Where both twins had the disease, there was an average of 3.66 years difference in age at onset between 25 sets of identical twins, and 8.12 years difference between 20 sets of fraternal (dizygotic) twins, suggesting genes had a role in determining when Alzheimer's was seen.

BBC: NEWS | Health | Alzheimer's risk 'is 80% genetic'

In a subgroup of families who had identical chromosome markers, those with no mutations in the gene developed symptoms at an average age of about 61, those with a single abnormal copy of parkin at around age 50, and those who inherited two mutated copies had onset at around age 36.

BBC: NEWS | Health | Gene 'predicts' Parkinson's onset

Magazines were one of the earliest mechanisms for social grouping, and before the onset of the digital age, publishers were very good at building and monetizing highly valuable networks of similar people built around different content verticals.

FORBES: For Magazines, The Digital Future Lies Beyond The iPad