The Center for Retirement Research at Boston College has issued a brief report on How Do Job Skills That Decline With Age Affect White-Collar Workers? It's far from definitive but the authors' conclusion is that white collar jobs do require skills that decline with age and some white collar jobs are more susceptible to this than others. Two examples would be airline pilot and photographer.
The authors try to scale jobs based upon susceptibility to age-related loss of job skills. Here's a couple of charts from the report: