It is undeniably the case that both diet and exercise influence the course of aging, though the size of the beneficial effect, even in the case of optimal lifestyle choices, is nowhere near as large as we'd all like it to be. Animal studies show calorie restriction extending maximum life span in mice by up to 40%, as well as lesser effects from various other forms of dietary strategy. Exercise meanwhile doesn't extend life span in mice, but does postpone age-related dysfunction and disease. Unfortunately, the effects on life span due to any of the strategies that are based on the metabolic effects of exercise and reduced calorie intake scale down as species life span scales up. These lifestyle choices upregulate stress response mechanisms, such as the cellular housekeeping systems of autophagy, resulting in more functional, less damaged cells. Yet calorie restriction, while extending mouse life span significantly, adds no more than a few years at most to human life spans.
That said, the beneficial effects of a good diet and regular moderate exercise are highly reliable, and they cost nothing beyond the time and willpower needed to introduce them into one's lifestyle. Modest, reliable, and free effects can be worth the effort. Just recognize that, at the end of the day, much more will be needed to avoid the same fate as every other human who has ever lived, aged, and died. We need the development of new biotechnologies capable of addressing the root causes of aging in order to live longer and in better health than can be provided via a good lifestyle. Only technology can purchase us additional decades of healthy life, or extend the human life span by more than a few years beyond its present limits.
The largest study to date of cardiorespiratory fitness in healthy people found that moving more is linked to living longer, regardless of age, sex, and starting fitness level. "People think they have to start going to the gym and exercising hard to get fitter. But it doesn't have to be that complicated. For most people, just being more active in daily life - taking the stairs, exiting the metro a station early, cycling to work - is enough to benefit health since levels are so low to start with. The more you do, the better."
The study included 316,137 adults aged 18-74 years who had their first occupational health screening between 1995 and 2015 in Sweden. Cardiorespiratory fitness was measured using a submaximal cycle test and expressed as maximal oxygen uptake (VO2 max) in ml/minute/kg body weight. This is the maximum amount of oxygen the heart and lungs can provide the muscles during exercise. You can estimate your VO2 max using either submaximal cycle tests, treadmill tests, or walking tests. Swedish national registries were used to obtain data on all-cause mortality and first-time cardiovascular events (fatal and non-fatal myocardial infarction, angina pectoris, or ischaemic stroke) during 1995-2015. The risk of all-cause mortality and cardiovascular events fell by 2.8% and 3.2%, respectively, with each millilitre increase in VO2 max.
Power depends on the ability to generate force and velocity, and to coordinate movement. In other words, it is the measure of the work performed per unit time (force times distance); more power is produced when the same amount of work is completed in a shorter period or when more work is performed during the same period. Climbing stairs requires power - the faster you climb, the more power you need. Muscle power gradually decreases after 40 years of age. "We now show that power is strongly related to all-cause mortality. But the good news is that you only need to be above the median for your sex to have the best survival, with no further benefit in becoming even more powerful."
The study enrolled 3,878 non-athletes aged 41-85 years who underwent a maximal muscle power test using the upright row exercise between 2001 and 2016. The average age of participants was 59 years, 5% were over 80, and 68% were men. During a median 6.5-year follow-up, 247 men (10%) and 75 women (6%) died. Median power values were 2.5 watts/kg for men and 1.4 watts/kg for women. Participants with a maximal muscle power above the median for their sex (i.e. in quartiles three and four) had the best survival. Those in quartiles two and one had, respectively, a 4-5 and 10-13 times higher risk of dying as compared to those above the median in maximal muscle power.
Researchers examined data from a total of 12,658 men from the Health Professionals Follow-Up Study, tracking them from 2008 to 2012. The team used criteria from the Alternate Healthy Eating Index-2010 to assess the quality of each of the men's diets and assign an individual score. These criteria included six food categories for which higher intake is better (vegetables, fruit, whole grains, nuts and legumes, long-chain omega-3 fatty acids and polyunsaturated fatty acids); one food category for which moderate intake is better (alcohol), and four categories for which lower intake is better (sugar-sweetened beverages and fruit juice, red and processed meats, trans fatty acids and sodium).
Researchers found that higher diet scores (meaning better diet quality) were strongly associated with decreased odds of physical impairment, including a 25 percent lower likelihood of developing impairment in physical function with aging. An overall healthy diet pattern was more strongly associated with better physical function than an individual component or food. But the team did see that greater intake of vegetables, nuts, and lower intake of red or processed meats and sugar-sweetened beverages each modestly lowered risk of impairment.