Is it safe to eat dairy with fish? (3 risks)

By Dr Anny Manrich (PhD) | Reviewed by Dr Anny Manrich (PhD)

Page last updated: 24/10/2023 | Next review date: 24/10/2025

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The contents of this article are fact-based except otherwise stated within the article.

Author bio

Dr Anny Manrich PhD is a food Engineer with expertise in Food Technology, Natural Polymers, Edible Films, Enzymes, and Nanotechnology. She writes and reviews content on these topics.

Dr Anny Manrich’s Highlights:

Research and Technology at the Brazilian Agricultural Research Corporation
PhD in Chemical Engineering with a focus on Biochemistry at the Federal University of Sao Carlos/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany
Bachelor of Food Engineering at the University of Campinas/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany

“To solve a problem, global vision and multifactorial understanding are necessary. Therefore, in addition to expertise, one should seek multidisciplinary thinking connected with science and reality” – Dr Anny Manrich, PhD.

Professional Experience:

Dr Anny Manrich’s Experience Joining the Brazilian Agricultural Research Corporation, as soon as she completed her doctorate,

Dr Anny Manrich has worked on several projects, including the more than three-year partnership project with BRF, a major food producer in Brazil. As a postdoctoral fellow.

Dr Anny Manrich has also contributed to several business consultancies and research projects of the National Nanotechnology Laboratory System in areas such as food technology, fibres, films and coatings and Nanotechnology; in a very determined way, having a great team relationship, being creative and committed.

Growing concerns about the safe introduction of nanomaterials into today’s life emphasises the need to create regulatory documentation in front of characterising, using and testing them. Dr Anny Manrich worked for two years on a characterization project for nanoscale materials, with the aim of exploring their possible health effects.

Despite not having specific academic training in packaging or polymeric films, Dr Anny Manrich works at the Brazilian Agricultural Research Corporation in areas of edible and biodegradable films produced from agricultural waste and in the development of films with greater resistance to water, having articles published in renowned scientific journals, which demonstrates her multidisciplinary understanding and creativity.

In addition, she worked for four years as a consultant to a food company to develop a line of snacks that are healthy and that add functional ingredients, physiologically active compounds that bring health benefits, made from fruits and vegetables, enabling diet improvement, disease prevention and reduction of nutritional deficiencies.

Dr Anny Manrich participated as a member of the examination board for two Master’s exams and one PhD exam at the Department of Chemical Engineering of the Federal University of São Carlos.

Education:

2001 Bachelor in Food Engineering at the State University of Campinas, Brazil
1999 One year scholarship at the Technical University of Munich
2004 Master in Chemical Engineering at the Federal University of São Carlos, Brazil
2012 PhD in Chemical Engineering at the Federal University of São Carlos, Brazil
2010 One year scholarship at the Technical University of Munich

The main publications of Dr. Anny Manrich are:

Articles

Manrich, A., Moreira, F. K., Otoni, C. G., Lorevice, M. V., Martins, M. A., & Mattoso, L. H. (2017). Hydrophobic edible films made up of tomato cutin and pectin. Carbohydrate Polymers, 164, 83-91.

Mendes, J. F., Norcino, L. B., Martins, H. H. A., Manrich, A., Otoni, C. G., Carvalho, E. E. N., … & Mattoso, L. H. C. (2020). Correlating emulsion characteristics with the properties of active starch films loaded with lemongrass essential oil. Food Hydrocolloids, 100, 105428.

Norcino, L. B., Mendes, J. F., Natarelli, C. V. L., Manrich, A., Oliveira, J. E., & Mattoso, L. H. C. (2020). Pectin films loaded with copaiba oil nanoemulsions for potential use as bio-based active packaging. Food Hydrocolloids, 106, 105862.

Manrich, Anny, et al. Immobilization of trypsin on chitosan gels: Use of different activation protocols and comparison with other supports. International Journal of Biological Macromolecules 43.1 (2008): 54-61.

Manrich, Anny; Komesu, Andrea ; Adriano, Wellington Sabino; Tardioli, Paulo Waldir ; Giordano, Raquel Lima Camargo . Immobilization and Stabilization of Xylanase by Multipoint Covalent Attachment on Agarose and on Chitosan Supports. Applied Biochemistry and Biotechnology, v. 161, p. 455-467, 2010.

