Study Links Dietary Copper to Better Cognitive Function in Older Adults

Copper is not usually associated with healthy eating, yet a new study has connected copper consumption in older adults’ diets with stronger cognitive function – an important result for research into healthy ageing.

Researchers at Hebei Medical University in China analysed dietary and health information from 2,420 US adults aged 60 and above. Their findings showed an association between higher dietary copper intake and better cognitive function.

Using several different assessments, the researchers found that participants consuming more copper achieved significantly higher scores than those consuming less. The analysis also indicated a threshold beyond which increasing copper intake appeared to offer no further benefit.

Dietary copper and cognitive function in older adults

"The current study indicates a potential association between dietary copper intake and enhanced cognitive function in American older adults, particularly among those with a history of stroke," write the researchers in their published paper.

"Dose–response analysis suggested an optimal copper intake level, with an inflection point of approximately 1.22 milligrams per day. However, further longitudinal studies are necessary to confirm these findings."

There are important limitations to consider. On two occasions, participants were asked to recall all food eaten during the previous 24 hours, and the scientists used those reports to estimate copper intake. This approach provides only a brief snapshot and may be affected by biases in self-reported information.

To examine the relationship in more depth, future research would need to track participants over a number of years and assess their copper intake with greater precision.

Consequently, the findings cannot establish a direct cause-and-effect relationship. Even so, the statistical association is sufficiently strong to justify additional study.

Why copper may support the brain

The result also aligns with earlier research reaching a similar conclusion: copper benefits the brain. It is known to support communication between neurons and energy production in the brain, while also helping to protect it from damage.

In that context, the findings are not unexpected. However, they help to measure the potential benefits of copper across a comparatively large group of older adults, using several cognitive tests, while identifying a potential optimum level of copper intake.

"Though copper is necessary for proper functioning of the brain, and deficiencies can lead to neurological disorders, excessive copper can be toxic, leading to oxidative stress and neurodegeneration," write the researchers.

An intake of 1.22 mg per day is roughly equivalent to a handful of walnuts or a bowl of lentils. Copper occurs in more foods than many people may realise, including mushrooms, dark chocolate, wheat bran, potatoes and oysters.

Micronutrients and healthy ageing

There is growing interest in micronutrients including magnesium, iron, selenium, zinc and copper, and in their possible role in keeping the brain sharp in later life. This builds on existing research into the links between diet and healthy ageing.

What people eat clearly has a substantial influence on brain health, although diet is far from the only contributing factor. Studies such as this may help guide improvements in prevention and treatment for brain conditions that commonly accompany old age.

"With the increase in the aging global aging population, the prevalence of cognitive impairment is also escalating," write the researchers.

"All forms of dementia, ranging from mild cognitive impairment to Alzheimer's disease, are marked by cognitive decline and are increasingly emerging as a significant global public health challenge."

The research was published in Scientific Reports.