Queso fresco: calcium, and a Listeria record in pregnancy

In a randomized stable-isotope study in 12 young women, the body absorbed 37.7% of the calcium from a calcium-rich European fresh cheese and 42.2% from a traditional one, with no significant difference between the two. Queso fresco itself was not tested. Eight US samples of queso fresco held about 602 mg of calcium per 3.5 oz (100 g), ranging from 552 to 713. The same samples held about 627 mg of sodium per 3.5 oz (100 g), so a 21 g slice brings about 132 mg. The reason this cheese has a reputation is Listeria. In a 2000 North Carolina outbreak traced to raw-milk cheese sold door to door, 11 of 13 patients were pregnant and 5 pregnancies ended in stillbirth. Eating queso fresco carried 7.3 times the odds of infection, with a very wide interval (95% CI 1.4 to 37.5) because the outbreak was small. The cheese in that outbreak was made from unpasteurised milk, but pasteurized is not the safe answer. FDA advises pregnant women, adults over 65 and people with weakened immunity to avoid all queso fresco-type cheeses, pasteurized included, because the cheese can pick up Listeria again in an unsanitary plant. CDC gives the same group one way to eat it: heated in the dish to 165°F (74°C), or until steaming hot. In a 2021 US outbreak linked to queso fresco, 12 of the 13 people who fell ill were hospitalized, 2 pregnancies were lost and 1 person died.

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

How much is actually in it

• Across 8 US samples, queso fresco held about 627 mg sodium per 3.5 oz (100 g) (range 462 to 759) and 602 mg calcium (range 552 to 713). — USDA Foundation Foods, Cheese, queso fresco, solid, 8 analyzed samples (n = 8 samples) Evidence E source
  Per 100 g: sodium 626.5 mg (462-759), calcium 601.8 mg (552-713), total fat 23.36 g (20.46-26.81), saturated fat 13.95 g (11.15-15.64), protein 18.9 g, water 51.4 g, vitamin D 0

What a real portion looks like

• The US food survey counts a slice of queso fresco as 21 g and an ounce as 28 g, carrying about 132 mg and 178 mg of sodium. — USDA FNDDS 2021-2023 household measures, Queso Fresco, code 14133000 (n = 1 FNDDS record) Evidence E source
  Cracker-size slice 9 g, cubic inch 18 g, slice 21 g, 1 oz 28 g, 1 cup 135 g. Sodium 626 mg/100 g, 131.5 mg per slice, 177.5 mg per oz

What your body absorbs

• In a randomized stable-isotope study in 12 young women, 37.7% of the calcium from a new calcium-rich fresh cheese and 42.2% from a traditional fresh cheese was absorbed, with no significant difference between the two. — 12 healthy women aged 20-29 years, six test foods in two Latin squares, 2-day treatments with 2-week washouts (n = 12) Evidence B source
  Fractional calcium absorption 37.7% (SD 10.2) from new Ca-rich fresh cheese vs 42.2% (SD 11.6) from traditional fresh cheese, not significantly different
• In stable-isotope studies in 32 young women, iron added to fresh cheese was absorbed at 20.5% to 28.7% when the cheese was eaten alone, but only 6.9% to 8.4% when eaten with bread and butter. — 32 young women, two crossover stable isotope studies, fresh cheese fortified with 2.5 mg iron (n = 32) Evidence B source
  Fractional iron absorption 20.5% (iron-enriched yeast) vs 28.7% (ferrous sulfate), p = 0.0007, cheese alone. With bread and butter 6.9% vs 8.4%

What cooking and storage change

• FDA advises cooking queso fresco-type cheese in the dish to at least 165°F (74°C), keeping it at or below 40°F (4°C) and not keeping opened leftovers. — consumers of queso fresco-type cheeses Evidence E source
  Cook the cheese in the dish to at least 165°F (74°C); keep at or below 40°F (4°C); do not keep opened leftovers
• A global meta-analysis of 173 studies found Listeria monocytogenes in 3.44% of raw milk samples against 0.60% of pasteurized milk samples. — 173 prevalence studies of milk and dairy supply chains worldwide (n = 173 studies) Evidence C source
  Raw milk 3.44% (95% CI 2.61% to 4.28%) vs pasteurized milk 0.60% (0.00% to 2.06%). Dairy products 4.60%, supply chain environment 8.69%

