Shrimp salad: what we know comes from the shrimp

In an old randomized crossover trial in adults with normal blood lipids, eating 11 oz (300 g) of shrimp a day raised LDL cholesterol by 7.1 percent and HDL by 12.1 percent and cut triglycerides by 13 percent against a low-cholesterol baseline diet. Because HDL rose more than LDL, the cholesterol ratios did not get worse. That is a single trial whose abstract does not say how many people took part, and 300 g is more than the 182 g a whole cup of shrimp salad weighs in the US food survey. A 1990 feeding study in 18 men with normal lipids, with no randomization stated, found no change in blood lipids on a shrimp diet. We found no study of shrimp salad as a dish, so everything here is about the shrimp in it. The mayonnaise, the dressing and how long a ready-made salad has waited in the fridge sit outside every study we have.

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• According to the NIH Office of Dietary Supplements, shellfish are among the richest dietary sources of copper. — general population Evidence E source
  —

What a real portion looks like

• In the US food survey database, one cup of shrimp salad weighs 6.4 oz (182 g), and an unspecified serving is counted as 91 g. — US dietary survey portions Evidence E source
  1 cup = 182 g; quantity not specified = 91 g

What your body absorbs

• Adding 3.5 oz (100 g) of shrimp a day for six weeks raised selenium intake to about 127 mcg a day, and about 83% of the selenium from shrimp was absorbed. — 12 healthy young adults (9 women, 3 men), 6 weeks (n = 12) Evidence C source
  Apparent selenium absorption 83 +/- 4%; plasma selenium 95.2 to 101.5 microg/L

What cooking and storage change

• For shellfish boiled in the shell, the USDA retention table keeps about 60% of vitamin B12, 70% of potassium and phosphorus and 100% of zinc and calcium. — Finfish and Shellfish Products group, boiled with shell Evidence E source
  Retained: B12 60%, potassium 70%, phosphorus 70%, folate 75%, zinc 100%, calcium 100%

What it does to your health

• In a randomized crossover trial, 11 oz (300 g) of shrimp a day raised LDL cholesterol by 7.1% but HDL by 12.1% and cut triglycerides by 13%, so lipid ratios did not worsen. — normolipidemic adults, crossover diets vs low-cholesterol baseline Evidence B source
  LDL +7.1%, HDL +12.1%, triglycerides -13% vs baseline
• In a controlled feeding study, shrimp and squid diets did not change blood lipids in men with normal lipids, while oyster, clam, crab and mussel diets lowered some lipids. — 18 normolipidemic men fed six shellfish species (n = 18) Evidence C source
  No change in blood lipids on the shrimp diet

Safety, limits and interactions

• In US NHANES 2003-2020 data, shellfish intake was the strongest dietary predictor of higher blood PFAS, with a dose-response pattern. — US NHANES participants, 2003-2020 Evidence C source
  Dose-response association with higher total and individual serum PFAS

What people believe that the data does not support

• In a double-blind placebo-controlled challenge, all 15 people sensitized to shrimp tolerated 1,500 mg of shrimp-derived glucosamine without an immediate allergic reaction. — subjects sensitized to shrimp: positive skin test and ImmunoCAP class 2 or higher (n = 15) Evidence B source
  0 of 15 reacted to 1,500 mg shrimp-derived glucosamine

Who this works differently for

• Among 30 people with a history of reactions to shrimp, 9 (30%) reacted objectively when challenged with shrimp under blinded or open conditions. — individuals with history of immediate objective reactions after shrimp ingestion (n = 30) Evidence C source
  9/30 (30%) positive challenge
• Across 93 European studies, self-reported lifetime shellfish allergy was 0.4%, and challenge-verified shellfish allergy was about 0.1%. — all age groups, Europe, studies to 2021 (n = 93 studies) Evidence C source
  Self-reported 0.4% (95% CI 0.3-0.6); challenge-verified 0.1% (0.0-0.2)
• In pooled Chinese population studies, shrimp was among the most common food allergies, with a prevalence of 1.5%. — Chinese population-based studies Evidence C source
  Shrimp allergy prevalence 1.5%
• A scoping review of 46 studies found shellfish eating in pregnancy and early childhood linked to higher contaminant biomarkers, mostly mercury, and in several studies to lower birth weight. — pregnant and lactating women and children 0-2 years, 46 studies 2000-2022 (n = 46 studies) Evidence C source
  Higher contaminant biomarkers; mixed birth-weight findings; no link with preterm birth