Mendes, J. F., Martins, J. T., Manrich, A., Neto, A. S., Pinheiro, A. C. M., Mattoso, L. H. C., & Martins, M. A. (2019). Development and physical-chemical properties of pectin film reinforced with spent coffee grounds by continuous casting. Carbohydrate polymers, 210, 92-99..

Milessi, T. S., Kopp, W., Rojas, M. J., Manrich, A., Baptista-Neto, A., Tardioli, P. W., … & Giordano, R. L. (2016). Immobilization and stabilization of an endoxylanase from Bacillus subtilis (XynA) for xylooligosaccharides (XOs) production. Catalysis Today, 259, 130-139.

Mendes, J. F., Norcino, L. B., Manrich, A., Pinheiro, A. C. M., Oliveira, J. E., & Mattoso, L. H. C. (2020). Development, physical‐chemical properties, and photodegradation of pectin film reinforced with malt bagasse fibers by continuous casting. Journal of Applied Polymer Science, 137(39), 49178.

Mendes, J. F., Martins, J. T., Manrich, A., Luchesi, B. R., Dantas, A. P. S., Vanderlei, R. M., … & Martins, M. A. (2021). Thermo-physical and mechanical characteristics of composites based on high-density polyethylene (HDPE) e spent coffee grounds (SCG). Journal of Polymers and the Environment, 29, 2888-2900..

Mendes, J. F., Norcino, L. B., Martins, H. H., Manrich, A., Otoni, C. G., Carvalho, E. E. N., … & Mattoso, L. H. C. (2021). Development of quaternary nanocomposites made up of cassava starch, cocoa butter, lemongrass essential oil nanoemulsion, and brewery spent grain fibers. Journal of Food Science, 86(5), 1979-1996.

Manrich, A., Martins, M. A., & Mattoso, L. H. C. (2021). Manufacture and performance of peanut skin cellulose nanocrystals. Scientia Agricola, 79.

Nascimento, V. M., Manrich, A., Tardioli, P. W., de Campos Giordano, R., de Moraes Rocha, G. J., & Giordano, R. D. L. C. (2016). Alkaline pretreatment for practicable production of ethanol and xylooligosaccharides. Bioethanol, 2(1)..

Manrich, Anny, de Oliveira, J. E., Martins, M. A., & Mattoso, L. H. C. Physicochemical and Thermal Characterization of the Spirulina platensis. J. Agric. Sci. Technol. B, v. 10, p. 298-307, 2020.

Book Chapter

Terra, I. A. A., Aoki, P. H., Delezuk, J. A. D. M., Martins, M. A., Manrich, A., Silva, M. J., … & Miranda, P. B. (2022). Técnicas de Caracterização de Polímeros. Nanotecnologia Aplicada a Polímeros, 614.

Conference Papers

Ferreira, L. F., Luvizaro, L. B., Manrich, A., Martins, M. A., Júnior, M. G., & Dias, M. V. (2017). Comparação da estabilidade de suspensões poliméricas de amido/tocoferol e quitosana/tocoferol. In: CONGRESSO BRASILEIRO DE POLÍMEROS, 14., 2017, Águas de Lindóia, SP.

Manrich, A., Hubinger, S. Z., & Paris, E. C. (2017). Citotoxicidade causada por nanomateriais: avaliação do micronúcleo. In: WORKSHOP DA REDE DE NANOTECNOLOGIA APLICADA AO AGRONEGÓCIO, 9., 2017, São Carlos. Anais… São Carlos: Embrapa Instrumentação, 2017. p. 655-658.

Manrich, Anny, et al. Immobilization and Stabilization of Xylanase by multipoint covalent attachment on Glyoxyl Agarose Support. The 31st Symposium on Biotechnology for Fuels and Chemicals. 2009.

Manrich, Anny, et al. Application of immobilized xylanase on hydrolysis of soluble wood hemicelluloses after using microwave and organosolv pre-treatments. The 32nd Symposium on Biotechnology for Fuels and Chemicals. 2010.

You can view some of Dr Anny’s work below and links to her professional profile.

Research Gate: https://www.researchgate.net/profile/Anny-Manrich-2

Scopus: https://www.scopus.com/authid/detail.uri?authorId=23103497100

Google Scholar: https://scholar.google.com/citations?hl=en&user=Ea9qpr0AAAAJ

Linkedin: https://br.linkedin.com/in/anny-manrich-20693129

Dr Anny Manrich (PhD)

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Reviewer bio

Dr Anny Manrich PhD is a food Engineer with expertise in Food Technology, Natural Polymers, Edible Films, Enzymes, and Nanotechnology. She writes and reviews content on these topics.

