Absolutely not. According to George Deeb of Entrepreneur magazine, age is just a number for entrepreneurs, and the stereotype of Mark Zuckerberg as the prototypical young founder is missing the fact that the average age of entrepreneurs is 40, and people over 55 are more likely to launch high growth startups.
As a case study, Paul English of Kayak was in his late 30's when he co-founded Kayak in 2004 - and Kayak was acquired by Priceline for $1.8 Billion in 2012. As of 2015, Paul is working on his next startup. According to Scott Kirsnher in this Boston Globe article, the average age of the founding team of OnShape (led by CEO Jon Hirschtick) is over 50.
Young entrepreneurs have an edge over older entrepreneurs in that they have more energy and stamina, need less sleep, and generally have less financial and other obligations - this affords them great flexibility in how they are able to work, and how they are able to go with no or minimal pay for extended periods of time.
Older entrepreneurs may have other considerations from a financial and time commitment standpoint, but they also have more life experience, and they have had more time to build a solid network to draw investors, advisors, co-founders and employees from.
If you are a more mature entrepreneur and are passionate about solving a problem and having impact, go for it - you may not be able to go without sleep for 5 days in a row, but you also have the advantage of more experience and a better support system that will help you bypass common mistakes and succeed in your startup journey.