Senile Dementia: Risk Halved Thanks to Folates

In the elderly, the risk of dementia may be influenced by blood folate (vitamin B9) levels, independently from other B vitamins and diet followed. In particular, those with higher folate concentrations show a 50% lower risk of dementia compared to those with lower amounts. These data come from a study conducted on the French population, where average folate consumption is quite low. The results suggest that supplementation with vitamin B9 may have a protective role in the brain when baseline folate levels in blood are low.

The research was conducted by scientists from the University of Bordeaux (France) and published in the journal Nutrients.

Folic Acid: A Vital Vitamin for Health

Folic acid is a vitamin (vitamin B9) involved in many essential functions in the human body, including DNA synthesis. The term folic acid refers to the chemical molecule present in vitamin supplements or used in the food industry to enrich some foods; while folates refer to a group of substances similar to folic acid found in some foods such as leafy green vegetables and citrus fruits. Folic acid and folates are essential for all body cells, especially those that need to reproduce or renew; therefore, folic acid requirements increase significantly during pregnancy.

Besides the periconceptional period, folic acid is also important for general health; deficiency causes a type of anemia called megaloblastic anemia and may increase homocysteine levels, an amino acid that at high concentrations is associated with cardiovascular disease and heart attack risk. B vitamins play a fundamental role in central nervous system function and seem promising for preventing dementia and Alzheimer’s disease. 

Epidemiological studies have found associations between high B vitamin intake and a lower risk of dementia and Alzheimer’s, particularly regarding folates. However, diet alone often does not provide sufficient folates, making supplementation with folic acid or fortified foods necessary. In some countries such as Canada, fortification of certain foods with folic acid is approved and mandatory. 

Currently, 78 countries worldwide have mandatory folic acid fortification programs, while many European Union member states have not implemented fortification. Among these is France, where the study was conducted, and where the population follows a diet poor in folates, resulting in low vitamin B9 blood levels. In other countries with similar conditions, such as Italy, the Netherlands, and the United Kingdom, studies have suggested that increased folic acid consumption may be linked to improved memory and reduced dementia symptoms in the elderly.

A Folate-Rich Diet Reduces Senile Dementia Risk by 50%

Led by Sophie Lefèvre-Arbogast, a researcher at the University of Bordeaux, scientists evaluated the ability of certain B vitamins obtained through diet to influence dementia risk in the French population. The team observed a strong association between folate consumption and long-term dementia risk; in particular, dementia risk was 50% lower in elderly individuals with the highest vitamin B9 blood levels compared to those with very low levels. 

No association was found for vitamins B6 and B12. While these results are similar to those of other studies, they contrast with some epidemiological studies conducted in countries with mandatory fortification. Researchers suggest this discrepancy indicates the protective brain effect of folates manifests in those normally deficient in the vitamin, but may be ineffective in subjects with higher baseline folate blood concentrations.

Research Details

During the study, researchers analyzed data from 1,321 elderly individuals without dementia. Interviews were conducted at the start to assess lifestyle and socio-demographic health characteristics, along with neuropsychological tests an_