Bacon and ham: a Group 1 label and no trial of either

The strongest study on this page is a meta-analysis of randomized trials, and it is not about health. Across 112 interventions in about 87,000 people, attempts to get people to eat less meat moved consumption by a standardized 0.07 (95% CI 0.02 to 0.12), rising to 0.25 where the target was red and processed meat alone. That is the only A-level evidence here. We found no trial that fed people bacon or ham as the tested food and measured what followed. The health numbers are observational. Pooling individual data from 1,966,444 adults in 31 cohorts over a median 10 years, each 1.8 oz (50 g) of processed meat a day went with 15 percent more type 2 diabetes (HR 1.15, 95% CI 1.11 to 1.20). Intake was reported by the participants themselves, and heterogeneity between cohorts ran near 59 percent. The International Agency for Research on Cancer places processed meat, which is what bacon and ham are, in Group 1, and puts colorectal cancer risk 18 percent higher for each 50 g eaten daily. Group 1 describes how sure the evidence is and not how large the effect is. The 18 percent is a relative increase, and no record on this page gives the baseline rate it is an increase on.

How much is actually in it

• Grilled back bacon holds 1,390 mg of sodium and 287 calories per 3.5 oz (100 g), while ham holds 800 mg and 107 calories, so the two cured meats sit far apart on both counts. — CoFID 2021 records for Bacon rashers, back, grilled, code 19-500 and Ham, code 19-496 (n = 2 composite records) Evidence E source
  Bacon 287 calories, fat 21.6 g, protein 23.2 g, sodium 1390 mg, chloride 2060 mg per 3.5 oz (100 g) against ham 107 calories, fat 3.3 g, protein 18.4 g, sodium 800 mg, chloride 980 mg

What a real portion looks like

• One regular slice of ham weighs 2.1 oz (60 g) in the USDA survey table and one slice of Canadian bacon 23 g, so a single slice of ham already passes the 50 g that the cancer agency counts. — USDA FNDDS household measures, Ham code 22311000 and Canadian bacon cooked code 22501010 Evidence E source
  Ham 60 g per regular slice, 90 g per thick slice, 135 g per cup, Canadian bacon 23 g per slice and 28 g per cooked ounce
• Between two Irish national surveys about a decade apart, the reported portion of bacon and ham did not change, while sliced ham on its own shrank. — Irish adults aged 18 to 64 in the North South Ireland Food Consumption Survey of 1997 to 2001 and the National Adult Nutrition Survey of 2008 to 2010, thirteen commonly consumed foods compared (n = two national surveys) Evidence C source
  No significant change for the category bacon and ham, a significant decrease for sliced ham, a significant increase for all cooked meat

What cooking and storage change

• Frying bacon destroys 55 percent of its thiamin and simmering cured ham 45 percent, while 90 to 100 percent of the sodium stays in the meat. — USDA Table of Nutrient Retention Factors Release 6, group Pork Products, method codes 1456 and 1522, table dated Sep-75 Evidence E source
  Bacon broiled or fried retains thiamin 45 percent, sodium 90 percent, iron 80 percent, cured ham simmered with drip retains thiamin 55 percent, vitamin B6 65 percent, sodium 100 percent
• A review of 69 food technology studies found only a few workable ways to make cured meat with less salt and less nitrite. — 69 articles on high-pressure processing and clean-label approaches in raw and processed meat published between 2018 and 2021, screened from 386 (n = 69 studies) Evidence D source
  Few advanced studies reporting effective low salt, low fat and reduced nitrite solutions for raw and cured meat, with high-pressure processing extending shelf life up to five times