Safety, limits and interactions

• In a 2021 US outbreak linked to queso fresco, 13 people fell ill, 12 were hospitalized, 2 pregnancies were lost and 1 person died. FDA counts 12 more outbreaks from 1998 to 2014 tied to soft cheese from pasteurized milk, 8 of them queso fresco-type. — 2021 US multistate outbreak linked to queso fresco; US soft-cheese outbreaks 1998 to 2017 (n = 13) Evidence E source
  2021: 13 ill, 12 hospitalized, 2 pregnancy losses, 1 death; 12 further outbreaks 1998 to 2014 from pasteurized-milk soft cheese, 8 of them queso fresco-type
• In Spain in 2012, two listeriosis cases were traced to a Latin-style fresh cheese made from pasteurized milk, and batches of it tested positive for Listeria. — two listeriosis cases in Bizkaia, Spain, August 2012 (n = 2) Evidence D source
  Latin-style fresh cheese made from pasteurized milk confirmed contaminated with Listeria monocytogenes; product withdrawn
• In a 2010 Arizona case-control study, eating queso fresco was linked with about 7 times the odds of sporadic Campylobacter infection. — statewide case-control study of sporadic Campylobacter infection in Arizona, 2010 Evidence C source
  Queso fresco OR 7.11 in the final multivariate model
• A 2004-2005 survey in Sonora, Mexico found Listeria monocytogenes in 3.4% of queso fresco samples bought at retail markets. — 349 samples from farms, cheese processing plants and retail markets in Sonora, Mexico, over 12 months (n = 349 samples) Evidence C source
  3.4% prevalence of L. monocytogenes in retail queso fresco. All 4 positives in part one were retail queso fresco

What people believe that the data does not support

• The American Academy of Pediatrics states that the claimed benefits of raw milk products have not been shown and that pasteurized milk gives equivalent benefits without the added infection risk. — policy statement on raw milk and milk products for pregnant women, infants and children Evidence E source
  Position: benefits of raw milk not demonstrated, pasteurized milk equivalent without added bacterial infection risk

Who this works differently for

• FDA advises people vulnerable to listeriosis, pregnant women among them, to avoid all queso fresco-type cheeses. Most sold in shops are pasteurized, but FDA notes they can pick up Listeria again in an unsanitary plant. — people vulnerable to listeriosis: pregnant women, unborn and newborn babies, adults over 65, people with weakened immune systems Evidence E source
  Avoid all queso fresco-type cheeses, pasteurized included; pasteurized cheese can be recontaminated in an unsanitary plant
• CDC tells people at higher risk, including pregnant women, to avoid any unheated queso fresco-type cheese whether made with pasteurized or raw milk, and lists it as safer only when heated to 165°F or until steaming hot. — people at higher risk for Listeria: pregnant, 65 or older, weakened immune system Evidence E source
  Avoid any unheated queso fresco-type cheese made with pasteurized or raw milk; choose it only heated to 165°F or until steaming hot
• Of 17 US listeriosis outbreaks from soft cheese in 1998 to 2014, 11 involved Latin-style cheese and caused 54% of cases. The share of outbreaks from soft cheese made with pasteurized milk rose from 5% before 2007 to 33% after. — listeriosis outbreaks linked to soft cheese, United States, 1998 to 2014 (n = 17 outbreaks) Evidence C source
  Latin-style cheese in 11 of 17 soft-cheese outbreaks (65%) and 98 cases (54%); outbreaks from pasteurized-milk soft cheese rose from 5% (1998 to 2006) to 33% (2007 to 2014), p = 0.009
• In a 2008-2009 US outbreak among pregnant Hispanic women, all 7 cases had eaten Mexican-style cheese, with 5.89 times the odds of controls. The outbreak strain was found in asadero cheese made from pasteurized milk. — pregnant Hispanic women with outbreak-strain listeriosis, October 2008 to March 2009, five US states (n = 7 cases, 43 controls) Evidence C source
  All 7 cases against 60% of controls ate Mexican-style cheese, OR 5.89 (95% CI 1.07 to infinity); outbreak strain found in asadero cheese made from pasteurized milk
• In a 2000 North Carolina listeriosis outbreak traced to cheese made from raw milk, 11 of 13 patients were pregnant, with 5 stillbirths, and eating queso fresco carried 7.3 times the odds of infection. — 13 Hispanic case patients (12 women aged 18-38, 11 pregnant) and matched controls, Winston-Salem, October 2000 to January 2001 (n = 13 cases) Evidence C source
  Queso fresco matched OR 7.3 (95% CI 1.4 to 37.5). Door-to-door unlabeled cheese matched OR 17.5 (2.0 to 152.5). 5 stillbirths, 3 premature deliveries, 3 infected newborns
• An umbrella review of nine systematic reviews found listeriosis in pregnancy occurred mostly in the third trimester (66%) and rarely in the first (3%). — 9 systematic reviews covering 330 studies and 487 patients, listeriosis in pregnancy and up to 4 weeks postnatally (n = 9 systematic reviews) Evidence C source
  66% of infections in the third trimester vs 3% in the first
• Pooled outbreak data put the median incubation of pregnancy-associated listeriosis at 27.5 days, ranging 17 to 67 days, much longer than other forms. — 37 invasive listeriosis cases with a single confirmed food exposure (12 pregnancy-associated) and 9 gastroenteritis outbreaks (n = 37 cases) Evidence C source
  Pregnancy-associated median 27.5 days (17 to 67) vs CNS 9 days (1 to 14) and bacteremia 2 days (1 to 12)
• The US FDA advises that pregnant women are about 10 times more likely to get listeriosis than other healthy adults. — pregnant women in the US Evidence E source
  About 10 times higher likelihood of listeriosis than other healthy adults (agency statement)

