Cheddar or feta: saltier, lighter, and the trials only cover one

In 164 adults over 50 who ate about 40 g of dairy fat a day for 6 weeks, LDL cholesterol ended at 115 mg/dL (2.97 mmol/L) when that fat came inside cheddar and at 133 mg/dL (3.43 mmol/L) when the same fat came as butter with casein and calcium. That shows the cheese structure matters. It does not show that cheese lowers cholesterol against eating none. Against a control diet, daily cheddar, a GABA-enriched test cheese, raised LDL by 5.8% over 6 weeks in 55 adults, and the comparison diets swapped in other fats. Every trial on this page used cheddar. We found no trial of feta, so the comparison rests on composition and on food safety surveys. Per 100 g in UK data, feta has more sodium (1000 against 723 mg), about half the calcium (360 against 739 mg) and less fat (20.2 against 34.9 g).

How much is actually in it

• Per 100 g, feta carries more sodium than cheddar (1000 vs 723 mg) but about half the calcium (360 vs 739 mg) and less fat (20.2 vs 34.9 g), in UK composition data. — CoFID records Cheese, Cheddar, English and Cheese, Feta Evidence E source
  Cheddar: 416 calories, fat 34.9 g, protein 25.4 g, calcium 739 mg, sodium 723 mg. Feta: 250 calories, fat 20.2 g, protein 15.6 g, calcium 360 mg, sodium 1000 mg

What a real portion looks like

• In US dietary survey portions, a slice of cheddar is 21 g and a wedge of feta 38 g, while a cup of crumbled feta weighs 5.3 oz (150 g). — FNDDS portion weights for Cheese, Cheddar (14104100) and Cheese, Feta (14104400) Evidence E source
  Cheddar: slice 21 g, stick 28 g, cup shredded 113 g. Feta: wedge 38 g, cup crumbled 150 g, cubic inch 17 g

What your body absorbs

• Vitamin D added to cheddar is absorbed as well as a supplement: weekly fortified cheddar raised blood 25(OH)D by 65.3 nmol/L over 8 winter weeks, versus 59.3 with drops. — 80 adults randomized to fortified cheeses, liquid supplement or placebo, 28,000 IU weekly for 8 weeks (n = 80) Evidence B source
  25(OH)D rise 65.3 (fortified cheddar), 69.4 (low-fat cheese), 59.3 nmol/L (supplement); not different from each other (P = 0.62)
• Cheddar delivers its protein more slowly than milk: in 24 young adults, 20 g of cheddar protein gave amino acids peaking at about 120 minutes and no insulin spike. — 24 young adults (12 men, 12 women), about 27 years, cheese vs protein-matched milk (n = 24) Evidence B source
  Branched-chain amino acids peaked about 120 min after cheese; insulin unchanged with cheese vs rapid spike at 20 min with milk

What cooking and storage change

• Melting changes cheddar's effect: eaten melted daily for 6 weeks, it raised total cholesterol by 7.7 mg/dL (0.20 mmol/L) and triglycerides by 15 mg/dL (0.17 mmol/L) more than the same cheese unmelted. — 162 overweight adults aged 50 and over, about 40 g dairy fat per day for 6 weeks (n = 162) Evidence B source
  Total cholesterol +0.20 plus or minus 5.8 mg/dL (0.15 mmol/L) and triglycerides +0.17 plus or minus 7.1 mg/dL (0.08 mmol/L) with melted vs unmelted cheese; no difference in LDL, HDL

What it does to your health

• Daily GABA-enriched cheddar for 6 weeks raised LDL cholesterol by 5.8% versus a control diet and by 7.0% versus a milk diet, in 55 adults. — 55 healthy adults with high-normal daytime blood pressure, three 6-week isoenergetic diets (n = 55) Evidence B source
  LDL +5.8% vs control and +7.0% vs milk diet; larger LDL particle size vs milk diet
• Adding cheddar to baked potato, pasta or toast lowered the meal's glycemic index to 39, 27 and 35, in a trial of 40 healthy adults. — 40 healthy adults (11 men, 29 women), Oxford (n = 40) Evidence B source
  Meal GI with cheddar: potato 39, pasta 27, toast 35
• Observational data link 15 g of cheese a day with a 5% lower risk of cardiovascular death (HR 0.95, 95% CI 0.91-0.99), but not with all-cause death, across 29 cohorts. — 29 prospective cohorts, 1,680,651 healthy adults, literature to June 2025 (n = 1680651) Evidence C source
  CVD mortality HR 0.95 (95% CI 0.91, 0.99) per 15 g/day cheese

