Are Sardines Good for Your Skin? A Doctor's Guide to Marine Nutrition

By Dr Ivona Igerc, GDC-registered doctor and aesthetic practitioner, founder of Dr Ivy London. Published: August 2026.

I grew up in the Mediterranean, where my grandmother served sardines with olive oil and garlic-sautéed blitva, and insisted they were the reason for strong bones and good skin. Decades into aesthetic practice, I find the nutritional logic behind that plate holds up well. What does not hold up is the way marine nutrition is currently sold online, where a genuinely good food gets loaded with claims it cannot carry.

This article separates the two.

What is actually in a tin of sardines

Per 100g of canned sardines, drained, eaten with the softened bones:

Two things stand out. The calcium figure only applies if you eat the bones, which canning softens enough to be edible. And the mercury figure is roughly a hundredth of what accumulates in large predator fish, because sardines are small, short-lived and low on the food chain. The NHS lists sardines among the oily fish it actively recommends. (Sources: NHS, Fish and shellfish; US FDA and EPA seafood mercury data.)

The nutrients, and what may honestly be said about each

UK advertising rules allow only specific, authorised wordings when a food or nutrient is linked to health. Those wordings exist because they are the versions the evidence actually supports. They are worth quoting exactly, because the gap between the authorised claim and the usual online version tells you where the science stops.

Omega-3: EPA and DHA

The authorised claim is that EPA and DHA contribute to the normal function of the heart, at a daily intake of 250mg. A single tin comfortably exceeds that.

The mechanism people cite for skin is real biochemistry: long-chain omega-3 fatty acids are incorporated into cell membranes and shift the balance of the inflammatory signalling molecules the body produces from them. That is why omega-3 is studied in inflammatory conditions at all. What does not follow is a promise about your face. There is no authorised UK health claim connecting omega-3 to skin, and the clinical studies in skin are small, short and often combine omega-3 with other ingredients.

So the accurate statement is this. Omega-3 is a nutrient your skin barrier is partly built from, adequate intake is sensible, and anyone selling you a specific skin outcome from a fish is going beyond the evidence.

The skin barrier

Fatty acids from the diet are incorporated into cell membranes, including those in the skin. A well-supported barrier holds water better, which is measured in research as reduced transepidermal water loss. Note the direction: you want that number to go down, not up.

This is a good reason to eat oily fish. It is not a reason to skip a moisturiser. Topical lipids, ceramides and humectants act on the barrier directly and quickly; diet acts slowly and diffusely, and it is the floor rather than the ceiling.

Selenium

Selenium contributes to the protection of cells from oxidative stress. That is the authorised wording, and it is well substantiated. A 100g tin provides most of an adult's daily reference intake. Selenium is a genuine strength of this food.

Vitamin D, calcium and phosphorus

Vitamin D contributes to the normal absorption and utilisation of calcium and phosphorus, and calcium is needed for the maintenance of normal bones. Canned sardines deliver all three together, which is unusual in a single food.

A note on UK vitamin D specifically: between October and early March, sunlight in the UK is too weak for the skin to make enough vitamin D, and NHS advice is that everyone consider a daily 10µg supplement through the autumn and winter. Food alone rarely covers it here. (Source: NHS, Vitamin D.)

Zinc and protein

Zinc contributes to the maintenance of normal skin and to normal DNA synthesis. Protein contributes to the maintenance of normal bones. Sardines supply both.

The astaxanthin question, answered properly

Astaxanthin appears in almost every article about marine nutrition and skin, usually with the figures 6,000 times vitamin C, 800 times CoQ10 and 550 times vitamin E.

Two corrections are needed, and I would rather make them than repeat the received version.

Sardines are not a meaningful source of astaxanthin. Astaxanthin is the carotenoid that turns flesh and shell pink-red. It is found in salmon, trout, krill, shrimp, crab and lobster. Sardines have pale, silvery flesh, which is the visual clue. If astaxanthin is what you are after, the sources are sockeye salmon, trout and krill.

The multiples come from one specific laboratory test. They originate in a 2007 paper by Nishida and colleagues measuring how effectively different antioxidants quench a single reactive species, singlet oxygen, in a test tube. Astaxanthin performs exceptionally well on that one measure. That is not the same as being thousands of times more powerful than vitamin C in a human being, where absorption, distribution and the type of oxidative stress involved all matter. The figure is accurate about the assay and misleading about the person.

Astaxanthin remains an interesting compound. It simply is not the reason to eat sardines.

Facial bone structure: the part that is genuinely underrated

The facial skeleton changes shape with age. This is well documented in imaging and osteological research, and it is one of the more useful things for patients to understand.

Across adult life the orbital aperture enlarges, the maxilla loses height and projection, and the mandibular angle opens. Published estimates put orbital enlargement at roughly 15 to 20 per cent by the seventh decade, maxillary height loss at around 8 to 15 per cent, and mandibular angle change at 3 to 7 degrees. The soft tissue of the face sits on that framework. When the framework changes, the soft tissue above it changes position, which is why some of what reads as sagging is a structural change rather than a skin change.

That is the accurate half. Here is the honest limit: I am not aware of evidence that any particular food preserves facial bone specifically. What is established is that calcium, vitamin D, phosphorus, vitamin K and protein are needed for the maintenance of normal bone generally, and that canned sardines with bones are an unusually complete source of them. Whole-body bone nutrition is worth taking seriously on its own terms. Extending that to a promise about your jawline would be an overreach, and you should be sceptical of anyone who makes it.

Who gets the most from oily fish

Any adult in the UK benefits from meeting the oily fish recommendation, and most of us do not. A few groups have particular reason to pay attention.

People with dry or easily disrupted skin. Dietary fatty acids contribute to the lipids the barrier is built from, so adequate intake supports the foundation that topical barrier care then works on.

