Diet outperforms five others for brain health – lowering the risk of cognitive decline by 41%

The research, led by Hui Chen of the Harvard TH Chan School of Public Health, analysed data from more than 159,000 participants.

The DASH diet – which stands for Dietary Approaches to Stop Hypertension – showed the strongest protective effects on brain function compared to five other healthy eating patterns, with leafy greens, fruits, fish and tea all linked to better cognitive outcomes.

Yellow vegetables and other vegetables were also associated with brain health.

On the flip side, however, some foods were connected to poorer cognitive performance.

Fried potatoes, red and processed meats, and sugary drinks all showed negative associations in the research.

Perhaps surprisingly, eggs, nuts and seeds were also linked to worse cognitive outcomes in this particular study. Wine and salad dressing, meanwhile, appeared alongside the brain-friendly foods.

The researchers drew on data spanning more than three decades, from 1986 to 2017, using information from the Nurses' Health Study, Nurses' Health Study II and Health Professionals Follow-Up Study.

Six different dietary patterns were examined in total, including plant-based and anti-inflammatory food plans.

The participants had an average age of 44, and women made up about 83 per cent of the group.

To measure cognitive changes, the team asked participants about perceived shifts in memory and attention, while also conducting telephone-based assessments to gauge actual cognitive function.

Following the DASH-style diet during the ages 45 to 54 showed particularly strong effects.

The researchers concluded that their findings "support the importance of healthy eating as part of midlife brain health strategies and motivate pragmatic and implementation research to translate these findings into scalable programs".

But they were upfront about some limitations, because the cognitive decline data were self-reported, the team acknowledged they "may be influenced by differences in health awareness or reporting tendencies".

There's also the question of how widely these results apply, as the participants were mostly white, highly educated healthcare professionals.

Still, the connection between blood pressure control and brain health aligned with previous research, giving the findings added weight.