The bottom line

Pregnancy is where this matters most. The US FDA states that pregnant women are about 10 times more likely to get listeriosis than other healthy adults, a figure its page gives without citing the analysis behind it. In pooled outbreak data on 12 pregnancy-associated cases, illness appeared a median of 27.5 days after the contaminated food, ranging from 17 to 67 days, so a meal weeks ago can be the source. An umbrella review of nine systematic reviews found that 66% of reported listeriosis in pregnancy occurred in the third trimester and 3% in the first. Those reviews rest mostly on case reports, so the figures describe where cases were found and do not give a risk for each trimester. Pasteurization lowers the odds without making them zero. A global meta-analysis of 173 studies found Listeria in 3.44% of raw milk samples against 0.60% of pasteurized milk samples. That counts contaminated milk and does not count illness, and cheese can still pick up bacteria at the plant after the milk is pasteurized. Of 17 US listeriosis outbreaks from soft cheese between 1998 and 2014, 11 involved Latin-style cheese and caused 54% of cases. The share traced to soft cheese made with pasteurized milk rose from 5% before 2007 to 33% after. In a 2008 to 2009 outbreak among pregnant Hispanic women, all 7 cases had eaten Mexican-style cheese, and the outbreak strain was found in asadero cheese made from pasteurized milk. In Spain in 2012, two cases were traced to a Latin-style fresh cheese made from pasteurized milk. FDA advises keeping queso fresco at or below 40°F (4°C) and not keeping opened leftovers. In Sonora, Mexico, in 2004 and 2005, 3.4% of queso fresco samples bought at retail markets carried Listeria, and the survey abstract does not say whether they were pasteurized. In a 2010 Arizona case-control study, eating queso fresco was linked with 7.11 times the odds of sporadic Campylobacter infection. The abstract gives no confidence interval and does not say whether the cheese was made from raw milk. The American Academy of Pediatrics states that the claimed benefits of raw milk products have not been shown in evidence-based studies and that pasteurized milk gives equivalent benefits without the added risk of infection. The rest of the meal changes what you absorb. In stable-isotope studies in 32 young women, iron added to a European fresh cheese was absorbed at 20.5% to 28.7% when the cheese was eaten alone and at 6.9% to 8.4% when it came with bread and butter. That cheese was fortified with 2.5 mg of iron for the study, and plain queso fresco is not an iron source. Per 100 g the eight US samples also held about 14 g of saturated fat and no vitamin D.

