Which diet is best supported by evidence for a long, healthy life?
For anyone looking to use diet to invest in a long and healthy life, the Mediterranean diet is currently the best-supported choice. Large human studies consistently show positive effects on both cardiovascular health and cognitive health.
Of all the dietary patterns studied, the Mediterranean diet has the strongest evidence base for a long and healthy life. Multiple large prospective studies and intervention trials show a consistent association with lower rates of cardiovascular disease, reduced mortality and longer lifespan1,2. It is also linked to a lower risk of type 2 diabetes, less overweight and lower blood pressure. The evidence is largely observational, so other lifestyle factors play a role. But the consistency across so many large studies is impressive.
For the brain, there are also positive signals. Multiple studies in humans suggest that the Mediterranean diet is associated with less cognitive decline in older age and a lower risk of Alzheimer's disease3,4. This evidence is less extensive than that for cardiovascular disease, but it is certainly there.
The so-called Blue Zones, such as Sardinia and the Greek island of Ikaria, show that long-lived populations traditionally eat a largely plant-based diet in moderate amounts. But researchers caution: the fact that a dietary pattern is found in a long-lived population does not prove that it is the cause of that longevity. The eating patterns in these zones are also not uniform and change over time.
Intermittent fasting, also known as time-restricted eating, shows promising effects on weight and disease prevention in mouse studies and smaller human studies, and also appears to have a positive influence on gut health5,6. However, large, long-term studies in humans are still lacking. Caloric restriction, eating less without malnutrition, is identified in molecular and animal research as one of the most powerful strategies for slowing biological ageing processes. Direct evidence in healthy humans over the long term is not yet available.
Popular high-protein diets deserve a note of caution. Animal protein has been linked in multiple observational studies to a higher risk of kidney damage and protein loss through urine7. Plant-based protein appears to place a lower burden on the kidneys. The evidence is not yet fully conclusive, but the concerns are real enough to take seriously, especially if you already have an elevated risk of kidney disease.
Based on 8 claims from published studies (PMIDs: 34204683, 34423871, 35780634, 38955141, 38790068, 32669325, 39059383). The Mediterranean diet is best supported by prospective studies and intervention trials. Fasting and caloric restriction are partly based on animal research and early human studies. Blue Zone evidence is observational and not causal. All associations are correlational unless stated otherwise.
Is a low-carbohydrate or ketogenic diet good for longevity?
A ketogenic diet can help with weight problems and metabolic disorders, but for people who simply want to live longer and healthier, no proven advantages over a varied diet have been demonstrated. Those who exercise intensively may even be at a disadvantage.
Do you live longer by following the Mediterranean diet?
In large population studies, the Mediterranean diet is consistently associated with lower mortality and less cardiovascular disease; those who want to follow the diet as a whole have the strongest evidence on their side.
Are beans and legumes good for longevity?
Large observational studies consistently show that people who eat more legumes have a lower risk of death. For most people, a daily serving of legumes is well supported by the evidence; older adults should also pay attention to getting sufficient protein overall.
Do you live longer on a vegetarian or plant-based diet?
A high-quality plant-based diet is associated with less premature death. However, eating strictly vegetarian or vegan has not been proven to be better than a varied diet that occasionally includes meat or fish.
Does eating less help you live longer?
In laboratory animals the effect on lifespan is well established, but in healthy humans direct evidence is lacking. A moderate and sustainable eating pattern is wiser than extreme restriction; discuss major changes to your diet with a dietitian or doctor.
Do you actually live longer if you structurally eat fewer calories?
In laboratory animals, eating less convincingly extends lifespan, but this has not yet been demonstrated for healthy people without excess weight. If you want to benefit from what has been shown, eating moderately less or following an interrupted eating pattern are the safest, most reasonably supported options.