"Since eating fruits and vegetables is generally good for you, I happily enjoy my daily orange," he shared with Fox News Digital.

In the future, citrus consumption could be explored as part of larger strategies for managing depression, but more research is needed before drawing such a conclusion, according to Mehta.

"If comfort foods make you feel happy in the short term, why can’t healthy foods like citrus - ‘mood foods’ - make you feel happier in the long term?"

Fox News