Blue Zones: Why Sardines Matter More Than XXL Salmon Steaks

People who reach a very old age rarely follow rigid diet plans. Even so, the so-called Blue Zones – regions with unusually high numbers of very elderly people – show certain recurring patterns. One is that fish has a place in the diet, but in far smaller quantities than many health guides suggest. Above all, the focus is more likely to be on sardines than XXL salmon steaks.

What Blue Zones really do with fish

Blue Zones are areas where statistically far more people live to 90 or 100 than elsewhere. They include Okinawa in Japan, the Greek island of Ikaria, parts of Sardinia, Nicoya in Costa Rica and Loma Linda in California.

Researchers observing everyday life in these places find a clear pattern on the plate:

• Most calories come from plant-based foods.
• Animal products such as meat, cheese and eggs play only a minor part.
• Fish is eaten, but in surprisingly modest portions and not every day.

Simple meals based on vegetables, pulses, wholegrains and olive oil are typical. When fish is served, it is often twice a week, usually as a small piece shared at the table alongside plenty of accompaniments.

“In regions with especially high numbers of centenarians, fish appears on the menu regularly, but more as an accompaniment than the main attraction on the plate.”

Why small fish stand out

When people think of “healthy fish”, salmon is often the first thing that comes to mind. Eating patterns in the Blue Zones present a different picture: smaller oily sea fish are more likely to go into the pan, including sardines, sprats, herring and smaller cod species.

There are several reasons for this:

• More omega-3 fatty acids: These fish provide plenty of long-chain omega-3 fatty acids, which may protect the heart and blood vessels and reduce inflammation.
• Fewer contaminants: Small fish sit lower in the food chain. They accumulate less mercury and fewer other pollutants than large predatory fish such as swordfish or tuna.
• High nutrient density: As well as omega-3, they contain vitamin B12, iodine, selenium and high-quality protein – all nutrients that help the body remain capable for longer.

Eating a small tin of sardines, for example, provides a substantial amount of protein and omega-3 in just a few mouthfuls, without needing an XXL portion.

What longevity researchers recommend

Longevity researchers such as Valter Longo, who has studied diet and healthy ageing for years, describe a clearly plant-focused approach: vegetables, fruit, pulses, nuts and wholegrains form the foundation, with a small number of carefully chosen fish meals added.

“The rule of thumb from longevity research is: eat predominantly plant-based foods, supplemented by two to three small portions of fish a week – chosen carefully.”

From this perspective, the key points are:

• Do not plan fish as an everyday main meal.
• Choose oily, generally smaller species.
• Pay attention to quality and origin to keep contaminant exposure low.

How much fish per week makes sense

Health bodies such as the UK National Health Service (NHS) offer similar guidance to longevity research. They regard fish as beneficial for the heart and brain, while also cautioning against excessive quantities of heavily contaminated species.

Essentially, this means choosing small portions regularly rather than occasional fish feasts. Anyone viewing fish as one element of a largely plant-based diet comes fairly close to the patterns seen in Blue Zones.

Contaminant risk: how to limit exposure

Sea fish always involves a balance between nutrients and contaminants. Selecting the right varieties can reduce this tension.

• Choose small species: Sardines, herring, mackerel and smaller cod species absorb fewer heavy metals than large predatory fish.
• Build in variety: Alternating between different fish and seafood types spreads the risk.
• Sensitive groups should be more cautious: Pregnant and breastfeeding women, along with young children, should eat heavily contaminated fish only rarely.
• Keep an eye on origin: Certified fish that is sustainably caught or farmed is generally subject to better controls.

“The combination of a small quantity, a small species and plenty of variety makes it easier to gain the nutritional benefits while keeping contaminants under control.”

Practical tips: what a Blue Zone-friendly fish day looks like

Anyone wanting to bring this approach into daily life does not need to seek out exotic products. A typical day could look like this:

• Breakfast: Porridge oats with fruit, nuts and a little yoghurt – with no fish at all.
• Lunch: A large mixed salad with beans or chickpeas, olive oil and a small piece of grilled fish, approximately palm-sized.
• Evening meal: A vegetable stew with lentils and wholemeal bread, perhaps with two or three sardines on the side rather than as the main component.

This puts fish in the role of a supplement, while pulses, vegetables and wholegrains provide fullness and a sustained supply of fibre.

Sardines or salmon – which suits the longevity concept better?

The question “sardines or salmon?” comes up frequently. Both can have a place, but they offer different profiles:

• Sardines and similar fish: Small, oily, high in omega-3, often cheaper and comparatively low in contaminants.
• Salmon: Also rich in omega-3, but highly dependent on origin and farming conditions; wild varieties may contain more contaminants, while feed and rearing methods matter for farmed fish.

The patterns in Blue Zones clearly favour a “sardine principle”: small species, small amounts, but regularly. Salmon can be an addition, but it should not appear on the plate as a steak-sized portion every other day.

Why the rest of the plate matters almost more than fish

Fish never works in isolation. In regions with particularly large numbers of very elderly people, it is accompanied by other factors that may make the difference:

• Plenty of vegetables, pulses and wholegrains as everyday staples.
• Few highly processed convenience foods.
• A restrained approach to meat, processed meat and sweet foods.
• Regular movement built into daily life rather than fitness-gym marathons.
• Strong social ties and established shared-meal rituals.

Anyone who copies only the fish element while continuing to eat mainly fast food will not achieve the same effect as residents of a Greek island sharing the day’s catch with family and neighbours.

What can easily be put into practice every day

For everyday life in the UK, a few simple adjustments can help:

• Schedule one regular fish meal each week, then gradually increase to two or three.
• Make at least every second fish meal one based on small, oily species.
• With every fish portion, ensure that at least half the plate consists of vegetables.
• Make beans, lentils and chickpeas standard accompaniments rather than occasional additions.

People who adopt these habits come very close to the pattern researchers observe in villages with many residents over 90: fish as a deliberate, small source of nutrients within an overall simple, plant-focused diet – not a miracle cure, but one component of a long and hopefully healthy life.