What are the negative effects of smoked fish?

November 29, 2025 •

2 min read

According to the American Heart Association, a single 100-gram serving of smoked salmon can contain over 670 milligrams of sodium, highlighting a significant health concern. But what are the negative effects of smoked fish beyond its high salt content, and how does its processing impact your health?

Quick Summary

Smoked fish can pose several risks, such as exposure to carcinogenic compounds like PAHs and nitrosamines, high sodium levels that can affect cardiovascular health, and bacterial contamination, particularly listeria in cold-smoked products.

Key Points

Carcinogenic Compounds: The smoking process can create polycyclic aromatic hydrocarbons (PAHs) and nitrosamines, some of which are known carcinogens.
High Sodium Content: Smoked fish is high in sodium due to the brining and salting process, increasing the risk of high blood pressure and other cardiovascular issues.
Listeria Risk: Cold-smoked fish carries a risk of Listeria monocytogenes contamination, which is especially dangerous for pregnant women, older adults, and immunocompromised individuals.
Nutrient Loss: Heat-sensitive vitamins, such as Vitamin A, can be degraded during the smoking process, reducing some of the fish's nutritional value.
Vulnerable to Contaminants: Fish can accumulate environmental heavy metals and pollutants, which are not removed during the smoking process.
Moderation is Key: Due to these risks, smoked fish should be consumed in moderation, and high-risk groups should take extra precautions.

Carcinogenic Compounds Formed During Smoking

One of the significant health concerns with smoked fish is the presence of carcinogenic compounds. The smoking process creates substances like Polycyclic Aromatic Hydrocarbons (PAHs) and nitrosamines.

Polycyclic Aromatic Hydrocarbons (PAHs)

PAHs are formed during the incomplete burning of organic materials like wood. These compounds can transfer to the fish, especially with traditional smoking methods where fat drips onto the heat source. Benzo[a]pyrene (BaP), a Group 1 carcinogen, is a notable PAH linked to gastrointestinal cancers. Traditional smoking techniques can result in higher PAH levels compared to modern methods or liquid smoke.

Nitrosamines

Nitrosamines, such as N-nitrosodimethylamine (NDMA), can also be found in smoked foods. They form from the reaction of nitrites and amines in the fish. While less common in EU-regulated smoked fish with restricted nitrites, they can occur, especially if certain additives are used.

High Sodium Content and its Health Impact

Smoking often involves brining or salting, leading to high sodium levels in the final product compared to fresh fish. High sodium intake is linked to increased risk of high blood pressure, heart disease, stroke, and certain gastrointestinal issues.

Microbiological Contamination: The Threat of Listeria

Cold-smoked fish, processed at low temperatures without fully cooking, presents a risk of Listeria monocytogenes contamination. This bacterium can cause listeriosis, a serious infection, particularly for vulnerable groups like pregnant women, newborns, older adults, and those with weakened immune systems. To mitigate this risk, the Food Standards Agency advises at-risk individuals to thoroughly cook cold-smoked fish.

Potential for Environmental Contaminants

Fish can accumulate environmental pollutants like heavy metals (lead, mercury, cadmium) and persistent organic pollutants (PCBs, dioxins) from contaminated water. These contaminants are not removed by the smoking process.

Comparison of Hot vs. Cold Smoking


Feature	Hot-Smoked Fish	Cold-Smoked Fish
Temperature	At or above 80°C (176°F)	Below 30°C (86°F), often around 32-37°C (90-97°F)
Cooking State	Fully cooked, flaky texture	Partially cooked, soft and translucent texture
Listeria Risk	Very low, as high temperature kills bacteria	Higher risk, as low temperatures allow bacteria to survive and multiply
Carcinogen Risk	Can still contain PAHs, but often less than traditional cold smoking	Can have significant PAH content, especially with traditional methods
Texture & Taste	Cooked, smoky flavor	Raw-like texture, milder, cured flavor
Shelf-Life	Long if properly stored or canned	Shorter due to potential for bacterial growth

Nutritional Loss

The smoking process can cause some loss of heat-sensitive vitamins like Vitamin A, especially with longer smoking durations. While omega-3s are generally stable, some can be lost due to fat dripping.

Conclusion

While smoked fish offers nutritional benefits, potential negative effects of smoked fish include exposure to carcinogens (PAHs, nitrosamines), high sodium, and listeria risk, particularly from cold-smoked varieties. The smoking method (hot or cold) impacts safety. Choosing hot-smoked fish or thoroughly cooking cold-smoked fish is recommended for vulnerable groups. Moderate consumption and awareness of processing details can help minimize health hazards. Consult public health authorities like the CDC for official safety guidelines regarding listeria and other foodborne illnesses.

Frequently Asked Questions

Cold-smoked salmon is considered a higher-risk food due to the potential for listeria contamination, especially for vulnerable populations like pregnant women, older adults, and those with weakened immune systems. Hot-smoked salmon, which is cooked, is lower risk.

Hot smoking, which cooks the fish at a high temperature, is a critical step for eliminating most pathogenic bacteria, including listeria. However, recontamination can occur after the smoking process, so good hygiene practices are still crucial.

Vulnerable individuals can reduce their risk by thoroughly cooking cold-smoked fish until it is steaming hot. Additionally, purchasing from reputable sources and maintaining proper refrigeration helps minimize risk.

Most smoked fish products are high in sodium due to the salting process used for curing and preservation. The exact amount can vary by product and brand, but consumers with high blood pressure should be particularly mindful of their intake.

PAHs, or Polycyclic Aromatic Hydrocarbons, are carcinogenic compounds formed during the incomplete burning of organic materials, like the wood used for smoking. They can be deposited onto and absorbed by the fish, and some are known to be carcinogenic.

Yes, fish can accumulate environmental pollutants like heavy metals (mercury, cadmium) and other toxins (PCBs) from their habitat. The smoking process does not remove these contaminants.

Using liquid smoke generally results in lower levels of carcinogenic PAHs in the final product compared to traditional wood smoking, as it avoids the incomplete combustion of wood.