Experts have claimed that older people who lack a key B vitamin could have triple the chance of developing dementia.
Folate, which is also known as vitamin B9, is found in a variety of foods, including leafy green vegetables, dried beans and peas. It is sometimes added to products like bread or breakfast cereals in the form of folic acid.
Now a study published online in the Journal of Neurology Neurosurgery and Psychiatry has discovered there is a higher risk of dementia among those lacking folate.
Researchers tracked the development of dementia in 518 people over 2.4 years from 2001 to 2003.
All participants were over the age of 65 and lived in one rural and one urban area in the south of Korea.
Tests were taken to assess levels of folate, vitamin B12, and the protein homocysteine, and the researchers found that people who were folate deficient to begin with were almost 3.5 times more likely to develop dementia.
A spokeswoman for the Alzheimer's Society said: "This latest study is one further example of why it is so crucial for people to lead a healthy lifestyle with a balanced diet rich in B vitamins and antioxidants.
"The findings add weight to growing evidence about the important role that dietary factors can play in preventing dementia."
"I think that you can do everything right to help prevent treatable forms of dementia such as vitamin deficiencies but it will not help those that develop irreversible progressive forms of dementia such as Alzheimer's disease" - Theresa Mura-Regina, Saskatchewan, Canada