The number of centenarians around the world rose from 151,000 in 2000 to 573,000 in 2021. People are living longer, and more people will reach the age of 100 in the years to come.
“Centenarians exemplify successful ageing, often experiencing fewer chronic diseases and maintaining independence in daily life well into their 90s. While genetics contribute to longevity, modifiable factors account for more than 60% of successful aging,” said researchers Zhaoli Dai-Keller, Honorary Senior Lecturer, School of Pharmacy, University of Sydney; Nutritional epidemiologist and Lecturer, School of Population Health, UNSW Sydney.
Dr. Dai-Keller and Perminder Sachdev, Scientia Professor of Neuropsychiatry, Centre for Healthy Brain Ageing, School of Psychiatry, UNSW Sydney, reviewed lifestyle and health habits of centenarians and near-centenarians (those aged 95-99) worldwide.
They found four key factors that contribute to extreme longevity:
- A diverse diet with controlled salt intake
Centenarians and near-centenarians typically had a balanced and diverse diet. The researchers found, on average, they consumed between 57% and 65% of their energy intake from carbohydrates, 12% to 32% from protein, and 27% to 31% from fat. Their diets included staple foods (such as rice and wheat), fruits, vegetables, and protein-rich foods like poultry, fish and legumes, with moderate red meat consumption.
Most centenarians also preferred a low-salt diet. Only one study in the review measured the mean daily sodium intake, finding 1.6 grams, this was within the World Health Organization’s recommendation of less than 2g of sodium per day (equivalent to about 5g of salt). The traditional Okinawan diet, known for its consumption by Japanese centenarians on Okinawa Island, contains an estimated 1.1g of sodium.
“Higher salt intake (those who preferred salty food or added extra salt to meals) had a 3.6-fold increased risk of physical function impairment compared to those without a preference for salt,” said the two researchers.
- Lower medication use
Centenarians are not free from chronic conditions but typically develop them much later than average adults. More than half of the people in our review experienced common issues such as hypertension (high blood pressure), dementia, or cognitive impairment.
“We found people in our review took an average of 4.6 medications. The most frequently used medications included blood pressure medications and drugs for heart disease. This is similar to the results of a large health register-based study in Spain, which found centenarians took an average of 4.9 medications. Non-centenarians in this study took 6.7 medications on average.”
“Polypharmacy is often defined as taking five or more medications simultaneously, and is common in older adults. Inappropriate polypharmacy is associated with increased risks of adverse events such as falls, cognitive impairment and hospitalisation, due to harmful drug interactions.”
- A good night’s sleep
Sleep quality and quantity affect the immune system, stress hormones, and cardiometabolic functions such as obesity, high blood pressure, and diabetes.
“Good sleep is associated with extended years of good health and reduced risks of chronic diseases. In our review, 68% of the centenarians were satisfied with their sleep quality. In a survey of adults’ sleep satisfaction in 13 countries in 2020, sleep satisfaction ranged from 29% to 67%,” the two researchers.
“The optimal sleep duration is between seven and eight hours per night. Tips to achieving better sleep include keeping a regular sleep routine, creating a restful environment, exercising regularly and managing stress.”
- Where you live
“More than 75% of the centenarians and near-centenarians in our review lived in rural areas. This is a pattern reflected in “blue zones”, areas known for high concentrations of centenarians, such as Okinawa in Japan, Sardinia in Italy, the Nicoya Peninsula in Costa Rica, and Ikaria in Greece.
“This may be partly related to the connection between nature and health and wellbeing. For example, exposure to green space has been associated with lower stress, depression, blood pressure, type 2 diabetes and heart disease, potentially increasing life expectancy.”