Cognitive Decline

There are many causes of dementia and cognitive decline which, according to the Alzheimer’s Society, www.alzheimers.org.uk  affects 700,000 people in the UK and will rise to 1 million in 20 years.  The early symptoms of memory loss, confusion and problems with speech or understanding can be caused by many problems but the main ones are Alzheimer’s disease, vascular disease and a variety of degenerative neurological disorders. 

Sometimes a lack of nutrients is a factor especially vitamins B1 – thiamin and vitamin B12.  Additionally for many the risk of dementia is increased by poor lifestyle choices including smoking, lack of exercise, obesity and a diet lacking in fruit and vegetables, fish especially oily fish and high in undesirable fats the unsaturated fats from animal-based foods and trans fats from baked goods such as cakes and biscuits.  These latter fats may interact with the mineral copper from food or supplemental sources.

Copper

High in takes of copper from food and supplements has been associated with an increased rate of cognitive decline in elderly adults living in Chicago but only in those whose diet is rich in both saturated and trans fats.  In this study use of copper supplements providing approximately >1.0 mg/day long term in those aged 65 years and older may also have added to the observed decline.

The highest foods sources of copper are liver and shellfish with smaller amounts provided by nuts, seeds and wholegrains as well as some from the water supply.  In this US study total intake of copper was not associated with cognitive decline in those whose diets were low in these fats.  Furthermore there was no discernible effect of iron or zinc intake on cognitive decline.  The authors stress that this study is not conclusive and further research should be undertaken. 

Morris MC et al.  Dietary Copper and High Saturated and trans Fat Intakes Associated with Cognitive Decline.  Arch Neurol. 2006;63:1085-88

Folic Acid

High intakes of folic acid and dietary folate can mask the appearance of vitamin B12 deficiency.  This is because this vitamin B12 deficiency typically causes both anaemia and neurological changes and the anaemia but no the neurological features respond to treatment with folic acid.  If the diagnosis of vitamin B12 deficiency in someone with cognitive decline is not considered because they were not anaemic (as a result of folic acid supplementation) then the true underlying diagnosis of vitamin B12 deficiency might be delayed or missed.  Measurement of serum vitamin B12 and other tests of vitamin B12 utilisation are required.

Scientific Advisory Committee on Nutrition. Folate and Disease Prevention. TSO; London 2006

http://www.cks.library.nhs.uk/anaemia_macrocytic/view_whole_guidance