People who consume more dietary fiber are less likely to develop dementia
Many people think of dietary fiber as being good for your stomach, or good for your health in general.
However, the health benefits of dietary fiber may be greater than many people realize.
A research group at the University of Tsukuba has recently announced that people who consume more dietary fiber in their daily diet have a lower risk of developing dementia
(dementia requiring nursing care). This is the first time in the world that this has been verified.
Analysis of dietary fiber intake and risk of developing dementia
The study involved 3,739 local residents of Akita, Ibaraki, and Osaka who were between the ages of 40 and 64 and participated in a nutritional survey between 1985 and 1999 in the CIRCS (Circulatory Risk in Communities Study), a large-scale study of Japanese health.
These are 3739 community members from Akita, Ibaraki, and Osaka who were aged 40-64 years and participated in the nutritional survey between 1985 and 1999.
They were followed for up to 21 years, from 1999 to 2020, to determine how many people would develop dementia requiring nursing care during that time.
Based on information from the previous day’s diet, the intake of dietary fiber (soluble and insoluble) and fiber-rich food groups such as potatoes, vegetables, and fruits were
calculated, and the subjects were classified into four groups according to their intake of each. Then, after statistically adjusting for the main risk factors for dementia, they examined
the risk of dementia requiring care in the other groups against the group with the lowest 25% of dietary fiber intake.
Reduced risk of dementia, especially with high soluble fiber
During the follow-up period, 670 people developed dementia requiring care.
The risk of developing dementia requiring care compared to the group with the lowest dietary fiber intake (bottom 25%) was 0.83 times higher in the second-lowest group
(25-50%), 0.81 times higher in the second-highest group (50-75%), and 0.81 times higher in the highest group (top 25%). The risk of developing dementia requiring nursing care tended
to decrease in those with higher dietary fiber intake. However, this association was only observed for dementia without a history of stroke.
There are two types of dietary fiber: soluble fiber, which dissolves in water, and insoluble fiber, which does not dissolve in water. Of the two, the soluble fiber was the one that showed
the greatest correlation.
Compared to the group with the lowest intake of soluble fiber (the bottom 25%), the risk of developing dementia requiring nursing care was 0.72 times higher in the second-lowest
group (25-50%), 0.77 times higher in the second-highest group (50-75%), and 0.72 times higher in the highest group (top 25%). The second-lowest group (25-50%) had a 0.72-fold
lower risk, the second-highest group had a 0.77-fold lower risk (50-75%), and the highest group (top 25%) had a 0.61-fold lower risk.
In addition, a similar association was found for potato intake, but not for vegetables or fruits.
Why dietary fiber reduces dementia
This study is the first in the world to show epidemiologically that the higher the intake of dietary fiber, the lower the risk of developing dementia requiring care.
So why do people who consume more dietary fiber have a lower risk of developing dementia? According to the research group, most of dementia (without a history of stroke) that was found to be associated with the study was considered to be Alzheimer’s disease, and “dietary fiber intake may reduce the risk of developing dementia by influencing the
composition of gut bacteria, improving neuroinflammation, and reducing other dementia risk factors. Dietary fiber may help prevent dementia.” Dietary fiber is said to be effective not only in preventing dementia, but also in suppressing the rapid increase in blood sugar levels after meals, lowering blood cholesterol levels, and preventing high blood pressure. Let’s diligently take it.
University of Tsukuba Press Release
People who consume more dietary fiber have a lower risk of developing dementia requiring nursing care.
Nutritional Neuroscience Dietary fiber intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study