The science of healthy longevity.
Our job is to make the best available evidence understandable and useful — including being clear about where it is strong, and where it is not.
Six areas where the research is clearest.
Longevity
Strong evidenceIn a cohort of ~120,000 adults followed for decades, five low-risk lifestyle factors were associated with an estimated 14 additional years of life expectancy at age 50 for women and 12 for men.
Li et al., Circulation 2018 (observational).
Cognitive decline & dementia
Moderate evidenceThe Lancet Commission estimates that around 45% of dementia cases worldwide are associated with 14 potentially modifiable risk factors — a population-level estimate, not a personal guarantee.
Livingston et al., Lancet Commission 2020/2024.
Cardiovascular disease
Strong evidenceAcross 52 countries, nine modifiable factors accounted for roughly 90% of the population-attributable risk of a first heart attack.
Yusuf et al., Lancet 2004 (INTERHEART); Life's Essential 8, Circulation 2022.
Obesity & type 2 diabetes
Strong evidenceIn a randomised trial, an intensive lifestyle program reduced the incidence of type 2 diabetes by ~58% over three years, compared with ~31% for metformin. In DiRECT, structured weight management led to remission in 46% at one year and 36% at two years.
Knowler et al., NEJM 2002 (DPP); Lean et al., Lancet 2018 (DiRECT).
Stress, anxiety & depression
Moderate evidenceAn umbrella review of 97 meta-analyses (~128,000 participants) found physical activity to be effective in reducing symptoms of depression and anxiety. Trials differ in design and comparison, so it should be seen as a valuable complement to — not a replacement for — established treatment.
Singh et al., BJSM 2023; Jacka et al., BMC Medicine 2017 (SMILES).
Biomarkers
Moderate evidenceA compact panel — blood pressure, LDL/ApoB, HbA1c or fasting glucose, waist circumference/BMI, resting heart rate and cardiorespiratory fitness — captures much of the risk we can actually work with.
Mandsager et al., JAMA Netw Open 2018.
A simple, honest grading.
Strong evidence
Consistent findings across large human studies, including randomised trials where available.
Moderate evidence
Reasonably consistent human evidence, but with limitations in design, size or duration.
Promising / emerging
Early human data or strong mechanistic rationale — interesting, but not yet settled.
Insufficient evidence
Too little, too weak or too conflicting evidence to draw a useful conclusion today.
How we read the research.
Human evidence over mechanistic speculation
A plausible mechanism is a hypothesis. We look for what has been shown in people.
The totality of evidence over single studies
One striking study rarely changes the picture. The body of evidence does.
Health outcomes over surrogate markers
Moving a number is not the same as living better or longer.
Safety matters
Potential benefit is always weighed against potential harm and interactions.
Cost and burden matter
Something that is expensive, complicated or unpleasant rarely lasts.
Evidence changes — recommendations should too
We update when the evidence does, and we say so.
Science before hype
If something is uncertain, we would rather say so than sell it.
What we don't know yet.
Being useful also means being honest about the limits of current knowledge.
Most longevity supplements
Many popular compounds rest on animal or short-term human data. Long-term outcomes in people are largely unknown.
Biological age tests
Interesting research tools, but current consumer tests vary widely and are not established for guiding individual decisions.
Optimal protocols
Exact doses, timings and 'optimal' routines are usually less settled than the internet suggests. The basics are far better documented.
Individual response
Population averages do not predict any single person's response. That is a limitation we work with openly.
Genes matter less than many think.
Large population and pedigree studies have estimated the heritability of human longevity to be relatively low. Much of the rest is shaped by lifestyle, environment, social conditions and chance — some of which we can influence, and some of which we cannot.
Correlation is not causation. The figures above come from large observational studies and randomised trials as referenced; they describe groups, not individuals, and individual results vary.
Important
Longevity Institute provides health guidance based on lifestyle science. We are not a medical device, and we do not diagnose, treat or cure medical conditions. Always consult qualified health professionals about medical concerns. Our aim is to supplement — not replace — professional care.
Correlation is not causation. The figures cited come from large observational studies and randomised trials as referenced; individual results vary. Scores are a marker of progress — not a diagnosis.