The near future of human longevity will be determined by progress in medical technology. This is the only thing that might result in the option to live in good health for decades or more beyond the span of years enjoyed by your grandparents: there's no other way to extend healthy life to this degree. It's new medicine or nothing, and the critical factor is whether proposed forms of rejuvenation biotechnology such as those described in the SENS proposals are developed rapidly or slowly. At present the pace is slow, but we may yet manage to obtain the funding and attention needed to turn rejuvenation into a field as large and energetic as cancer research or stem cell medicine.
Present day good health practices cannot greatly extend your life, and they cannot even reliably ensure that you reach extreme old age in good shape, or indeed at all. Most exceptionally healthy people don't make it to 90 - but of course the toll is far worse among those who are sedentary, fat, and smoke. The consensus from various studies appears to be that you can give yourself the expectancy of five to ten additional years above the average through regular exercise, and you can drop five to ten years or more below the average through being obese or smoking. Calorie restriction may or may not be as good as exercise for human life expectancy, though it is expected by the research community to extend life. The benefits to short term measures of health are arguably far better than those produced by exercise, but it's hard to find a big enough study population for calorie restriction to produce the same sorts of quality statistic data as are available for exercise.
Taking the 80/20 approach to being healthy isn't just a quality of life and lower medical expense thing nowadays, however. It was in the past, because there was no possibility of radical life extension through medical technology on the horizon. Now, however, rejuvenation biotechnology is within a few decades of implementation, with that countdown starting just as soon as the funding ramps up to appreciable levels. How long will it take to generate the funds and interest? No one knows.
So who will make it to survive into the era of rejuvenation and the defeat of degenerative aging? Certainly most of the people born within the past decade. But those of us presently in the middle of life are looking at a great deal less certainty. For hundreds of millions of people a decade one way or another will be the difference between death and living to be young again, for as long as you care to keep going. Are you one of the people in that zone of uncertainty? Perhaps - but you'll never know until it's too late. That's why the whole healthy lifestyle thing is important: it's one of the only two ways in which you can shift the odds in a favorable direction, with the other being to help accelerate research and development.
With this in mind, here are a few recent research results on the topic of health and lifestyle. They are a reminder that a better lifestyle is a good thing from the point of view of your likely length of life, medical expenditures, and the risk of suffering age-related medical conditions.
Vegetarian diets are associated with reduced death rates in a study of more than 70,000 Seventh-day Adventists with more favorable results for men than women. There were 2,570 deaths among the study participants during a mean (average) follow-up time of almost six years. The overall mortality rate was six deaths per 1,000 person years. The adjusted hazard ratio (HR) for all-cause mortality in all vegetarians combined vs. nonvegetarians was 0.88, or 12 percent lower, according to the study results. The study notes that vegetarian groups tended to be older, more highly educated and more likely to be married, to drink less alcohol, to smoke less, to exercise more and to be thinner.
A large, multi-center study led by Johns Hopkins researchers has found a significant link between lifestyle factors and heart health, adding even more evidence in support of regular exercise, eating a Mediterranean-style diet, keeping a normal weight and, most importantly, not smoking. The researchers found that adopting those four lifestyle behaviors protected against coronary heart disease as well as the early buildup of calcium deposits in heart arteries, and reduced the chance of death from all causes by 80 percent over an eight-year period.
To examine the impact of these lifestyle choices on memory throughout adult life, UCLA researchers and the Gallup organization collaborated on a nationwide poll of more than 18,500 individuals between the ages of 18 and 99. Respondents were surveyed about both their memory and their health behaviors, including whether they smoked, how much they exercised and how healthy their diet was.
"We found that the more healthy lifestyle behaviors were practiced, the less likely one was to complain about memory issues." In particular, the study found that respondents across all age groups who engaged in just one healthy behavior were 21 percent less likely to report memory problems than those who didn't engage in any healthy behaviors. Those with two positive behaviors were 45 percent less likely to report problems, those with three were 75 percent less likely, and those with more than three were 111 percent less likely.