A recent ARC doctoral dissertation shows that the right levels of vitamin B12 and folate can reduce the risk of Alzheimer’s disease.
Older people at risk of Alzheimer’s disease should have their levels of vitamin B12, folate, and homocysteine checked regularly. Treatment of high levels of homocysteine—which are often a consequence of B12 or folate deficiencies—can lower the risk of the disease. This is the main message of Babak Hooshmand’s doctoral dissertation, “The impact of homocysteine and B vitamins on Alzheimer’s disease, cognitive performance and structural brain changes.” 
Dr. Hooshmand chose to focus on vitamin B deficiency and Alzheimer’s disease in older people because low B-vitamin status is a common condition in elderly people, and because results from basic science studies suggested there might be a link between B vitamins and Alzheimer’s disease. However, previous population-based studies on the topic were small, did not have a long follow-up duration, and did not include several important factors relevant to the association between B-vitamins and Alzheimer’s disease.
His dissertation presented the results of four important studies. The first included 274 people aged 65 to 79 years from the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study who were cognitively intact at the beginning of the study. These people were followed for seven years, when they were re-examined to diagnose those who developed Alzheimer’s disease. The study showed that holotranscobalamin, the active part of vitamin B12, is associated with reduced risk of Alzheimer’s disease, and this protective effect became even more important with increasing age.
The second study showed that holotranscobalamin reduced the risk of poor cognition, whereas homocysteine increased the risk. Interestingly, these effects were observed even in people who did not develop Alzheimer’s disease during the seven years of follow-up. In the third study, which included people 85 years and older, Dr. Hooshmand found that homocysteine strongly contributed to increased Alzheimer’s type pathology, particularly the burden of neurofibrillary tangles in the brain.

– This thesis clearly shows the impact of right levels of vitamin B12 and folate in reducing the risk of Alzheimer’s disease and suggests some important pathways for the observed associations, says Dr. Hooshmand.
The results of the fourth study in the dissertation showed that higher levels of B12 were related to less loss of brain volume in 501 participants from the Swedish National study of Aging and Care in Kungsholmen (SNAC-K).
According to Dr. Hooshmand, the third study was the most interesting one, because it showed for the first time that homocysteine is directly associated with the pathology of Alzheimer’s disease over 10 years.
Dr. Hooshmand is a medical doctor currently completing his specialist training in neurology in Germany. He would also like to continue doing more research on the topic.
– I’m very much interested in basic science as well as clinical neurology. Good knowledge in basic science, epidemiology, statistics, and medicine makes it easier to pursue the kind of research I’m interested in. It’s quite challenging, but I like doing it.
Babak Hooshmand used data from the following studies: Studies I and II—Cardiovascular Risk Factors, Aging and Dementia (CAIDE); Study III—Vantaa 85+, a neuropathological study; and Study IV—the Swedish National study of Aging and Care in Kungsholmen (SNAC-K).
The photo shows food products containing vitamin B12.