''It shows we were right,'' he said yesterday.
The study, whose lead author is Associate Prof David McBride, of the university's preventive and social medicine department, also found a doubling of the risk of mortality from cancers of the head and neck, as well as an increase in oral cancers of the pharynx and larynx, among Vietnam veterans compared with the general population.
This is the first comprehensive study to produce ''hard data'' showing adverse health effects on New Zealand veterans from their service in Vietnam, researchers say. And the study will shortly appear in the international journal BMJ Open.
Mr Gordon (67) said for about 40 years it was officially denied Agent Orange was having any adverse effect on the health of Kiwi veterans.
Agent Orange was used extensively in Vietnam as a herbicide and defoliant, partly to make it easier to spot enemy troop and guerrilla movements by removing some of the lush jungle cover.
In 2004, then prime minister Helen Clark's government apologised to Vietnam War veterans exposed to Agent Orange or other toxic defoliants, after a health select committee inquiry into the use of the chemicals.
Mr Gordon served in Vietnam for 13 months, mainly in 1967, as a truck driver and infantryman with 161 Battery.
He welcomed the Otago study's findings, but said that despite earlier high-level assurances, some veterans were still losing a ''paper war'' over their rightful entitlement to support.
He lives in Owaka but has been staying at the Montecillo War Veterans Home and Hospital after a recent operation in Dunedin Hospital to counter a spinal injury put down to jumping out of helicopters in Vietnam carrying heavy gear, including a pack and firearm.
The Otago study had come ''too late for a lot of people'', who had died, ''but it's not too late for some of the families'', who now needed more support.
In some families, birth defects and related significant health problems had been emerging in several generations of the veterans' descendants, and there had been problems in his own extended family. He had also had cancer, including of the bowel.
Prof McBride said he wanted the Otago study to be of active practical use, and not be left sitting on a shelf.
The study showed there had been some adverse health effects on Vietnam veterans, and there was a moral obligation for New Zealand to ensure those veterans were well supported.
Good support was provided for Vietnam veterans through the Montecillo facility in Dunedin, but more backing was needed elsewhere in the country, he said in an interview.
The RSA yesterday welcomed publication of the Otago study and said it vindicated claims about the adverse health effects of service in Vietnam.
RSA national president Don McIver thanked Prof McBride and his colleagues for ''this important work'', and noted the study had been commissioned by the War Pensions Advisory Board, of which the RSA is a member.
Veterans' health will also be on the agenda at a two-day conference in Dunedin starting today, organised by the Otago University researchers focusing on the theme of ''Health of Veterans, Serving Personnel and their Families''.
