A daily fruit snack that may ease depressive symptoms in older adults

Feeling down? Depression affects as many as one in three older adults.

It is not considered a normal part of aging, though it is more common among people with health issues such as heart disease or cancer, restricted mobility, or sleep troubles — all of which become more likely with age.

Now, a new study suggests that a simple, wholesome treat may help improve older adults’ mood.

One possible mood-boosting option is blueberries, according to new research.

Researchers in Boston found that three months of blueberry powder was linked to better depressive symptoms.

Here is what they believe may be driving the effect.

Blueberries and mood

The pilot study included 18 participants aged 65 and older who had depressive symptoms.

They were divided into two groups: one took 48 grams — about 2 cups — of freeze-dried blueberry powder each day for three months, while the other received a placebo and only thought they were getting blueberry powder.

By the end of the study, both groups showed improved mood and fewer depressive symptoms. The size of the benefit was similar in each group, and there was no statistical difference between them.

“While changes in mental well-being outcomes are not different between groups, they appear to be ‘improvements’ of stronger magnitude in the blueberry group, with less variability compared to the placebo group,” the researchers wrote.

The gut-brain connection

The researchers thought blueberries might alter the gut microbiome in a way that could support mental health.

Other studies suggest that gut microbes influence the production and regulation of neurotransmitters that play major roles in mood and stress, including GABA and serotonin. Through the gut-brain axis, the vagus nerve carries signals directly between the gut and the brain.

In this study, people who ate blueberries every day did show some small changes in their gut microbiome.

Five bacterial enzymes increased, and the authors highlighted polyamine-transporting ATPase, which could help boost GABA.

This neurotransmitter slows brain activity and helps calm the nervous system. Some research has found lower GABA levels in people with depression.

Why more research is needed

The researchers stressed that although the blueberry and placebo groups did not differ statistically in mood changes, a larger and more diverse study might show a different result.

“This pilot study was designed to test intervention feasibility and gather the preliminary data on outcomes that are needed to estimate power of a larger trial,” they wrote.

They also noted that the sample was very small and not very diverse, with most participants being white women.

Supplements aimed at improving mood through the gut are becoming more popular, including “psychobiotics” — probiotics that some studies have linked to better mood. Still, not all experts are convinced.

“[Doctors] have to be incredibly cautious about recommending this for patients because the evidence is still being worked out,” gastroenterologist Dr. David Levinthal, director of UPMC’s Neurogastroenterology & Motility Center, told The Post in a separate story.

Other experts argue that instead of adding supplements, people should cut back on junk food.

With blueberries, the benefit may come less from adding helpful bacteria and more from anthocyanins, the pigments that give berries their blue color. Authors of a 2024 study said these compounds can inhibit MAO, which breaks down key mood-related neurotransmitters such as serotonin, dopamine and noradrenaline.