Does eating fish help your heart and your brain?
Two portions of oily fish per week, as part of a varied and plant-rich diet, is a smart choice for most people when it comes to both heart and brain health. However, fish does not work as a standalone protective food.
Oily fish such as salmon, mackerel and tuna appear in many studies as part of a heart-healthy diet. The protective effect is largely due to omega-3 fatty acids. These suppress inflammatory processes, whereas fatty acids from sunflower and corn oil actually promote them1,2.
For the heart, the results are mixed. One analysis shows that 200 mg of omega-3 per day from fish can reduce the risk of sudden cardiac death by around 50%3. A large study with 118,469 participants followed for more than nine years found that people who ate the most fish had 14% fewer cardiovascular events, with fish being one of the most strongly contributing food groups4. However, another study with nearly 30,000 participants followed for nineteen years found NO significant association between eating fish on its own and the risk of heart disease or death5. Fish as a standalone food is therefore not proven to be protective.
The strongest heart-related evidence applies to the Mediterranean diet as a whole, of which fish is a component. Large randomised studies such as PREDIMED, Lyon Heart and CORDIOPREV show that this overall dietary pattern genuinely reduces cardiovascular disease and mortality6,7. Fish eaten as part of a varied, plant-rich diet therefore has the most evidence behind it, not fish as an isolated wonder food.
For the brain, omega-3 is particularly relevant. Brain tissue preferentially absorbs it and requires it for development and maintenance. Deficiencies are linked in multiple studies to cognitive decline in older adults and to sporadic Alzheimer's disease3,2. However, this evidence comes largely from observational studies and animal research. Large human studies demonstrating that eating fish genuinely prevents dementia do not yet exist.
Do pay attention to mercury: large predatory fish such as tuna, swordfish and shark can contain high amounts. For pregnant women this is a real risk, as mercury can harm the brain development of the unborn child2. For most other people, two portions of oily fish per week, preferably smaller species, is safe and likely beneficial.
The evidence consists of observational cohort studies, including one with 118,469 participants and one with approximately 30,000 participants, as well as mechanistic research into omega-3 fatty acids. For the Mediterranean diet as a whole, randomised studies exist (PREDIMED, Lyon Heart, CORDIOPREV), but these concern the overall dietary pattern rather than fish specifically. Large randomised studies linking fish consumption to cognition in humans are still lacking.
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.
How healthy are yoghurt and dairy for your heart and bones?
Yoghurt and dairy are a perfectly good choice for bone health for most people, and are likely neutral to mildly beneficial for the heart. Opt preferably for fermented products such as yoghurt, and keep an eye on your total saturated fat intake if you have an elevated cardiac risk.
Does eating spicy food help you live longer?
Eating spicy food regularly is linked to a lower chance of dying early, but whether it is the cause is not yet known. With stomach cancer, a little may be beneficial while a lot could actually be harmful, so moderation is key.
Does the Mediterranean diet help you live longer?
In large population studies, the Mediterranean diet is consistently linked to a lower chance of dying and less heart and blood vessel disease; those who want to follow the diet as a whole have the strongest evidence on their side.
Is eating organic food really healthier?
Eating organic probably does not give you better nutritional value, but it does lower your exposure to pesticide residues and to antibiotic-resistant bacteria via meat. For pregnant women and young children, that is the most concrete and well-supported argument.
Does the timing of your meals affect how long you live?
The timing of your meals is associated with biological ageing and risk of death, but cause and effect have not been proven. Eating early, a nightly fasting window of at least 13 hours and a regular eating pattern appear to be the best choices based on what is currently known.