Safety, limits and interactions

• Listeria monocytogenes was found in about 2.4% of soft cheese samples worldwide, the cheese category that includes feta, in a meta-analysis of 100 surveys. — 100 prevalence studies of deli meat, soft cheese and packaged salad, each with 100 or more samples (n = 100 studies) Evidence C source
  Prevalence in soft cheese 2.4% (95% CI 1.6 to 3.6%)
• In an Egyptian survey, Campylobacter was found in 14% of fresh Kareish cheese samples but in none of the feta samples. — 200 raw milk and cheese samples from Beni-Suef, Egypt (n = 200) Evidence C source
  Campylobacter in raw milk 18%, Kareish 14%, Talaga 6%, feta 0%
• A phase I study gave 12 men on a 6 mg/24 h selegiline patch about 400 mg of tyramine in aged cheeses to test cardiovascular safety. It does not cover oral MAO inhibitors. — 12 healthy men on selegiline transdermal 6 mg/24 h for 13 days, tyramine-enriched cheese meals (n = 12) Evidence C source
  Study aim only in the quoted sentence; outcome not quoted. Patch at 6 mg/24 h, not oral MAO inhibitors
• The FDA label for transdermal selegiline (EMSAM) warns that an MAOI combined with a high tyramine diet may cause a hypertensive crisis. — Adults using EMSAM (selegiline transdermal system) at 9 mg/24 h or 12 mg/24 h (n = -) Evidence E source
  Risk named: hypertensive crisis (label section 2.3)

What people believe that the data does not support

• The same dairy fat eaten inside cheddar gave lower cholesterol than eaten as butter plus casein and calcium: LDL 115 vs 133 mg/dL (2.97 vs 3.43 mmol/L) after 6 weeks in adults over 50. — 164 overweight adults aged 50 and over, about 40 g dairy fat per day for 6 weeks (n = 164) Evidence B source
  Post-intervention TC 5.23 vs 5.57 mmol/L and LDL 115 vs 133 mg/dL (2.97 vs 3.43 mmol/L), full-fat cheddar vs deconstructed components
• Observational data do not settle cheese and heart health: a 55-cohort meta-analysis found cheese alone showed inconsistent links with hypertension, heart disease and stroke. — 55 prospective cohort studies, literature to August 2020 (n = 55 studies) Evidence C source
  Inconsistent associations for cheese; total dairy RR 0.91 for hypertension (high vs low)

Who this works differently for

• Yogurt and cheese eaten before a meal cut pizza intake by 175 calories versus water, and older adults compensated for the dairy calories about half as well as young adults (33% vs 63%). — 30 older (60-70 y) and 28 young (20-30 y) adults, single pre-meal dairy loads (n = 58) Evidence B source
  Pizza intake -175 calories after yogurt and cheese vs water; compensation 33% in older vs 63% in young adults
• In 208 Taiwanese children with atopic dermatitis, specific IgE to cheddar cheese was one of the few lab values that tracked eczema severity. — 208 children up to 18 years with atopic dermatitis (n = 208) Evidence C source
  Cheddar-specific IgE associated with SCORAD (95% CI 1.814-16.731, P = .015)
• For people at higher risk of Listeria, CDC lists feta as a safer choice when it is made with pasteurized milk. — people at higher risk for Listeria: women who are pregnant, people 65 years or older, people with a weakened immune system Evidence E source
  String cheese, feta and mozzarella listed as a safer choice when made with pasteurized milk

