Put some meat in your diet, folks, lest you end up voting liberal:

Vegans and vegetarians are the most likely to be deficient because the best sources of the vitamin are meat, particularly liver, milk and fish. Vitamin B12 deficiency can also cause anaemia and inflammation of the nervous system. Yeast extracts are one of the few vegetarian foods which provide good levels of the vitamin.

The link was discovered by Oxford University scientists who used memory tests, physical checks and brain scans to examine 107 people between the ages of 61 and 87.

When the volunteers were retested five years later the medics found those with the lowest levels of vitamin B12 were also the most likely to have brain shrinkage. It confirms earlier research showing a link between brain atrophy and low levels of B12.

There are other hazards to a strict vegan diet. I am guessing the parents of this Scotland child have already suffered from a shrunken brain:

A 12-YEAR-OLD girl in Scotland brought up by her parents on a strict vegan diet has been admitted to hospital with a degenerative bone condition said to have left her with the spine of an 80-year-old woman.

Doctors are under pressure to report the couple to police and social workers amid concerns that her health and welfare may have been neglected in pursuit of their dietary beliefs.

The girl, who has been fed on a strict meat and dairy-free diet from birth, is said to have a severe form of rickets and to have suffered a number of fractured bones.

That does it for me. Time for a bacon sandwich.