People managing inflammatory skin conditions. Eczema, rosacea, psoriasis and acne are medical conditions, and food is not a treatment for any of them. What is true is that omega-3 is studied in inflammatory conditions and that a diet meeting the oily fish recommendation is a reasonable thing to do alongside proper medical care. If you have one of these conditions, your GP or dermatologist leads; diet supports.

Women through and after menopause. Falling oestrogen is associated with reduced skin lipid content and hydration, alongside an accelerated loss of bone density. Both of those are nutrition-relevant, and both are worth discussing with a clinician rather than solving with a tin.

Anyone recovering from a procedure. I discuss nutrition with patients before and after treatment. Zinc, selenium, protein and omega-3 are all involved in the body's normal repair processes, and arriving well nourished is a sensible thing to do. I would put this no more strongly than that: sound nutrition supports the body doing what it normally does, it does not push it beyond that.

How much, and who should limit it

This is the part most articles on this subject leave out, and it is the part with an actual number attached.

UK guidance is at least two portions of fish a week, one of which should be oily. A portion is around 140g.

There is an upper limit for some people. Oily fish carry higher levels of environmental pollutants than other seafood, so the NHS advises no more than two portions of oily fish a week for girls, women planning a pregnancy or who may have a child one day, and women who are pregnant or breastfeeding. Everyone else has no specified maximum for oily fish. (Source: NHS, Fish and shellfish.)

If you are pregnant, breastfeeding, taking anticoagulant medication, or managing a diagnosed condition, take dietary advice from your own clinician rather than from a skincare article, including this one.

The Mediterranean plate, and what makes it work

My grandmother never served sardines alone. They came with cold-pressed extra virgin olive oil and garlic-sautéed blitva, which is Swiss chard. Two of the three elements of that plate have a clear nutritional rationale.

Olive oil supplies fat alongside the meal, which matters because vitamins A, D, E and K are fat-soluble and are absorbed better in the presence of dietary fat.

Swiss chard is one of the richest dietary sources of vitamin K, and vitamin K contributes to the maintenance of normal bones. Paired with the calcium from the sardine bones, that combination has a genuine logic to it.

One correction to the version of this that circulates: chard is not a notable source of glutathione, and dietary glutathione is in any case largely broken down during digestion rather than absorbed intact. The reason to eat the greens is the vitamin K and the wider nutrient density, which is reason enough.

Where topical skincare fits, and where it does not

Marine-derived ingredients appear on both sides of aesthetics, and it is worth being clear that they are not interchangeable.

Polynucleotides (PDRN) are DNA fragments derived from salmon or trout, used as injectable treatments in clinic. Published studies report improvements in skin quality measures, but they are generally small, short, and often combine polynucleotides with other agents, so the evidence base is early rather than settled. This is a clinic treatment and a consultation subject, not something to buy online.

Dr Ivy London's range is topical and plant-derived. The exosomes in the Regenerative Exosome Serum come from Centella Asiatica, not from fish, and the serum is a cosmetic used at home. It is not a source of nutrition, it does not do what a diet does, and it is not a substitute for the medical care an inflammatory skin condition needs.

The honest order of operations is unglamorous. Eat well and get the oily fish in. Protect your skin from UV daily. Use a barrier-supporting topical routine consistently. Then, if you want a supportive layer on top of that foundation, look at the exosome range. A serum sitting on top of a poor foundation is doing the least interesting job available to it.

If a clinic treatment is what you are considering, book a consultation rather than self-prescribing from an article.

Frequently asked questions

Are sardines good for your skin?
They are a good source of the nutrients skin is built from, including long-chain omega-3, zinc, selenium and protein. UK rules permit specific authorised claims for those nutrients, such as zinc contributing to the maintenance of normal skin, but there is no authorised claim linking omega-3 to skin. Sardines are a sound nutritional foundation rather than a skin treatment.

How many sardines should I eat a week?
UK guidance is at least two portions of fish a week, one of them oily, with a portion being around 140g. Girls, women who may have a child one day, and women who are pregnant or breastfeeding should have no more than two portions of oily fish a week because of pollutant levels. Other adults have no specified maximum for oily fish.

Do sardines contain astaxanthin?
Not in meaningful amounts. Astaxanthin is the pink-red carotenoid found in salmon, trout, krill, shrimp, crab and lobster. Sardines have pale flesh and are not a notable source. The widely quoted figures about astaxanthin being thousands of times stronger than vitamin C come from a single laboratory measure of one reactive species and do not translate directly to effects in the body.

Are canned sardines as good as fresh?
For calcium, canned are better, because the canning process softens the bones enough to eat and the bones are where the calcium is. Omega-3, selenium and vitamin D are well retained in canning. Choose sardines canned in olive oil or water, and check the salt content if you are watching your intake.

Is there mercury in sardines?
Very little. Sardines are small, short-lived and low on the food chain, so they accumulate far less mercury than large predator fish such as shark, swordfish and marlin. Published median mercury levels for sardines are around 0.013 parts per million, among the lowest of any seafood.

Can diet replace skincare, or skincare replace diet?
Neither. Diet supplies the raw materials the body builds skin from and acts slowly across the whole body. Topical skincare acts locally and quickly on the surface, and daily SPF prevents damage that no diet can offset. They work on different problems, so they are not alternatives to each other.

The bottom line

My grandmother was right about sardines, though not for the reasons the internet now gives. They are an inexpensive, low-mercury, nutrient-dense food that supplies omega-3, calcium, vitamin D, selenium, zinc and protein in one tin, and most people in the UK do not eat enough oily fish.

What they are not is a cosmetic treatment. The strongest version of this argument does not need the exaggeration: eat the fish, use the SPF, keep the routine simple and consistent, and let each thing do the job it is actually good at.