Healthy ageing

When we think of healthy ageing, we often associate it with life expectancy. On average, Kiwis now live into their early 80s, about 80.3 years for men and 83.9 years for women, placing New Zealand among the top 30 countries globally. 

However, a more important measure is our Health-Adjusted Life Expectancy (HALE). Calculated by the World Health Organisation (WHO), this is the number of years people in a particular country can expect to spend in good health. By this standard, we fare much worse. Although the New Zealand HALE measure has improved over the past decades to 70 years, it still means many of us will spend the last 10 to 20 years of our lives in poor health.

Much of this gap is due to non-communicable diseases (NCDs), often called chronic or preventable diseases. These conditions do not spread from person to person but develop gradually over time, influenced by lifestyle and environmental factors and include heart disease, diabetes, cancers, and dementia.

Today, NCDs are the leading cause of death worldwide and according to The Global Burden of Disease Study 2021 (a major international health study analysing the causes of illness and death) the leading causes of death in New Zealand are cardiovascular diseases, cancers, diabetes and kidney diseases, respiratory illnesses, and neurological disorders. The study found that more than a third of New Zealanders’ illnesses are linked directly to lifestyle-related risk factors with the top five contributing factors being high body weight (BMI), smoking, high blood sugar, high blood pressure, and poor diet. 

NCDs are also closely linked to ageing because many develop slowly over a lifetime. As we age, our bodies become less resilient, our cells take longer to repair, immune function declines, and the effects of long-term wear and tear become more evident.

Moreover, the longer we live, the more exposure we have to risk factors such as poor diet, lack of exercise, smoking, and environmental pollutants. Even conditions that may not seem directly related to ageing, such as type 2 diabetes, become more likely as our body’s ability to regulate blood sugar declines over time.

Neurological disorders such as Alzheimer’s and Parkinson’s disease also rise significantly with age. Between ages 60 and 65, about three per cent of people experience mild cognitive impairment, but by age 85, dementia prevalence reaches about 22 per cent, and by age 90 it affects more than one-third of people.

Medical advances have successfully increased our life expectancy by improving treatments for diseases and injuries, which previously would have been fatal, allowing people to live longer than ever before. Gone are the days of dying from simple infections, but this also means more of us are reaching ages when chronic diseases become our primary health concern. Now, the challenge isn’t just living longer, it’s ensuring those additional years are spent in good health. Preventing and managing chronic illnesses early in life is essential to closing the gap between average life expectancy and our healthy years.

The good news is that many chronic diseases are strongly influenced by lifestyle choices and by making positive changes, we can significantly improve our long-term health and live healthier for longer.