&quot;That said, the prevalance of diseases like Alzheimer&#x27;s might be a fairly modern aberration, perhaps owing to lifestyle, environmental, and dietary factors.&quot;<p>Also somewhat owing to the recognition of Alzheimer&#x27;s as a disease state (coincident with amyloid beta plaques) rather than just part of &quot;getting old&quot;.  The difference between &quot;more prevalent&quot; and &quot;better identified&quot; is difficult to determine.