What is still unknown

• In 27,801 US adults, fish eating was linked to slower biological aging, but shellfish eating showed no significant link. — 27,801 US adults, NHANES 1999-2020 (n = 27801) Evidence C source
  Shellfish: no significant association with PhenoAge

The bottom line

The one absorption study we have is about selenium. Twelve healthy young adults added 100 g of shrimp a day to their usual diet for six weeks. Their selenium intake rose from about 39 to 127 mcg a day, and about 83 percent of the selenium from the shrimp was absorbed, in a study with no control group. The NIH Office of Dietary Supplements lists shellfish among the richest food sources of copper, a statement about shellfish in general. For shellfish boiled in the shell, the USDA retention table keeps about 60 percent of vitamin B12, 70 percent of potassium and phosphorus and all of the zinc and calcium. That factor dates from 1975 and covers the whole fish and shellfish group, so read it as a rough guide. One belief was tested directly. In a double-blind placebo-controlled challenge, all 15 people with a positive skin test to shrimp took 1,500 mg of shrimp-derived glucosamine without an immediate allergic reaction. The sample is small, and the result applies to glucosamine tablets from particular makers. It says nothing about eating shrimp. Shrimp allergy is rarer than self-reports suggest, at least in Europe. Across 93 European studies, 0.4 percent of people said they had ever had a shellfish allergy (95% CI 0.3 to 0.6), and about 0.1 percent had it confirmed by a food challenge (0.0 to 0.2), with most studies at moderate risk of bias. Pooled Chinese population studies put shrimp allergy at 1.5 percent, among the most common food allergies there. In a 1988 study of 30 people with a history of immediate reactions to shrimp, 9 reacted objectively when challenged, in a design without randomized order. Who should be careful. If you have a confirmed shrimp allergy, this salad is shrimp, and the glucosamine result above does not cover it. In US NHANES data from 2003 to 2020, shellfish eating was the strongest dietary predictor of higher blood PFAS, with levels climbing as intake rose. That study is cross-sectional and its abstract gives no size for the effect. For pregnancy and the first two years of life, a scoping review of 46 observational studies linked shellfish eating to higher contaminant markers in the body, mostly mercury. Several of those studies reported lower birth weight, the results overall were mixed, and none found a link with preterm birth. We have no card on how safely a ready-made salad keeps or on the allergens in its dressing, so this page cannot speak to them. Whether shellfish does anything for long-term health is still open. In 27,801 US adults, shellfish eating showed no significant link with a blood-based measure of biological aging, a cross-sectional result that cannot say much about cause.

