An article from University of Oslo

In Norway, 70 000 persons over the age of 65 suffer from dementia. (Photo illustration: Colourbox)

Vitamin B impedes development of Alzheimer’s

A recent study shows that supply of Vitamin B reduces cerebral atrophy. For the first time, a method has been found to protect those areas of the brain that are damaged by Alzheimer’s disease.

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University of Oslo

The University of Oslo is Norway's leading institution of research and higher education.

Do you know someone who has started to search for words or speak slowly? Or someone who suddenly has problems in finding their way about, remembering simple things or learning something new?

This could be an indication of mild cognitive impairment (MCI). MCI is an incipient stage of dementia. Not all those who experience MCI will develop dementia, but it is an early and clear signal.

The brain shrinks

If you develop Alzheimer’s, the cerebral cortex is reduced and the ventricles inside your brain grow larger. The brain shrinks; this is referred to as cerebral atrophy.

Cerebral atrophy progresses twice as fast in persons with MCI than in a normal, healthy sixty-year-old. In persons with fully developed Alzheimer’s, cerebral atrophy progresses seven times as quickly.

B12 had the best effect

The research is based on previous findings showing that vitamin B can retard cerebral atrophy of the areas attacked by Alzheimer’s.

"We therefore believe that the most important effect was produced by B-12. Most of the participants had sufficient amounts of the B vitamin folate," says Helga Refsum, Professor of Molecular Nutrition at the University of Oslo.

Half of the test persons had a high level of homocysteine. The doses of B12 used were higher than can be supplied through regular intake of food. The study showed a considerable reduction in cerebral atrophy in the group that had a lot of homocysteine.

The degree of cerebral atrophy was measured prior to and after the two-year test period.

Linkage between amino acids and MCI

Prior research has shown that there is a clear linkage between excessive levels of the amino acid homocysteine and MCI. Homocysteine is found in the blood and the cells.

The researcher believes that homocysteine causes increased formation of neurofibrillary tangles. These tangles are formed when the fibres inside the brain cells intertwine. The tangles prevent communication inside the brain, and finally these brain cells die.

"If you have an elevated level of homocysteine, a lack of the vitamin B types B12 or folate could be the cause. The theory is thus that more vitamin B reduces the formation of tangles," says Refsum.

Cognitive ability was tested throughout the study. Statistical analysis showed that the reduction in cerebral atrophy limited memory loss and improved the daily life of the test persons. However, this occurred only in those with high homocysteine levels, i.e. somewhat poor vitamin B status. Test persons with low levels of homocysteine did not experience the same positive effect.

Poor folate status in Norway

The study was conducted in the UK and is a collaboration between the University of Oxford and the University of Oslo. Refsum explains:

"In Norway, our folate status is significantly poorer. The reason is that in the UK, folate is added to a number of foods to prevent spina bifida. This is a controversial topic, since it can give a slight increase in the risk of cancer. What should we choose? We would therefore need to take a closer look at folate if we were to undertake the same study in Norway."

Positive participants

The VITACOG (Vitamins and Cognition) study included 270 persons over 70 with MCI. This group was chosen because they still functioned adequately in daily life and their brains were not yet seriously damaged. In fully developed Alzheimer’s the brain is permanently damaged and there is no cure. Alzheimer’s must thus be prevented at the earliest possible stage.

The participants in the study took a positive view of the project and experienced very few adverse effects. No differences in cancer prevalence between the test groups were registered.

Reduced absorption of vitamin B in old age

An insufficient level of vitamin B may stem from a poor diet, not enough fruit and vegetables, high alcohol consumption and certain types of medication. In addition, our ability to absorb vitamin B is reduced as we grow older. Vegetarians may have an especially low intake of vitamin B and need to supplement their diet.

"If you have problems absorbing vitamin B, you cannot counteract this by increasing the intake of certain types of food. Instead, you will need to use supplements and in some cases even injections," Refsum explains.

Promising results

Refsum hopes that the study may lead to research in other areas in which we are aware of risk factors that may cause Alzheimer’s. These include hypertension, diabetes, poor diet and physical inactivity.

"That way, we may help prevent and slow the advance of Alzheimer’s. Today, treatment starts too late, at a stage when the patients are already suffering from severe amnesia," she says.

"This is only one study. Even though it is extraordinarily convincing, other corresponding studies must be undertaken. The results are really promising, and ignite the hope that the struggle against Alzheimer’s has not been lost," Refsum concludes.

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