Sources

1. qfr-daily-r4-11 · reference dataset
   Cheese, queso fresco, solid: Sodium 626.5 mg (range 462.0-759.0, 8 samples), Calcium 601.8 mg (552.0-713.0, 8 samples), Total lipid 23.36 g (20.46-26.81), Fatty acids total saturated 13.95 g (11.15-15.64) per 100 g
   USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-09-28
2. qfr-daily-r4-12 · reference dataset
   FNDDS 2705745 Queso Fresco, FNDDS code 14133000 - 1 slice 21 g, 1 oz 28 g, 1 cubic inch 18 g, 1 cup 135 g, Sodium 626 mg/100 g
   USDA FNDDS 2021-2023 · checked 2026-09-28
3. qfr-daily-r4-01 · randomized crossover trial
   True fractional Ca absorption from six foods was measured in twelve normal healthy women, aged 20-29 years. ... Mean fractional Ca absorption from the new fresh cheese was not significantly different from that from the traditional type (37.7 (SD 10.2)% v. 42.2 (SD 11.6)%).
   Br J Nutr, 1996 · checked 2026-09-28
4. qfr-daily-r4-02 · randomized crossover trial
   Geometric mean fractional iron absorption from fresh cheese fortified with iron-enriched yeast consumed alone was significantly lower than from the cheese fortified with FeSO4 (20.5 vs. 28.7 %; p = 0.0007). When the fresh cheese was consumed with bread and butter, iron absorption from both fortificants decreased to 6.9 % from the iron-enriched yeast compared to 8.4 % from ferrous sulfate.
   Eur J Nutr, 2017 · checked 2026-09-28
5. hf2-qfr-2 · agency advice
   Refrigerate newly purchased queso fresco-type cheeses in original unopened packaging as soon as possible and keep the cheeses at or below 40° F (4° C). Do not keep leftover queso fresco-type cheeses after they have been opened to minimize the risk of Listeria growth. ... If able, try to cook the queso fresco-type cheese as part of the dish, to a minimum internal temperature of 165° F (74° C).
   US FDA, Queso Fresco-type Cheeses Consumer Guidance (content current as of 01/16/2025) · checked 2026-10-08
6. qfr-daily-r4-06 · meta-analysis of prevalence studies
   Subgroup analysis showed that L. monocytogenes prevalence in raw milk (3.44%, 95% CI: 2.61%-4.28%) was significantly higher than in pasteurized milk (0.60%, 95% CI: 0.00%-2.06%).
   Foodborne Pathog Dis, 2024 · checked 2026-09-28
7. hf2-qfr-4 · agency outbreak summary
   The outbreak resulted in 12 hospitalizations, 2 pregnancy losses and 1 death in the United States. ... There were an additional 12 outbreaks of listeriosis in the U.S. during the period 1998‒2014 associated with soft cheeses made from pasteurized milk [1] . Most of these soft cheese outbreaks (8/12) were associated with QFT. Historical outbreaks of listeriosis have been associated with QFT made from unpasteurized milk, but recent outbreaks have been caused by cheeses made from pasteurized milk that was contaminated during the cheese-making process.
   US FDA, Summary of FDA's Strategy to Help Prevent Listeriosis Outbreaks Associated with Soft Fresh Queso Fresco-Type Cheeses (content current as of 03/20/2023) · checked 2026-10-08
8. hf2-qfr-7 · outbreak report
   The epidemiological investigation indicated that these two cases were associated with the consumption of Latin-style fresh cheese made from pasteurised milk in Portugal. Different batches of the same cheese were analysed and confirmed as contaminated with Listeria monocytogenes.
   Euro Surveill, 2012 · checked 2026-10-08
9. qfr-daily-r4-04 · case-control study
   Statistically significant risk factors in the final multivariate model were: eating cantaloupe [odds ratio (OR) 7·64], handling raw poultry (OR 4·88) and eating queso fresco (OR 7·11).
   Epidemiol Infect, 2016 · checked 2026-09-28
10. qfr-daily-r4-05 · prevalence survey
    Four (all Queso Fresco [QF] from retail markets) of 349 total samples tested positive for Listeria monocytogenes (Lm). ... The results of this study confirmed a 3.4% prevalence of Lm in QF collected from retail markets located in Sonora
