After the debate, Mr Wallace said the figures saddened him.
"But what I'm saying is we need to be aware that the homosexual lifestyle carries these problems and ... normalising the lifestyle by the attribution of marriage, for instance, has to be considered in what it does encouraging people into it," he said.
Mr Wallace said legalising same-sex marriage in other countries had not reduced risk factors for gay people.
"Where gay marriage has been introduced, or civil unions, it hasn't changed the level of suicide," he said.
"We have to accept the unfortunate levels of suicide, the unfortunate levels of excessive drug use (are) because of the nature of the lifestyle.
"I am very sorry for that. My heart goes out to those people. But it is a fact."
Senator Milne said discrimination in laws such as the Marriage Act was a contributor to any health concerns.
"What I know is that the mental health issues for young gay people particularly are certainly increased when discrimination occurs," she told reporters.
There was little love lost between Mr Wallace and Senator Milne during the debate.
Senator Milne accused the ACL of homophobia and said Christians should be more concerned with poverty than homosexuality.
She said with bills before the federal parliament and Tasmania's lower house last week passing a same-sex marriage bill, change was inevitable.
Mr Wallace accused the Greens of demonising churches with "hate language" and caring more for trees than children.
He described gay activism as "bullying" and said a climate had been created for "legislation by fatigue".
Tasmanian marriage equality advocates said the ACL was using outdated figures from a survey of obituaries in San Francisco newspapers at the height of the AIDS crisis.
"Yes, there are health problems in parts of the gay and lesbian community, but they are caused by the prejudice of people like Mr Wallace and the discriminatory laws he defends," Tasmanian Gay and Lesbian Rights Group spokesman Rodney Croome said in a statement.
"Mr Wallace's offensive remarks show how desperate he has become, and they effectively deal the Australian Christian Lobby out of the marriage equality debate."
Mr Croome said ACL representatives had previously linked gay equality to Nazis, paedophiles and the stolen generations.
"The quoting of irrelevant and biased studies to stigmatise gay Australians is a low and desperate tactic that diminishes Mr Wallace and his cause," Mr Croome said.
- AAP