From the Shambhala Sun Space article by Monk Thanissaro Bhikkhu

http://www.shambhalasun.com/sunspace/?p=22527

1) “Life is suffering.”

This is one of the Big Lies of Buddhism—a claim assumed to be true simply because it is repeated so often—both in popular books and academic books. The phrase “Life is suffering” is supposed to be a summary of the Buddha’s first noble truth, but the first noble truth simply lists the things in life that constitute suffering: “Birth is stressful, aging is stressful, death is stressful; sorrow, lamentation, pain, distress, & despair are stressful; association with the unbeloved is stressful, separation from the loved is stressful, not getting what is wanted is stressful. In short, the five clinging-aggregates are stressful.” (Quotation from Samyutta Nikaya, The Grouped Discourses of the Buddha, 56.11)
Life, you’ll notice, isn’t on the list.

The other noble truths go on to show that there’s more to life than just suffering: There’s the origination of suffering, the cessation of suffering, and the path of practice leading to the cessation of suffering as well.
I know he is of the Theravada tradition and he is quoting solely from that canon. So. Where do we get that first noble truth is stated as such? "Life is Suffering". :?: