No, not at all. There are groups of people who live their whole lives without any carbs in perfect health.

Jean, is there any research studies that show this?

It is basic human biochemistry, actually. The body does not need carbohydrates, since glucose can be made from dietary protein. The Inuit survived with little or no significant carbohydrates in their diet for thousands of years.

There are many individuals who eat close to zero carbohydrates here: http://www.rawpaleodietforum.com/carnivorous-zero-carb-approach/

Also read http://www.jbc.org/content/87/3/651.full.pdf, about Vilhjalmur Stefansson, http://en.wikipedia.org/wiki/Vilhjalmur_Stefansson#Low-carbohydrate_diet_of_meat_and_fish. Meat including organs and animal fat will supply all necessary nutrition, sans spring or mineral water and mineral salt.

The phrasing of the question makes it difficult to give the answer that will satisfy the intent of the question.

Do we 'need' carbs? No.

Are carbs beneficial to gaining and maintaining optimal human health? Possibly/probably.

I understand. Well, what are "carbs" in the abstract, but an energy source? Do we need a source of energy? Yes. But we know that fat can be energy, and protein can stand in for glucose, in place of dietary carbs. So again, the answer is no. Now, if you are asking whether we need other things in the foods that happen to be higher in carbohydrates, that is a different question. But I would say that everything a human needs for health is available in meat from ruminants eating a diet that is close to their evolutionary diet, or other animals eating their evolutionary diet, as well as mineral or spring water, non-polluted air, and plenty of sunlight. I cheated of course by using the word "health." I mean, if I am starving to death a bowl of sugar is very healthy, it will keep me alive. But here we are talking about what humans have evolved to eat. Our bodies appear to be adapted so that we can "eat carbs", which in paleolithic times would have been leafy green vegetation and fruits, for the most part. Some people find that they need such carbohydrate sources to remain healthy, while others (such as myself) find that they do fine not eating any carbs (or nearly none, I do eat liver, eggs, some seafood that is higher in carbs).