A new study from the University of Hawaii Cancer Center in Manoa (Honolulu), published in the journal Neurology, found that eating high-quality plant foods is linked to a lower risk of Alzheimer’s disease and other forms of dementia.
“A plant-based diet has been shown to lower the likelihood of conditions like diabetes and high blood pressure, but less is known about its effect on Alzheimer’s disease and other forms of dementia,” said lead author Son-yi Park.
“Our study showed that the quality of a plant-based diet matters: a higher-quality diet was linked to a lower risk, and a lower-quality diet was linked to a higher risk,” she said.
Could a plant-based diet actually be unhealthy?
A plant-based diet means eating more plant foods than animal products such as meat, dairy, and eggs.
But a plant-based diet can be healthy or unhealthy — higher or lower quality. A healthy plan prioritizes beneficial plant foods such as:
- whole grains
- fruits
- vegetables
- plant-based oils
- nuts
- legumes
- tea and coffee
An unhealthy plant-based diet includes less healthy items like:
- refined grains
- fruit juices
- potatoes
- added sugar
The researchers did not examine vegetarian or vegan diets in their study.
What did the scientists find?
The team enrolled 92,849 people in an almost 11-year study, and participants’ average age at the start was 59. The group included African Americans, Japanese Americans, Latinos, Native Hawaiians, and White participants. During the study period, 21,478 people developed dementia.
At the start of the study, participants completed questionnaires about their diets. The scientists then rated how closely each diet matched a healthy or unhealthy plant-based pattern. They analyzed how much of the healthier and less healthy plant foods volunteers ate, along with animal fats, meat, dairy, eggs, and seafood. The team adjusted for factors such as age, physical activity, and the presence of diabetes.
First, the researchers estimated participants’ dementia risk based on their overall adherence to plant-based foods. They found that people who ate the most plant-based foods had a 12 percent lower risk of developing dementia compared with those who ate the least.
But the researchers were most interested in how participants’ diets changed over the study period.
Compared with people whose diets stayed the same, those whose diets shifted the most toward unhealthy foods had a 25 percent higher risk of developing dementia. Meanwhile, people whose diets shifted the most toward healthy eating had an 11 percent lower risk.
Dr. Park summarized: “We found that switching to a plant-based diet even later in life and cutting out low-quality plant foods were associated with a lower risk of Alzheimer’s disease and other types of dementia.”
She emphasized that it’s not enough to eat plant-based foods — those foods need to be high quality.
Photo: Openverse, Unsplash
