Calamari oil contains omega 3 which is of course beneficial to anyone. But it's best consumed fresh in fish or seafood than in pills and there is no conclusive evidence that it helps once dementia has developed. http://en.m.wikipedia.org/wiki/Omega-3_oil
It doesn't seem to be anything other than omega 3 but in a more concentrated form,
from an article in the Daily Mail
"A month’s supply of 30, 1,000mg Calamari Gold capsules costs £34.99 from Holland and Barrett. An equivalent supply of cod liver oil capsules costs around £2.25."
Or £3.50 for 90 tablets at Asda, I think I'll stick with the Asda ones (other supermarkets are available).
I saw that ad today - 'Dementia? Forget it!'
'....keeps your brain young and active...'
Quite frankly I feel like reporting it to the Advertising Standards Authority. It clearly implies that if you take it, you will not get dementia. If there had been any such proven breakthrough I am sure we would not need an ad to tell us about it.