The bottom line

Portions differ too. A US survey slice of cheddar weighs 21 g and a wedge of feta 38 g. Melting changed cheddar in one trial of 162 adults over 50. Eaten melted for 6 weeks, it raised total cholesterol by 7.7 mg/dL (0.20 mmol/L) and triglycerides by 15 mg/dL (0.17 mmol/L) more than the same cheese unmelted. Added to baked potato, pasta or toast, cheddar brought the meal glycemic index down to 39, 27 and 35 in 40 healthy adults, partly because fat and protein dilute the carbohydrate. Cheese and yogurt eaten before a meal cut pizza intake by 175 calories, and older adults made up for those calories less than young ones (33% against 63%). Fortified test cheddar raised blood vitamin D as well as drops over 8 winter weeks, while ordinary cheddar and feta contain little vitamin D. Observational data link 15 g of cheese a day with a 5% lower risk of cardiovascular death (HR 0.95, 95% CI 0.91-0.99) across 29 cohorts, with no link to death from all causes and no split by cheese type. A 55-cohort meta-analysis found the links between cheese and heart disease, stroke or hypertension inconsistent, so the question stays open. For safety, Listeria turned up in about 2.4% of soft cheese samples worldwide (95% CI 1.6 to 3.6%), with pasteurized and raw milk cheese not separated. For people at higher risk of Listeria, namely pregnant women, people 65 or older and people with a weakened immune system, CDC lists feta among safer choices only when it is made with pasteurized milk. In an Egyptian survey, Campylobacter appeared in none of 50 feta samples and in 14% of a local fresh cheese, a finding that says nothing about Listeria. Aged cheese limits apply to oral MAO inhibitor antidepressants, because of the tyramine in aged cheese such as mature cheddar. The FDA label for the selegiline patch EMSAM warns that MAOIs combined with a high tyramine diet may cause a hypertensive crisis. The one trial we hold tested only a low-dose selegiline patch in 12 healthy men, which says nothing about oral MAO inhibitors. In 208 Taiwanese children with eczema, IgE to cheddar tracked severity, an association that does not show eating it makes eczema worse.