Dr Anny Manrich’s Highlights:

Research and Technology at the Brazilian Agricultural Research Corporation
PhD in Chemical Engineering with a focus on Biochemistry at the Federal University of Sao Carlos/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany
Bachelor of Food Engineering at the University of Campinas/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany

Professional Experience:

Dr Anny Manrich’s Experience Joining the Brazilian Agricultural Research Corporation, as soon as she completed her doctorate,

Dr Anny Manrich has worked on several projects, including the more than three-year partnership project with BRF, a major food producer in Brazil. As a postdoctoral fellow.

Dr Anny Manrich participated as a member of the examination board for two Master’s exams and one PhD exam at the Department of Chemical Engineering of the Federal University of São Carlos.

Education:

2001 Bachelor in Food Engineering at the State University of Campinas, Brazil
1999 One year scholarship at the Technical University of Munich
2004 Master in Chemical Engineering at the Federal University of São Carlos, Brazil
2012 PhD in Chemical Engineering at the Federal University of São Carlos, Brazil
2010 One year scholarship at the Technical University of Munich

The main publications of Dr. Anny Manrich are:

Articles

Manrich, A., Martins, M. A., & Mattoso, L. H. C. (2021). Manufacture and performance of peanut skin cellulose nanocrystals. Scientia Agricola, 79.

Manrich, Anny, de Oliveira, J. E., Martins, M. A., & Mattoso, L. H. C. Physicochemical and Thermal Characterization of the Spirulina platensis. J. Agric. Sci. Technol. B, v. 10, p. 298-307, 2020.

Book Chapter

Conference Papers

You can view some of Dr Anny’s work below and links to her professional profile.

Research Gate: https://www.researchgate.net/profile/Anny-Manrich-2

Scopus: https://www.scopus.com/authid/detail.uri?authorId=23103497100

Google Scholar: https://scholar.google.com/citations?hl=en&user=Ea9qpr0AAAAJ

Linkedin: https://br.linkedin.com/in/anny-manrich-20693129

Dr Anny Manrich (PhD)

View More north_east

In this article, we will discuss whether it is safe to eat dairy with fish, the risks and benefits of eating dairy and fish, the drawbacks of eating dairy with fish and how can you eat dairy with fish safely.

Is it safe to eat dairy with fish?

Yes, it is safe to eat dairy with fish, unless one of the ingredients is spoiled or in the case of food allergies to fish or dairy (5, 6, 7).

Fish and dairy are both sources of proteins and minerals and eating fish and dairy has many benefits and drawbacks, as well as risks (5, 6). Fish and dairy can be eaten together, although their separate consumption may be a better option, due to nutritional factors (3, 4).

Is the risk of eating dairy with fish a myth?

No, the risk of eating dairy with fish is not a myth. The concerns regarding eating dairy with fish can be found in some Jewish eating traditions, which require that milk sources should not be cooked together with any food in the category of meat (8).

However, the explanation to this concern can be explained by biological facts, as the mixture of different sources of proteins may prolong the digestive process and impair the absorption of nutrients.

What are the possible risks of eating fish and dairy?

The possible risks of eating fish and dairy are present in the following cases: microbial spoilage of fish or dairy, allergy to fish or milk products and lactose intolerance. The possible risks are summarised in the table below:

Microbial spoilage of fish or dairy

Products and dairy products are perishable and host of many pathogenic microorganisms. The consumption of contaminated fish or contaminated dairy can cause foodborne illnesses (5, 7).

Allergy to fish or milk protein

Allergy to fish protein is less common than allergy to milk protein, however, both are possible and lead to allergic reactions, such as skin rashes, asthma and anaphylaxis (5, 6).

Lactose intolerance

Ingesting dairy may be a risk to individuals who are lactose intolerant, depending on the amount of lactase present in the dairy.

Aged cheeses are lactose-free and many other processed products, such as yoghurt, are lactose-free or contain a very low amount of lactose in their composition (6).

What are the benefits of eating fish and dairy?

The benefits of eating fish and dairy are the many nutrients provided by these food sources. Fish and dairy products both contain a considerable amount of proteins of high quality and good assimilation by the human body (3, 4, 6).

Proteins are sources of amino acids, which constitute the muscles, bones, body tissues and enzymes and their consumption is essential to maintain a good functioning of the body (3).

