Study Indicates Increased Fruit Consumption Could Prevent Depression in Later Life

It’s well established that fruit in your diet increases fiber intake, elevates antioxidant levels, and boosts dietary variety. Now, new research shows that your fruit bowl may also hold potential for preventing depression later in life. 

A June 2024 study in The Journal of Nutrition, Health and Aging found that people in mid-life who ate more fruit had lower rates of depression in older age. The longitudinal study out of Singapore tracked nearly 14,000 participants for over 20 years. Those who consumed the most fruit (at least three servings per day) reduced their likelihood of age-related depression by at least 21%.

The findings could have meaningful impact for preventing a mental health condition that’s extremely common in older populations.

“Studies worldwide have estimated that the prevalence of late-life depressive symptoms ranges from 17.1% to 34.4%, and among those with mild or subclinical depressive symptoms, 8-10% may transition into major depression every year,” senior study author Woon Puay Koh, MBBS, PhD, professor at the National University of Singapore’s Healthy Longevity Translational Research Programme, told Health. “[This] is associated with reduced quality of life and increased risk of morbidity and mortality.”  

These troubling statistics led Koh and her research team to explore how diet in midlife might affect mental health in later years. Here’s a look at what they found.

The Journal of Nutrition, Health and Aging study began with data from as far back as 1993–1998. At this time, 13,738 adults in Singapore were asked to answer detailed questions about their consumption of fruit and vegetables. Their baseline age was 52.4 years old. Over two decades later, in a follow-up interview period of 2014–2016, when participants had an average age of 72.5, they were evaluated using the Geriatric Depression Scale, a clinical screening tool used in many countries to identify depression in older adults.

The more fruits subjects indicated eating in the 1990s questionnaire, the lower their likelihood of experiencing depression approximately 20 years later. The connection between fruit and better mental health wasn’t slight, either. Koh stated in a previous press release that participants who had at least three servings of fruits a day, compared to those with less than one serving a day, were able to reduce the likelihood of aging-related depression by at least 21%.

The fruits in question were 14 specific choices commonly eaten in Singapore. Among them, orange, tangerine, papaya, banana, and watermelon were specifically linked with reduced odds of depression.

According to Julie Pace, RDN, functional nutrition expert and owner of Core Nutrition Health and Wellness, this may affect how well the study’s conclusions apply to other populations. “The fruits and vegetables studied might differ from those typically consumed in Western diets, which could limit how these findings apply to Americans,” she told Health.

Another potential limitation she noted was the fact that the study was conducted solely on Singaporean adults of Chinese descent. Research shows that different genetic phenotypes and environments may impact numerous measures of health.   

The exact reasons why eating more fruit in your 40s or 50s might boost mental health in older age aren’t clear, Koh said, but multiple factors could be at play.

“Oxidative stress and subsequent neuroinflammation are the two well-established pathways [of depression],” she said. Fruits have something to offer for preventing these issues. “Fruits generally contain high levels of antioxidants and anti-inflammatory micronutrients, such as vitamin C, carotenoids, and flavonoids, and these nutrients have been shown to reduce oxidative stress and inhibit inflammatory process in the body.” Koh believes this is the most likely explanation for the study’s findings.

Vegetables, which were also evaluated in the study, had no observable impact on depression later in life—a finding that surprised the researchers. However, Koh has a theory about why this might be. Though veggies are also rich sources of antioxidant compounds, their typical preparation methods could reduce their anti-inflammatory impact. “Fruits are typically eaten raw as snacks throughout the day, whereas vegetables are usually cooked for meals,” she noted. “Cooking is known to be a process which may change the bioavailability and activity of nutrients in vegetables, and thereby limit the protective effects of these nutrients on depression.”

Despite the study’s intriguing findings about fruit consumption in midlife, Koh said it doesn’t mean middle age is the best (or only) time to eat more fruit.

“We asked about [subjects’] intake of 14 fruits and 25 vegetables most commonly consumed at that time in Singapore, but we did not ask about the age they started their habit,” she noted. “Other studies done elsewhere have also discovered the benefit of including fruits in diets that were associated with better mental health in children and young people.” For this reason, she recommends bumping up fruit in your diet at as young an age as possible.

As for how many fruits to eat per day? “For most adults, three to four servings of fruit per day (1.5 to 2 cups) is usually sufficient,” Pace said. Going past this number is generally OK, too, but may bring some undesirable side effects. “Overconsumption of certain fruits may cause digestive issues like stomach upset.”

Increasing fruit shouldn’t lead to ditching vegetables, either. “The message is not to ask people to replace vegetables with fruits, but to eat fruits for the after-meal or in-between meal snacks, instead of sweetened desserts, savory snacks, and ultra-processed foods,” Koh said.

Fortunately, fruit is widely available and generally easy to transport. But besides tossing an apple or banana in your lunchbox, Pace recommends a few simple tactics to increase consumption. Try any of the following:

Each time you add another fruit, you can rest assured you’re doing right by your health in general—and perhaps specifically for mental health in the future.