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Research · Diets

Pescatarian diet

No trial has tested a pescatarian diet against heart attacks, cancer or death. In cohorts, fish eaters had 13% less heart disease than meat eaters, and lower death and colorectal cancer rates than nonvegetarians. One small trial found weight loss matched an omnivorous diet. One UK cohort linked it to more hip fractures, and an earlier analysis did not.

Add to Bio HackChecked 2026-11-13
Status
A dietary pattern, not a regulated product.
Also called
pescetarian, pesco-vegetarian, pescovegetarian, fish eater, pesce-vegetarian, seagan
Followed for
heart health, weight loss, diabetes prevention, cancer prevention, longevity

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help3

Reported risks1

What people follow it for, and what was found

Shown to help3

Limited

Heart disease

Linked to 13% lower ischemic heart disease in fish eaters than meat eaters in one UK cohort followed 18 years.

Compared with meat eaters in the same UK cohort (EPIC-Oxford), people who ate meat whether or not they ate fish, dairy or eggs [1]

The numbers and sources
Effect
Fish eaters had lower rates of ischemic heart disease than meat eaters after adjusting for sociodemographic and lifestyle factors (HR 0.87, 95% CI 0.77 to 0.99) [1].
Population
48,188 UK adults without heart disease, including 7,506 fish eaters, followed 18.1 years [1]. Observational.
Sources
[1]
Caveats
Observational, one cohort [1].
Limited

Death from any cause

Linked to 19% lower death rates in pesco-vegetarians than nonvegetarians over about 6 years in one Adventist cohort.

Compared with nonvegetarians in the same Seventh-day Adventist cohort in North America [2]

The numbers and sources
Effect
The adjusted hazard ratio for death from any cause in pesco-vegetarians was 0.81 (95% CI 0.69 to 0.94) against nonvegetarians [2].
Population
73,308 Seventh-day Adventists in North America followed a mean 5.79 years [2]. Observational.
Sources
[2]
Caveats
Observational, one cohort with short follow-up. Associations were larger in men than in women [2].
Limited

Colorectal and other cancers

Linked to 43% lower colorectal cancer in one Adventist cohort and 10% lower total cancer in UK Biobank, against people who ate meat.

Compared with nonvegetarians in the same Seventh-day Adventist cohort in North America [3]; regular meat-eaters in UK Biobank [4]

The numbers and sources
Effect
In the Adventist cohort, pesco-vegetarians had lower colorectal cancer rates than nonvegetarians (HR 0.57, 95% CI 0.40 to 0.82) [3]. In UK Biobank, fish eaters had lower total cancer (HR 0.90, 95% CI 0.84 to 0.96) than regular meat eaters, and male fish eaters had lower prostate cancer (HR 0.80, 95% CI 0.65 to 0.99) [4].
Population
77,659 Seventh-day Adventists followed 7.3 years [3]; 472,377 UK adults including 10,696 fish eaters followed 11.4 years [4]. Observational.
Sources
[3], [4]
Caveats
Observational. The UK Biobank authors write that residual confounding or differences in cancer detection may explain some differences [4].

Mixed results1

Limited

Type 2 diabetes

Mixed results: pesco-vegetarians had lower diabetes prevalence in one analysis of an Adventist cohort, and new diabetes was not significantly lower in another.

Compared with nonvegetarians in the same Seventh-day Adventist cohort in North America [5]; non-vegetarians in the same Adventist cohort in the US and Canada [6]

The numbers and sources
Effect
Diabetes prevalence was 4.8% in pesco-vegetarians against 7.6% in nonvegetarians (adjusted OR 0.70, 95% CI 0.61 to 0.80) [5]. Over two years, new diabetes developed in 1.29% of pesco-vegetarians and 2.12% of nonvegetarians, and the pesco-vegetarian group was not among the groups with significantly lower risk [6].
Population
60,903 Adventists in North America [5]; 41,387 Adventists free of diabetes at baseline [6]. Observational.
Sources
[5], [6]
Caveats
Observational, self-reported diabetes, one cohort [5][6].

Not shown to help1

Limited

Weight

One small trial found weight loss on a pesco-vegetarian diet matched an omnivorous diet over 6 months. A large cohort linked it to slightly lower BMI.

