Dementia causes a person to become progressively forgetful and confused with time – a process which cannot be medically cured or slowed down. Prevention is therefore key, and evidence suggests caution is warranted when taking certain supplements. Folic acid, which is widely taken by pregnant women, may best be avoided by older people deficient in vitamin B12, studies suggest.
The subject of brain decline has long been a point of interest for researchers, particularly in light of the growing burden of dementia.
The body uses folate for red blood cell formation and healthy cell function and growth, according to the Mayo Clinic.
It occurs naturally in dark green leafy vegetables, nuts, beans and peas, as well as fruit such as lemons, oranges, bananas, strawberries and melons.
Preliminary research has suggested dementia and Alzheimer’s disease could be linked to low folate levels and high homocysteine levels, which has prompted a close examination of the link between the vitamin and the disease.
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It is now known that folic acid affects several bodily functions including mood and cognitive functions, especially in older people.
A lack of folate could therefore affect brain function and nerve signalling, potentially raising the risk of dementia and death.
Taking the right amount of folic acid, however, is important to protect against loss of brain function.
An excess folic acid intake could conversely accelerate the mental decline in people with low vitamin B12 levels.
In one study on people over the age of 60, published in the American Journal of Clinical Nutrition, researchers discovered a link between high levels of folate linked and mental decline in people with low levels of low vitamin B12.
This link was not apparent in people with normal levels of vitamin B12, however.
Another study, published in the journal of Alzheimer’s Disease, found that people with high levels of folate and low vitamin B12 levels were 3.5 times more likely to experience loss of brain function, compared to those with normal blood levels.
The researchers noted: “Folate fortification of food aims to reduce the number of babies born with neural tube defects but has been associated with cognitive impairment when vitamin B12 levels are deficient.
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“Given the prevalence of low vitamin B12 levels among the elderly, and the global deployment of food fortification programs, investigations of the associations between cognitive impairment vitamin B12 and folate are needed.”
Pathways Health explains that folic acid, a B vitamin used by the body to manufacture DNA, is necessary for rapid cell division and organ and tissue formation in developing babies.
The recommended daily intake of folate for adults is 400 micrograms, which can be sourced from fortified foods like breakfast cereals, bread, rice, pasta and orange juice.