Sources

1. ssd-daily-r8-11 · agency fact sheet
   The richest dietary copper sources include shellfish, seeds and nuts, organ meats, wheat-bran cereals, whole-grain products, and chocolate [1,2].
   NIH Office of Dietary Supplements, Copper Fact Sheet for Health Professionals · checked 2026-10-01
2. ssd-daily-r8-12 · food composition dataset
   Shrimp salad; 1 cup: 182 g; Quantity not specified: 91 g
   USDA FoodData Central survey (FNDDS) 2024-10-31, food code 27450070, fdc_id 2706837 · checked 2026-10-01
3. ssd-daily-r8-03 · balance study
   Twelve healthy young subjects (9F and 3M) received 100 g of shrimps each day for six weeks in addition to their habitual diet. ... The selenium intake increased from 39.4 +/- 15.3 microg/d to 127 +/- 5.5 microg/d with the addition of shrimps. The apparent absorption of selenium from shrimps was 83 +/- 4%.
   J Trace Elem Med Biol, 2001 · checked 2026-10-01
4. ssd-daily-r8-13 · nutrient retention table
   SHELLFISH,W/SHELL,BOILED: vitamin_b12_ug 60%; phosphorus_mg 70%; potassium_mg 70%; folate_total_ug 75%; calcium_mg 100%; zinc_mg 100%
   USDA Table of Nutrient Retention Factors, Release 6 (2007), code 2701 · checked 2026-10-01
5. ssd-daily-r8-01 · randomized crossover trial
   In a randomized crossover trial, a diet containing 300 g shrimp/d, which supplied 590 mg dietary cholesterol/d, significantly increased low-density-lipoprotein (LDL) cholesterol by 7.1% (P = 0.014) and high-density-lipoprotein (HDL) cholesterol by 12.1% (P = 0.0001) when compared with a baseline diet matched for fat content but containing only 107 mg cholesterol/d. However, because the percentage increase in LDL cholesterol was less than for HDL cholesterol, the shrimp diet did not worsen the ratio of total cholesterol to HDL cholesterol or the ratio of LDL to HDL cholesterol. Moreover, shrimp consumption decreased triacylglycerol (triglyceride) concentrations by 13% (P = 0.004).
   Am J Clin Nutr, 1996 · checked 2026-10-01
6. ssd-daily-r8-04 · controlled feeding study
   Squid and shrimp diets, higher in cholesterol and lower in n-3 fatty acids, did not change the blood lipids.
   Am J Clin Nutr, 1990 · checked 2026-10-01
7. ssd-daily-r8-09 · cross-sectional
   Shellfish consumption was the strongest dietary predictor of higher total and individual PFAS concentrations, with dose-response relationships, while meat intake was modestly associated and fish intake showed weak or inconsistent associations.
   Chemosphere, 2026 · checked 2026-10-01
8. ssd-daily-r8-02 · randomized controlled trial
   Fifteen subjects with positive skin tests to shrimp and an ImmunoCAP class level of two or greater were selected for a double-blind placebo-controlled food challenge (DBPCFC) using glucosamine-chondroitin tablets containing 1,500 mg of synthetically produced (control) or shrimp-derived glucosamine. ... All subjects tolerated 1,500 mg of both shrimp-derived or synthetic glucosamine without incident of an immediate hypersensitivity response.
   Clin Exp Allergy, 2006 · checked 2026-10-01
9. ssd-daily-r8-05 · food challenge study
   Thirty individuals with history of immediate, objective, adverse reactions after shrimp ingestion underwent double-blind, placebo-controlled shrimp-food challenges. ... Positive challenge responses occurred in 9/30 subjects (30%); six of these subjects experienced a positive response during the double-blind phase.
   J Allergy Clin Immunol, 1988 · checked 2026-10-01
10. ssd-daily-r8-06 · meta-analysis of prevalence studies
    The overall pooled estimates for all age groups of self-reported lifetime prevalence were as follows: cow's milk (5.7%, 95% confidence interval 4.4-6.9), egg (2.4%, 1.8-3.0), wheat (1.6%, 0.9-2.3), soy (0.5%, 0.3-0.7), peanut (1.5%, 1.0-2.1), tree nuts (0.9%, 0.6-1.2), fish (1.4%, 0.8-2.0) and shellfish (0.4%, 0.3-0.6). The point prevalence of food challenge-verified allergy were as follows: cow's milk (0.3%, 0.1-0.5), egg (0.8%, 0.5-1.2), wheat (0.1%, 0.01-0.2), soy (0.3%, 0.1-0.4), peanut (0.1%, 0.0-0.2), tree nuts (0.04%, 0.02-0.1), fish (0.02%, 0.0-0.1) and shellfish (0.1%, 0.0-0.2).
    Allergy, 2023 · checked 2026-10-01
11. ssd-daily-r8-07 · meta-analysis of prevalence studies
    The common allergic foods were determined to be mango, shrimp, egg, milk, and crab, with the prevalence of 1.9%, 1.5%, 1.4%, 1.3%, 1.3%, respectively
    Allergy Asthma Proc, 2023 · checked 2026-10-01
12. ssd-daily-r8-08 · scoping review
    Overall, shellfish consumption was associated with higher biomarkers of environmental contaminants, with mercury being the most studied and having the strongest evidence base. ... Preterm birth was not associated with shellfish consumption, but newborn anthropometry showed mixed results, with several studies reporting lower birth weight with higher shellfish consumption.
    Nutr Res Rev, 2025 · checked 2026-10-01
13. ssd-daily-r8-10 · cross-sectional
    However, shellfish consumption showed no significant link to BA.
    Ir J Med Sci, 2026 · checked 2026-10-01