A new study shows your diet quality may influence your risk of cognitive decline, including memory and thinking skills.
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Results show people with the healthiest diets were 24 percent less likely to have cognitive decline than people with the least healthy diets when followed for close to five years.
Reports on poor diet show that it’s a potential risk factor for cardiovascular disease and Alzheimer’s disease.
Previous research indicates that maintaining a heart-healthy Mediterranean-style diet is associated with cognitive decline.
However, this is the first large study to examine the association between diet quality and cognitive impairment, which includes memory loss, speed of response and judgment.
“We’ve known for quite a while that a good diet is related to cardiovascular health,” neurologist Jagan Pillai, MD says. “Now we’re seeing that your choice of diet not only affects your heart health, but also your cognition.”
Large multinational study examines effects of diet on cognitive decline
Researchers from McMaster University in Canada examined the dietary intake of over 27,000 people from 40 countries. All of them had diabetes or a history of heart disease, stroke or artery disease.
Dr. Pillai says that early cardiac risks are linked to worse cognitive function later in life.
Aged 55-years or older, the study participants were followed for nearly five years or until they experienced a heart attack, stroke, hospitalization from heart failure or death.
At the beginning of the study, participants’ thinking and memory skills were tested. They were tested again after two years, then once more after about five years.
They were also scored based on their food consumption. People who ate healthy foods like fruits, vegetables, nuts, soy and protein scored higher than those who ate deep fried foods.
“People with higher scores seemed to show a slower rate of decline,” Dr. Pillai says.
Fourteen percent of the people with the healthiest diet had cognitive decline. About 18 percent of people with the least healthy diets experienced cognitive decline.
Diet has more impact than previously thought
What’s most interesting, Dr. Pillai says, is that the researchers considered other factors that could affect the study’s results including exercise pattern and age, but the results were the same.
Prior to this research, the strongest evidence in reducing the risk of cognitive decline and dementia is for the positive impact of regular exercise.
“Even after you take into account other factors that may impact cognition, there’s still an effect from diet,” Dr. Pillai says.
Clearly, diet has more impact on brain health than we’ve previously thought.
A diet high in fruits, vegetables, nuts, fish, moderate alcohol use and very little red meat seems to be best. Other studies have shown similar results, specifically with the Mediterranean diet.
Some of the highest life expectancy and lowest heart disease rates in the world are associated with adopting a Mediterranean-style diet. The benefits appear to go beyond heart and brain health, too. People who follow the diet experience a better overall quality of life and kidney function.
“There’s no excuse to say that diet is not playing a role in cognitive impairment and brain changes over time,” Dr. Pillai says.