Drinking warm lemon water in the mornings has been promoted as a way to help digestion.
But doing so without taking precautions around dental health could leave a sour taste in the mouth.
People having the drinks – lemon juice squeezed into a glass of water - are being advised to drink through straws or flush afterwards with plain water to lessen the exposure of teeth to acidic lemon juice.
Lemon juice has a pH of around 2. Pure water has a neutral pH of 7 while battery acid a pH of 1.
Naturopath Erin O'Hara said the use of lemon water, especially in cleansing routines, has "been around a long, long time".
"Usually you'd want to have lemon juice with water to start to stimulate digestion," said O'Hara, who has a Bachelor of Science in physiology and a Bachelor of Natural Medicine.
"It helps produce saliva production in the mouth. Saliva helps with the breakdown of food. Lemon juice stimulates digestive function and improves liver function. It is a really great cleanse technique to have in the morning with warm water to help stimulate bowel function and improve elimination."
But over the past year there had been a highlighting of concerns around potential damage to tooth enamel from the practice if precautions were not taken, she said.
O'Hara, owner of the Golden Yogi studios and wellness clinic in Auckland suburb Takapuna, advised her clients to have lemon water through a straw "so it doesn't get too much on your teeth.
"Or having a lemon water and then having some water to follow up after it because of the acidity of the lemon juice - so you [have] not got the acidity sitting on your teeth."
O'Hara said the caution around dental health was especially relevant for people who drank lemon water throughout the day.
"I usually use it more as a cleansing tool. So you'd have either half or a full lemon squeezed (into a glass with 250ml of) warm water in the morning - you wouldn't sip lemon water all day."
She did not have lemon water on a daily basis.
But O'Hara said cautions around dental health also applied to sugar and sugary drinks.
"[If] you don't have anything (to rinse your mouth) after it, then the sugar just sits on the teeth."
Dr Erin Mahoney, a paediatric dentist, said the low pH level of lemon juice meant it could cause enamel loss. "Some people will not show significant signs of erosion as they may have protective factors in their saliva that may reduce their risk of tooth erosion."
Enamel erosion can result in teeth appearing yellower because underlying dentin, yellower than enamel, is exposed. It can also cause tooth sensitivity.
Chewing sugar-free gum after drinking lemon water has been suggested, to produce more saliva to help neutralise acidity in the mouth.
Mahoney said: "Chewing sugar-free gum and use of [a] straw is a good idea.
"Also making sure you don't swish the lemon juice around your mouth and just drink directly will reduce the time in your mouth and reduce exposure time to the acidic beverage."
"If you regularly consume lemon products, then it's a good idea to see your dentist regularly for them to monitor for any signs of dental erosion and provide ongoing advice," she said.