The idea that aluminium causes dementia is alive and well on the internet, but there is no evidence that this is the case. The excellent Snopes
http://www.snopes.com/cooking-with-aluminum-foil-puts-you-at-risk-for-alzheimers/ looks at the evidence and says 'false'.
The cost of an aluminium pan is a lot cheaper than Ti, and has been pointed out, spreads heat better (Ti is weird like that). In terms of weight, even double has to be seen in context of the whole, and of course wont be any difference in terms of bulk. Choose whatever you like to cook in/eat out of - there is plastic, aluminium, steel or Ti (Kirsten H has a great pros and cons of each here:
https://www.backpacker.com/gear/cookware-comparison ), and its for you to judge which is most suitable for you.
But your list was:
3 piece for knife and spoon set
insulated cups
bowls
plates
If you just replaced one of those each over what you've already got (say plastic or aluminium) with Ti, then you possibly talking £13 + £33 (the cup) + £19 + £15. Thats about £75 (if you shop around, etc) per
person. Yes, you could get rid of the aluminium if that worries you, but pretty much none of those have even a notional risk. And yes, you'll save some weight, but its perhaps 500g at most. If you have the Lifeventure plastic insulated mug and you swap it out with their Ti version, then your chucking a £9 mug with one for £33 - and saving just
15g.
Scale that up to a family of 4, and thats a lot of money. For not that much difference in weight. If your worried about cooking in aluminium, then go for steel or Ti (£45 for the set from Alpkit). Thats fine. But the family wont care much if they are eating off tupperware, a cheap stainless steal bowl or Ti.
If your worried about weight, think how much the cost of replacing all that kit is, and what else you could do with that cash that would make a bigger difference. Sleeping bag is the obvious one, then tent and sleeping mat. Ti is not low hanging fruit - more of the 80/20 rule.
On the other hand, if there is a deal and you are looking for a new cooking set anyway, then Ti can make a lot of sense, because its something you tend to buy once. Thats how I justify buying my stuff. And because I like shiny things...