Compared with nonvegetarians in the same Adventist cohort in North America [5]; an omnivorous diet, and vegan, vegetarian and semi-vegetarian diets, all low-fat and low-glycemic-index, in South Carolina adults [7]

The numbers and sources
Effect
In a 6-month trial, weight fell 3.2% on a pesco-vegetarian diet and 3.1% on an omnivorous diet, both low-fat and low-glycemic-index, against 7.5% on a vegan diet [7]. In the Adventist cohort, mean BMI was 26.3 in pesco-vegetarians and 28.8 in nonvegetarians [5].
Population
63 adults with overweight or obesity, 13 assigned to the pesco-vegetarian diet [7]; Adventist adults, observational [5].
Sources
[5], [7]
Caveats
Very small trial arms, and the omnivorous group had fewer meetings [7].

How trials defined it

EPIC-Oxford defined fish eaters as people who ate fish but no meat [1]. The Adventist cohort classified diet type from a food frequency questionnaire [2], and UK Biobank from dietary questions at recruitment [4]. The weight trial used low-fat, low-glycemic-index diets in every arm for 6 months, without an emphasis on calorie restriction [7].

Risks

Mixed results1

Limited

Hip fracture

Mixed results: one UK analysis linked fish eating without meat to 26% more hip fractures, and an earlier analysis of the same cohort found no fracture difference.

The numbers and sources
Effect
In EPIC-Oxford over 17.6 years, fish eaters had more hip fractures than meat eaters (HR 1.26, 95% CI 1.02 to 1.54), about 2.9 more per 1,000 people over 10 years [8]. An earlier analysis over 5.2 years found no difference in total fractures for fish eaters (rate ratio 1.01, 95% CI 0.88 to 1.17) [9].
Population
54,898 UK adults including 8,037 fish eaters [8]; 34,696 UK adults including 4,901 fish eaters [9]. Observational.
Sources
[8], [9]
Caveats
Observational. The earlier analysis used self-reported fractures and looked at total fractures, not hip fractures alone [9].

Sources

  1. Tong TYN, Appleby PN, Bradbury KE, et al. Risks of ischaemic heart disease and stroke in meat eaters, fish eaters, and vegetarians over 18 years of follow-up: results from the prospective EPIC-Oxford study. BMJ. 2019. https://doi.org/10.1136/bmj.l4897
  2. Orlich MJ, Singh PN, Sabaté J, et al. Vegetarian dietary patterns and mortality in Adventist Health Study 2. JAMA Internal Medicine. 2013. https://doi.org/10.1001/jamainternmed.2013.6473
  3. Orlich MJ, Singh PN, Sabaté J, et al. Vegetarian dietary patterns and the risk of colorectal cancers. JAMA Internal Medicine. 2015. https://doi.org/10.1001/jamainternmed.2015.59
  4. Watling CZ, Schmidt JA, Dunneram Y, et al. Risk of cancer in regular and low meat-eaters, fish-eaters, and vegetarians: a prospective analysis of UK Biobank participants. BMC Medicine. 2022. https://doi.org/10.1186/s12916-022-02256-w
  5. Tonstad S, Butler T, Yan R, et al. Type of vegetarian diet, body weight, and prevalence of type 2 diabetes. Diabetes Care. 2009. https://doi.org/10.2337/dc08-1886
  6. Tonstad S, Stewart K, Oda K, et al. Vegetarian diets and incidence of diabetes in the Adventist Health Study-2. Nutrition, Metabolism and Cardiovascular Diseases. 2013. https://doi.org/10.1016/j.numecd.2011.07.004
  7. Turner-McGrievy GM, Davidson CR, Wingard EE, et al. Comparative effectiveness of plant-based diets for weight loss: a randomized controlled trial of five different diets. Nutrition. 2015. https://doi.org/10.1016/j.nut.2014.09.002
  8. Tong TYN, Appleby PN, Armstrong MEG, et al. Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study. BMC Medicine. 2020. https://doi.org/10.1186/s12916-020-01815-3
  9. Appleby P, Roddam A, Allen N, et al. Comparative fracture risk in vegetarians and nonvegetarians in EPIC-Oxford. European Journal of Clinical Nutrition. 2007. https://doi.org/10.1038/sj.ejcn.1602659

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