Dementia Onset Hastened by
Calcium & Vitamin D Found in Dairy
Date: 14 May 07
 Calcium and vitamin D in dairy products may be helping to
cause brain damage and dementia in older men and women, new
research suggests.
Scientists believe too much calcium can narrow blood vessels
in the brain, leading to neural damage.
The effect may be compounded by vitamin D, which regulates
calcium retention and activity.
Researchers made the discovery after scanning the brains of
79 men and 153 women aged between 60 and 86.
All had at least a number of brain lesions - areas of tissue
damage.
They varied in size and included tiny ones often seen even
in healthy older people. But participants consuming the most
calcium and vitamin D were significantly more likely to have
a higher total volume of brain lesions.
Age, high blood pressure and other medical and mental
conditions, including depression, made no difference to the
results.
In earlier studies, the same US team found that individuals
who consumed high amounts of fatty dairy products had larger
numbers of brain lesions.
 However, fat intake in general was not a significant factor.
The researchers wanted to find out if a factor other than
fat caused the harmful effects of a high dairy diet.
The new findings, presented at the Experimental Biology
meeting in Washington DC, point to calcium, which exists in
abundance in dairy foods. Its regulator, vitamin D, is also
found in many dairy products as well as vitamin-fortified
foods such as margarine, breakfast cereal and bread.
Study leader Dr Martha Payne, from Duke University in
Durham, North Carolina, said: "At this point, we do not know
if high calcium and vitamin D intake are involved with the
causation of brain lesions, but the study provides support
to the growing number of researchers who are concerned about
the effects of too much calcium, particularly among older
adults, given the current emphasis on promoting high intakes
of calcium and vitamin D."
Her team is continuing to investigate possible ways in which
high levels of calcium and vitamin D might damage the brain.
The leading theory is that when too much calcium is absorbed
into blood vessel walls it produces bone-like deposits. This
calcification may narrow the blood vessels and make them
less flexible, reducing the blood flow through them.
In the brain, neurons could be deprived of blood and die,
causing the lesions that increase the risk of cognitive
impairment, dementia, depression and stroke. |
