Don’t believe the hype: health headlines dissected
Research appears to show that eating one or two servings of leafy green vegetables per day could slow the memory decline associated with ageing. The newspapers greeted the study with headlines suggesting that eating your greens could actually stave off dementia. So, does eating a salad a day really keep the doctor away?
Researchers at Rush University Medical Center in Chicago, led by study author Martha Clare Morris, aimed to increase the understanding of biological mechanisms underlying the association between nutrients in green leafy vegetables and cognitive decline.
The primary nutrients and bioactives in greens such as spinach, rocket and kale include vitamin K, lutein, nitrate, folate and kaempferol.
The participants were divided into five equal groups based on how often they ate leafy green vegetables.
For those who ate the most, the rate of decline in scores on thinking and memory tests was slower by 0.05 standardised units per year than the rate for those who ate the least leafy greens – an equivalent difference to being 11 years younger.
This was a prospective study of 960 participants of the Memory and Aging Project. Participants aged 58–99 years – without an existing dementia diagnosis – completed a food frequency questionnaire and had less than two cognitive assessments over a mean period of 4.7 years.
The study results, published in the online issue of Neurology, appeared to show a link between consumption of leafy greens and a slowing of cognitive decline.
The researchers concluded: ‘Consumption of approximately one serving per day of green leafy vegetables and foods rich in phylloquinone, lutein, nitrate, folate, α-Tocopherol, and kaempferol may help to slow cognitive decline with aging.’
The study does build on the body of research that shows a healthy diet could slow memory loss, and proves a fragile link between eating leafy green vegetables and a reduction in cognitive decline and memory loss.
As dementia itself wasn’t measured in the study, at this stage it can’t be concluded that the diet could prevent dementia. In addition, some participants were followed-up for the relatively short period of two years, and it can take longer for memory loss and dementia to develop.
Morris herself pointed out that the study merely showed an association. Dr James Pickett, Head of Research at Alzheimer’s Society, agreed, but added: “What’s good for the heart is good for the head. A healthy diet rich in essential nutrients, combined with regular exercise and avoiding smoking, can help to reduce your risk of developing dementia.”
What the press said:
“A salad a day keeps dementia away, researchers say”
“Eating salad could help stave off dementia, new research reveals”
“A salad a day keeps brains 11 YEARS younger”