    J Food Prot, 2007 · checked 2026-09-28
11. qfr-daily-r4-09 · policy statement
    However, the benefits of these natural factors have not been clearly demonstrated in evidence-based studies and, therefore, do not outweigh the risks of raw milk consumption. Substantial data suggest that pasteurized milk confers equivalent health benefits compared with raw milk, without the additional risk of bacterial infections.
    Pediatrics, 2014 · checked 2026-09-28
12. hf2-qfr-1 · agency advice
    Listeriosis outbreaks have been repeatedly linked to people eating queso fresco-type cheeses, therefore the FDA recommends that people vulnerable to listeriosis avoid eating all queso fresco-type cheeses. ... Most queso fresco-type cheeses sold by retailers are pasteurized. ... Although pasteurization is incredibly effective at eliminating Listeria , cheeses made with pasteurized milk can become recontaminated with Listeria if the manufacturing environment is unsanitary.
    US FDA, Queso Fresco-type Cheeses Consumer Guidance (content current as of 01/16/2025) · checked 2026-10-08
13. hf2-qfr-3 · agency advice
    Any unheated queso fresco-type cheeses, when made with pasteurized or unpasteurized (raw) milk, such as queso fresco, or similar fresh, soft cheeses such as queso blanco and requesón. ... Queso fresco-type cheeses or unpasteurized (raw) milk cheeses when heated to 165°F or until steaming hot
    CDC, Preventing Listeria Infection, table Safer Food Choices (last reviewed 01/16/2025) · checked 2026-10-08
14. hf2-qfr-5 · observational outbreak analysis
    Latin-style cheeses were implicated in 11/17 (65%) outbreaks, accounting for 98 (54%) cases of listeriosis. ... The proportion of listeriosis outbreaks linked to soft cheese made from pasteurized milk (12 outbreaks, 33%) was significantly higher during 2007–2014 than during 1998–2006 (1 outbreak, 5%; p = 0.009). ... However, some soft cheeses made with pasteurized milk, particularly Latin-style soft cheeses, have been produced in facilities with improper processing conditions, resulting in L. monocytogenes contamination.
    Emerging Infectious Diseases, 2018 (Jackson et al.) · checked 2026-10-08
15. hf2-qfr-6 · case-control study
    Seven (100%) cases but only 26 (60%) of 43 controls had consumed Mexican-style cheese in the month before illness (odds ratio, 5.89; 95% confidence interval, 1.07 to ∞; P = 0.04). Cultures of asadero cheese made from pasteurized milk collected at a manufacturing facility during routine sampling by the Michigan Department of Agriculture on 23 February 2009 yielded the outbreak strain
    J Food Prot, 2011 · checked 2026-10-08
16. qfr-daily-r4-03 · case-control study
    Eleven case patients were pregnant; infection with L. monocytogenes resulted in 5 stillbirths, 3 premature deliveries, and 3 infected newborns. ... queso fresco, a Mexican-style soft cheese (MOR, 7.3; 95% CI, 1.4-37.5)
    Clin Infect Dis, 2005 · checked 2026-09-28
17. qfr-daily-r4-07 · umbrella review
    We identified 397 citations of which nine systematic reviews comprising 330 studies and 487 patients' reviews were included. ... Listeriosis infections were likely to occur in the third trimester (66%) rather than in the first trimester (3%) of pregnancy.
    BJOG, 2022 · checked 2026-09-28
18. qfr-daily-r4-08 · pooled case analysis
    A longer incubation period was observed for pregnancy-associated cases (median: 27.5 days; range: 17-67 days) than for CNS cases (median: 9 days; range: 1-14 days) and for bacteraemia cases (median: 2 days; range: 1-12 days).
    BMC Infect Dis, 2013 · checked 2026-09-28
19. qfr-daily-r4-10 · agency guidance
    Pregnant women are about 10 times more likely to get listeriosis than other healthy adults.
    US FDA, Listeria (Listeriosis) food safety for moms-to-be, 2025 · checked 2026-09-28