Insufficient ingestion of proteins can lead to many diseases, weakness, bone loss, anaemia and cardiac failure.

Fish proteins as well as dairy proteins have a high biological value, good protein digestibility and a high quantity of indispensable amino acids. In addition, fish and milk contain minerals and vitamins, such as calcium, and vitamin B12 (3, 4, 5, 6).

Can you eat fish and dairy in the same meal?

Yes, you can eat fish and dairy in the same meal, however, there are some drawbacks (8). Examples of fish with dairy meals are “fish with cheese sauce”, “cream of salmon soup” and “smoked fish baked in milk” (9).

The drawback of eating milk and fish in the same meal is the possible lower protein absorption and the lower absorption of the minerals iron and calcium, when compared to the ingestion of these two protein sources separately (1, 2).

Effective protein digestion depends on many factors, including the types and quantity of enzymes that are released into the gastric system.

Once proteins are ingested, the proteolytic enzymes are released. They attach to the proteins, and begin the hydrolysis process, cleaving proteins into amino acids.

When different sources of protein are consumed together in the same meal, a greater number of enzymes are required to properly digest these proteins.

However, the amount of enzymes is limited, which may result in an impaired digestive process. As a consequence, the digestibility and assimilation of the proteins can be blemished.

How to consume fish and dairy safely?

To safely consume fish and dairy, consider consuming fish in one meal, such as lunch or dinner, and dairy in another meal, such as breakfast or in between meals.

Consuming fish or other meat with dairy products or milk can result in an incomplete digestive process and lowered protein absorption when compared to the ingestion of these protein sources separately (1, 2, 8).

In addition, it is important to choose fresh ingredients with a good appearance and free from signs of microbial spoilage. Spoiled fish is identified by its unpleasant ammonia-like “fishy” or rancid odour, loss of texture and gas production (5).

Spoilage of milk and other dairy products can be identified by the production of gas, the presence of off-odours such as rancid, fermented or “fruity” and, in the case of cheeses, the growth of coloured mould formations (7).

Conclusion

In this article, we discussed the possible risks of eating fish and dairy, the possible drawbacks of eating fish and dairy in the same meal and the benefits of fish and dairy.

Fish and dairy are important sources of proteins, minerals and vitamins for the human diet, however, many risks are associated with their consumption, when eaten separately or together.

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References

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Gan J, Bornhorst GM, Henrick BM, German JB. Protein digestion of baby foods: study approaches and implications for infant health. Molecular nutrition & food research. 2018 Jan;62(1):1700231.

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Logsdon CD, Ji B. The role of protein synthesis and digestive enzymes in acinar cell injury. Nature reviews Gastroenterology & hepatology. 2013 Jun;10(6):362-70.

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Wu G. Dietary protein intake and human health. Food & function. 2016;7(3):1251-65.

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Comerford K, Pasin G. Emerging Evidence for the Importance of Dietary Protein Source on Glucoregulatory Markers and Type 2 Diabetes: Different Effects of Dairy, Meat, Fish, Egg, and Plant Protein Foods. Nutrients [Internet] 2016;8(8):446. Available from: http://dx.doi.org/10.3390/nu8080446

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Adedeji OB, Okerentugba PO, Innocent-Adiele HC, Okonko IO, Ojeniyi SO, Adejoro SA, Mohamed SA. Benefits, public health hazards and risks associated with fish consumption. New York Science Journal. 2012;5(9):33-61.

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Thorning TK, Raben A, Tholstrup T, Soedamah-Muthu SS, Givens I, Astrup A. Milk and dairy products: good or bad for human health? An assessment of the totality of scientific evidence. Food & nutrition research. 2016 Jan 1;60(1):32527.

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Pal M, Mulu S, Tekle M, Pintoo SV, Prajapati J. Bacterial contamination of dairy products. Beverage and food world. 2016;43(9):40-3.

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Mazokopakis EE. The Prohibition of Meat and Milk Mixing in the Same Meal: A Brief Theological and Medical Approach to a Jewish Dietary Law. European Journal of Theology and Philosophy. 2023 Jan 14;3(1):19-21.

9.-

Recipes [Internet]. Victoria.ac.nz. [cited 2023 Oct 24]. Available from: https://nzetc.victoria.ac.nz/tm/scholarly/tei-Gov13_04Rail-t1-body-d24-d5.html

Food Safety