The recent calls for free or lower-cost dental care in New Zealand were well timed. It's World Oral Health Day this week in which people and governments around the world are encouraged to think about - and take action on - mouth health.

Our mouths are a mirror, in many ways, to our bodies. Oral health and general health are connected in some surprising and serious ways – looking after one can lead to much better health for the other.

The World Dental Federation says "the mouth cannot be isolated from the rest of the body". That's because many general health conditions increase the risk of oral diseases – diabetes can increase the risk of gum disease, for example.


And in some diseases, like diabetes, it's a two-way relationship: poor oral health can worsen the health of people with diabetes. Not only are people with diabetes more susceptible to gum disease, but according to the American Diabetes Association, serious gum disease may have the potential to affect blood glucose control and contribute to the progression of the condition. People with diabetes are generally less able to fight bacterial infections that might invade the gums.

Can poor oral health actually cause diseases? Maybe. There's an established link between gum disease and heart disease; it's thought gum disease increases a person's risk of heart disease by about 20 per cent – although exactly how this works is not yet clear. The theory is that inflammation in the gums – like chronic inflammation elsewhere in the body – could lead to atherosclerosis, the buildup of fatty plaque in the arteries.

The inflammation theory applies to other diseases, too. There are links between poor oral health and respiratory disease, gastrointestinal and pancreatic cancers and arthritis.

Short of diseases, a mouth in poor health can have a serious effect on our quality of life. Poor teeth often lead to poor diets – if your teeth hurt, you probably don't want to eat lots of crunchy healthy foods like fruit and veges – and poor diets, or course, lead to poor nutrition and poor health. Chronic pain from dental issues will naturally lower mood and could affect sufferers' social and professional lives.

All of this points to the need for good quality, consistent dental care for all Kiwis, throughout our lives. It won't have escaped your notice that there's a strong connection here with inequality. Those who are least likely to be able to afford dental care are also those who are at higher risk for non-communicable diseases (of which oral disease is a common one) and poorer health outcomes in general. And it's not just the most deprived who struggle with the cost of dental care.

That dental care is not part of our public health system for adults must be costing the country hugely, both in terms of money and in quality of life for many Kiwis. The NZ Labour Party adopted universal dental care as policy at its conference late last year; it will be fascinating to see if – and how – this is implemented. But it's really time it is.

Niki Bezzant is editor-at-large for Healthy Food Guide