With this year's school ball season approaching, young people are being encouraged to be careful when drinking alcohol.
"Evidence shows that drinking alcohol at a young age can cause harm to the developing brain because a person's brain is still developing until the age of 25," Whanganui District Health Board health promotion officer Chester Penaflor said.
"Drinking alcohol at this age may result in developing learning difficulties, memory problems, mental health issues and other problems later in life such as alcohol abuse and alcohol dependency problems."
Mr Penaflor supported the national Health Promotion Agency's message that the safest option for people under 18 was to not drink.
The message is also endorsed by the Cancer Society, which says evidence shows alcohol use can cause cancer.
According to the Ministry of Health, the rate of "hazardous drinking" among drinkers aged 15-17 in 2011-2012 was 21 per cent, Mr Penaflor said.
"One in five, or 19 per cent, of New Zealanders aged 15 or older who drank alcohol in the past year now have a potentially hazardous drinking pattern."
He said the relationship between young people and alcohol was strongly influenced by New Zealand's drinking culture, which normalised heavy alcohol use.
There were things adults could do to help reduce the impact alcohol had on teenagers, however.
"We know that what we do as parents, how we communicate our expectations and whether we supply alcohol does influence our children's choices.
"If you do decide to provide alcohol, make sure that they are actively supervised, substantial food is offered, low or no alcohol beverages are available and transportation is arranged.
"As parents, we all want what's best for our children. It's time to break the cycle. No alcohol for under-18s is the safest choice."
Mr Penaflor is able to talk about the dangers of underage drinking to interested parties. Contact him on 348 3150.