Eating more fruit can prevent depression in old age

It’s well known that including fruit in your diet increases fiber intake, boosts antioxidant levels, and increases dietary variety, but new research now shows that your bowl of fruit may also help prevent depression later in life.

A study from June 2024 in The Journal for Nutrition, Health and Ageing found that people in midlife who ate more fruit suffered less from depression in old age. The longitudinal study from Singapore followed nearly 14,000 participants for 20 years. Those who ate the most fruit (at least three servings a day) reduced their risk of age-related depression by at least 21%.

The findings could have a significant impact on the prevention of a mental illness that is extremely common among older people.

“Studies worldwide have estimated that the prevalence of depressive symptoms ranges from 17.1% to 34.4% among adults, and from 8-10% among people with mild or subclinical depressive symptoms. can progress to major depression every year,” said lead study author Woon Puay Koh, MBBS, PhD, professor at the Healthy Longevity Translational Research Programme at the National University of Singapore Health“(This) is associated with reduced quality of life and increased risk of morbidity and mortality.”

These disturbing statistics prompted Koh and her research team to investigate how midlife nutrition might affect mental health in later years. Here’s a look at their findings.

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

The more fruit subjects reported eating in the 1990s questionnaire, the less likely they were to suffer from depression about 20 years later. The link between fruit and better mental health was not small either. Koh stated in an earlier press release that participants who ate at least three servings of fruit per day were able to reduce their odds of age-related depression by at least 21% compared to those who ate less than one serving per day.

The fruits studied were 14 specific types commonly consumed in Singapore. Among them, orange, tangerine, papaya, banana and watermelon were specifically associated with a lower risk of depression.

According to Julie Pace, RDN, functional nutrition expert and owner of Core Nutrition Health and Wellness, this could impact how well the study’s conclusions apply to other populations. “The fruits and vegetables studied may be different from those typically consumed in the Western diet, which could limit the generalizability of these results to Americans,” she said Health.

Another potential limitation she cited was the fact that the study was conducted exclusively on Singaporean adults of Chinese descent. Research shows that different genetic phenotypes and environments can influence numerous health indicators.

The exact reasons why eating more fruit in your 40s or 50s might improve mental health in old age are not clear, Koh said, but several factors may play a role.

“Oxidative stress and the resulting neuroinflammation are the two known causes (of depression),” she said. Fruit can help prevent these problems. “Fruits in general contain high levels of antioxidants and anti-inflammatory micronutrients such as vitamin C, carotenoids and flavonoids. These nutrients have been shown to reduce oxidative stress and inhibit inflammatory processes in the body.” Koh believes this is the most likely explanation for the study’s findings.

Vegetables, also examined in the study, had no discernible impact on depression later in life – a result that surprised the researchers. However, Koh has a theory as to why this might be the case. Although vegetables are also rich in antioxidants, typical preparation methods could reduce their anti-inflammatory effects. “Fruits are usually eaten raw as snacks throughout the day, while vegetables are usually cooked with meals,” she noted. “It is known that cooking is a process that can alter the bioavailability and activity of nutrients in vegetables, thereby limiting the protective effects of these nutrients on depression.”

Despite the study’s interesting findings on midlife fruit consumption, Koh says this does not mean that midlife is the best (or only) time to eat more fruit.

“We asked participants about their intake of 14 fruits and 25 vegetables that were most commonly consumed in Singapore at the time, but we did not ask about the age at which they started this habit,” she noted. “Other studies conducted elsewhere have also found the benefits of including fruit in the diet, which were associated with better mental health in children and adolescents.” For this reason, she recommends increasing the proportion of fruit in the diet as early as possible.

And how much fruit should you eat per day? “For most adults, three to four servings of fruit per day (1.5 to 2 cups) is usually enough,” Pace said. Even an excess is generally OK, but can cause some unwanted side effects. “Excessive consumption of certain fruits can cause digestive problems such as an upset stomach.”

But eating more fruit shouldn’t mean giving up vegetables either. “The message is not to tell people to replace vegetables with fruit, but to eat fruit as a snack after meals or in between meals, instead of sweetened desserts, savory snacks and highly processed foods,” Koh said.

Fortunately, fruit is widely available and generally easy to transport. But beyond an apple or banana in your lunchbox, Pace recommends a few simple tactics to increase consumption. Try these:

• Adding frozen or fresh fruit to smoothies
• Yoghurt topping with berries
• Prepare colorful salads with fruit
• Combine fruit with dip as a snack
• Drizzle your favorite fruit with chocolate sauce for dessert
• Adding fruit to oatmeal or cereal

Every time you add another fruit, you can be sure that you are doing something good for your health in general – and perhaps your future mental health in particular.