Sources

1. chft-r5-01 · CoFID 2021, dataset
   CoFID 12-346 Cheese, Cheddar, English: Energy 416 kcal; Fat 34.9 g; Protein 25.4 g; Water 36.6 g; Calcium 739 mg; Sodium 723 mg per 100 g. CoFID 12-525 Cheese, Feta: Energy 250 kcal; Fat 20.2 g; Protein 15.6 g; Water 56.5 g; Calcium 360 mg; Sodium 1000 mg per 100 g
   CoFID 2021, Public Health England, OGL v3.0, codes 12-346 Cheese, Cheddar, English and 12-525 Cheese, Feta · checked 2026-10-02
2. chft-r5-02 · FNDDS, dataset
   FNDDS 14104100 Cheese, Cheddar (fdc 2705709): 1 slice 21 g; 1 stick 28 g; 1 cup, shredded 113 g; 1 cubic inch 17 g. FNDDS 14104400 Cheese, Feta (fdc 2705714): 1 wedge (1.33 oz) 38 g; 1 cup, crumbled 150 g; 1 cubic inch 17 g
   USDA FNDDS, food codes 14104100 Cheese, Cheddar and 14104400 Cheese, Feta (fdc 2705709, 2705714) · checked 2026-10-02
3. chft-r5-08 · Randomized controlled trial
   In the vitamin D-treated groups, the mean increases in 25(OH)D over 8 wk were: 65.3 +/- 24.1 (DC), 69.4 +/- 21.7 (DLF), 59.3 +/- 23.3 (DS+), and 59.3 +/- 19.6 nmol/L (DS-); these changes differed from the placebo groups (P < 0.0001) but not from one another (P = 0.62).
   J Nutr, 2008 · checked 2026-10-02
4. chft-r5-09 · Randomized crossover trial
   We found that cheese ingestion had a slower yet more sustained branched-chain amino acid circulation appearance over the postprandial period peaking at ~120 min.
   Nutrients, 2021 · checked 2026-10-02
5. chft-r5-03 · Randomized controlled trial
   Melted cheese increased total cholesterol concentrations by 0.20 ± 0.15 mmol L-1 and triglyceride concentrations by 0.17 ± 0.08 mmol L-1 compared to unmelted cheese.
   Food Funct, 2024 · checked 2026-10-02
6. chft-r5-05 · Randomized crossover feeding trial
   The cheese diet increased serum LDL-cholesterol concentrations compared with the control and milk diets (+5.8%, P = 0.006 and +7.0%, P = 0.0008, respectively) and increased LDL particle size compared with the milk diet (P = 0.02).
   Am J Clin Nutr, 2020 · checked 2026-10-02
7. chft-r5-07 · Randomized crossover trial
   In particular, the addition of cheddar cheese to potato, pasta and toast reduced the GI of the test meal to a value that is considered to be low-GI (39, 27 and 35, respectively).
   Eur J Clin Nutr, 2006 · checked 2026-10-02
8. chft-r5-10 · Meta-analysis of cohorts
   Cheese intake (15 g/day) was linked to a lower risk of CVD mortality only (HR: 0.95; 95% CI: 0.91, 0.99).
   Front Nutr, 2026 · checked 2026-10-02
9. chft-r5-12 · Meta-analysis of prevalence
   We included in the review 100 studies with a sample size restriction of ≥100, and we estimated L. monocytogenes prevalence in deli meat at 2.9% (95% confidence interval [CI], 2.3 to 3.6%), in soft cheese at 2.4% (95% CI, 1.6 to 3.6%), and in packaged salad at 2.0% (95% CI, 1.2 to 3.1%).
   J Food Prot, 2019 · checked 2026-10-02
10. chft-r5-13 · Prevalence study
    The highest prevalence was observed in milk samples (18%), followed by Kareish cheese (14%) and Talaga cheese (6%). In contrast, C. jejuni was not found in any of the Feta cheese samples.
    Foodborne Pathog Dis, 2021 · checked 2026-10-02
11. chft-r5-14 · Phase I challenge study
    The present study was conducted to determine the effect of the STS 6 mg/24 hour on cardiovascular safety following the ingestion of approximately 400 mg of tyramine consumed as a component of aged cheeses.
    CNS Spectr, 2007 · checked 2026-10-02
12. sf-tymaoi-4 · agency advice
    MAOIs including EMSAM combined with a high tyramine diet may cause a hypertensive crisis.
    EMSAM (selegiline transdermal system), FDA-approved label, sections 2.3 and 7.2 (Table 5) · checked 2026-10-08
13. chft-r5-04 · Randomized controlled trial
    However, a stepwise-matrix effect was observed between the groups for total cholesterol (TC) (P = 0.033) and LDL cholesterol (P = 0.026), with significantly lower postintervention TC (mean ± SD) (5.23 ± 0.88 mmol/L) and LDL cholesterol (2.97 ± 0.67 mmol/L) when all of the fat was contained within the cheese matrix (Group A), compared with Group C when it was not (TC: 5.57 ± 0.86 mmol/L; LDL cholesterol: 3.43 ± 0.78 mmol/L).
    Am J Clin Nutr, 2018 · checked 2026-10-02
14. chft-r5-11 · Meta-analysis of cohorts
    Milk, cheese, or yogurt consumption showed inconsistent associations with the cardiovascular outcomes in high compared with low intake and dose-response meta-analyses.
    Adv Nutr, 2022 · checked 2026-10-02
15. chft-r5-06 · Randomized crossover trial
    Pizza intake was reduced by 175 kcal after yogurt and cheese and by 82 kcal after milks compared to water (P < 0.001). ... Compensation was less in older (33%) than in young (63%) adults (P < 0.03).
    J Nutr, 2021 · checked 2026-10-02
16. chft-r5-15 · Observational study
    Serum IgE values and a number of specific IgE that are positive significantly different SCORAD index through simple linear regression; however, after multiple linear regression, only IgE values (95% CI: 0.001-0.004, P < .001), total WBC count (95% CI: 0.112-1.736, P = .026), EC (95% CI: 0.045-6.706, P = .047), and specific IgE to Cheddar cheese (95% CI: 1.814-16.731, P = .015) remain different.
    Medicine (Baltimore), 2020 · checked 2026-10-02
17. sf-lsc-r3-cheddarfeta-1 · agency advice
    Cottage cheese, cream cheese, string cheese, feta, and mozzarella, when made with pasteurized milk
    Preventing Listeria Infection, Centers for Disease Control and Prevention, Safer Food Choices · checked 2026-10-08