It’s not uncommon to look at people who live beyond 90 (or even 100) and wonder: How do they pull it off? In an attempt to answer that question, researchers at the University of California gathered data on people aged 90 and up for over a decade. Some of their findings, discussed in the WebMD article “Surprising Secrets of ‘Super Agers’” (September 2015), may surprise you.

Perhaps the biggest revelation is that some of the conventional risk factors for dementia—high blood pressure and high cholesterol—don’t apply to people in their 90s. In fact, these generally harmful conditions (or perhaps the medications being taken for them) appear to have a protective effect against Alzheimer’s for nonagenarians. With hypertension, timing is everything: If you develop high blood pressure in your late 80s or 90s, it appears to have a protective effect; if the onset is any earlier, in your 60s say, there is no such effect.

Another negative that becomes something of a positive after a certain age is weight. Being overweight isn’t good for you when you’re young, but it becomes a protective factor for longevity as you age through your 70s, 80s and 90s. Researchers theorize that the ability to gain or at least maintain weight may be a sign of robustness; being frail increases your risk level in certain areas, including a 50 percent increase in mortality.

Despite these counter-intuitive findings, most of the usual health rules apply in the quest for longevity. To increase your chance of becoming a super ager, simply make sure your healthy diet contains plenty of fruits and vegetables, get moving for at least 15 but hopefully 45 minutes every day (walking counts) and exercise your brain by interacting with others.

Scientific studies are great in the abstract, but on a more anecdotal level, how do some of the oldest people in the world explain their longevity? A recent Mental Floss article, “8 Ways to Live a Really Long Time, According to the Oldest People Ever,” (March 2016) revealed some interesting and often amusing explanations:

  • Jeanne Calment, whose death on August 4, 1997 at 122 makes her the longest-lived person on record. She smoked two cigarettes a day for almost a hundred years and enjoyed two pounds of chocolate a week, but she added extra virgin olive oil to almost everything she ate.
  • Susannah Mushatt Jones, who at 116 is currently the world’s oldest person, never smoked or drank, but indulges in four strips of bacon for breakfast every morning. Relatives theorize that having a very short marriage and no children help to explain her long life.
  • Jiroemon Kimura died at 116 in 2013 and was the world’s oldest man. He drank alcohol moderately and lived by the motto that one should only eat until 80 percent full.
  • More than one super ager credits daily alcohol consumption for keeping them alive so long. At 116, Emma Morano is the world’s second-oldest person, and drinks a glass of homemade brandy every day.