People who eat the highest amount of ultra-processed foods such as drinks and chocolate may have a higher risk of developing dementia than those who eat the lowest, a study has indicated.
It also found that replacing ultra-processed foods with unprocessed or minimally processed foods was associated with lower risk.
According to the study, eating more unprocessed or minimally processed food equivalent to half an apple a day, while reducing ultra-processed food equivalent to a chocolate bar a day, is associated with a 3 percent reduced risk of dementia.
Ultra-processed foods – which are high in added sugar, fat and salt, and low in protein and fiber – include soft drinks, salty and sugary snacks, ice cream, hot dogs, fried chicken, canned baked beans, ketchup and flavored cereals. .
The researchers emphasized that their findings do not prove that ultra-processed foods cause dementia, and that they only show a link.
These foods may also contain food additives or molecules from packaging or produced during heating, all of which have been shown in other studies to have negative effects on thinking and memory.
Huiping Li, Tianjin Medical University
Study author Huiping Li, of Tianjin Medical University in China, said: “Ultra-processed foods are meant to be convenient and tasty, but they reduce the quality of a person’s diet.
“These foods may also contain food additives or molecules from packaging or produced during heating, all of which have been shown in other studies to have negative effects on thinking and memory.
“Our research not only found that ultra-processed foods are associated with an increased risk of dementia, it found that replacing them with healthy alternatives can reduce dementia risk.”
The study suggests that for every 10% increase in daily intake of ultra-processed foods, people had a 25% higher risk of dementia.
The research also found that replacing just 10% of ultra-processed foods with unprocessed or minimally processed foods, such as fresh fruit, vegetables, legumes, milk and meat, was associated with a 19% lower risk of dementia.
Researchers identified 72,083 people from the UK Biobank study, a large database containing the health information of half a million people.
They were aged 55 and over and did not have dementia at the start of the study.
After being followed for an average of 10 years, 518 were diagnosed with dementia.
It is encouraging to know that small and manageable changes in diet can make a difference to a person’s risk of dementia
Huiping Li, Tianjin Medical University
Researchers determined how much ultra-processed food people ate by calculating grams per day and comparing it to grams per day of other foods to create a percentage of their daily diet.
The participants were divided into four equal groups from the lowest percentage consumption of ultra-processed food to the highest.
Researchers found that ultra-processed foods made up an average of 9 percent of the daily diet of people in the lowest group, an average of 225 grams per day, compared to 28 percent for people in the highest group, or an average of 814 grams per day.
They say the main food group contributing to high ultra-processed food intake was beverages, followed by sugary products and ultra-processed dairy.
In the lowest group, 105 of the 18,021 people developed dementia, compared to 150 of the 18,021 people in the highest group.
Huiping Li said: “Our results also show that unprocessed or minimally processed foods increase by only 50 grams per day, which is equivalent to half an apple, a portion of corn or a bowl of bran cereal, while reducing ultra-processed foods by 50 grams per day a day, equivalent to a bar of chocolate or a portion of fish sticks, is associated with a 3% reduced risk of dementia.
“It is encouraging to know that small and manageable changes in diet can make a difference in a person’s risk of dementia.”
The findings are published in Neurology journal.