What it does to your health

• In a 12-week randomized trial in 113 healthy adults, a meat-based diet raised DNA damage in fecal water by 15.97 percent, while the pesco-vegetarian arm did not move. — 113 healthy adults aged 18 to 50 randomized to a meat-based diet, a meat-based diet with alpha-tocopherol or a pesco-vegetarian diet for 12 weeks in free-living conditions, 103 completing (n = 113 randomized, 103 completed) Evidence B source
  Fecal water genotoxicity plus 15.97 percent DNA damage (95% CI 4.61 to 27.32, p = 0.006) on the meat-based diet, with no significant within-group change in the meat plus alpha-tocopherol arm or the pesco-vegetarian arm
• Pooling individual data from 1.97 million adults in 31 cohorts, every 1.8 oz (50 g) of processed meat a day went with 15 percent more type 2 diabetes over a median 10 years. — 1,966,444 adults aged 18 and over in 31 cohorts across 20 countries, 107,271 incident cases of type 2 diabetes over a median follow-up of 10 years (n = 1,966,444) Evidence C source
  HR 1.15 (95% CI 1.11-1.20) per 50 g per day of processed meat, HR 1.10 (1.06-1.15) per 3.5 oz (100 g) per day of unprocessed red meat, HR 1.08 (1.02-1.14) per 3.5 oz (100 g) per day of poultry
• Across 31 observational studies, processed meat eating went with 65 percent more colorectal polyps, while the link with adenomas did not reach significance. — 31 observational studies of meat subtypes and precancerous lesions of colorectal cancer published up to 31 December 2024 (n = 31 studies) Evidence C source
  Processed meat and colorectal polyps RR 1.65 (95% CI 1.05, 2.61), processed meat and colorectal adenomas RR 1.14 (0.93, 1.41), red meat and adenomas RR 1.13 (1.05, 1.21)

Safety, limits and interactions

• The International Agency for Research on Cancer places processed meat, which is what bacon and ham are, in Group 1, and puts the colorectal cancer risk at 18 percent higher for each 50 g eaten daily. — IARC Working Group of 22 experts from 10 countries reviewing more than 800 studies on red and processed meat Evidence E source
  Group 1, carcinogenic to humans, with an 18 percent higher colorectal cancer risk per 50 g of processed meat per day
• The FDA daily value for sodium is 2,400 mg, and 3.5 oz (100 g) of grilled back bacon covers more than half of it. — United States regulation, 21 CFR 101.74, health claims on sodium and hypertension Evidence E source
  Safe minimum 500 mg sodium per day and an upper level of 2,400 mg per day as the FDA Daily Value

What people believe that the data does not support

• In a randomized shopping experiment with 3,518 US adults, warning labels, a 30 percent tax and both together all cut the number of processed meat items picked, driven by processed pork. — 3,518 US adults randomized in October 2021 to control, warning labels, a 30 percent red meat tax or both in a naturalistic online grocery store (n = 3,518) Evidence B source
  Fewer processed meat items selected in all three intervention arms against control, with the reduction driven by processed pork
• In 3,338 UK adults, no cardiovascular biomarker differed across quartiles of nitrate from processed meats, except higher systolic pressure in the top quartile, which the authors report in contrast to their finding for nitrate from vegetables. — 3,338 adults aged 19 to 64 in the United Kingdom National Diet and Nutrition Survey years 1 to 8, with 4-day food diaries and clinic measurements (n = 3,338) Evidence C source
  No difference in cardiovascular biomarkers across quartiles of processed meat nitrate, with higher systolic pressure in Q4 at 1.8 to 3 mg per day against Q1 at 0.1 to 0.8 mg per day (P = 0.010)

Who this works differently for

• Pooling 15 studies of childhood leukemia, children who ate processed meat had 1.72 times the odds of acute leukemia. — 15 observational studies, 1 cohort and 14 case-control, of maternal and infant diet and acute leukemia in children under 18 (n = 15 studies) Evidence C source
  Processed meat in children OR 1.72 (95% CI 1.08, 2.72), vegetables OR 0.61 (0.39, 0.92), maternal fruit and acute lymphoid leukemia OR 0.71 (0.59-0.83)
• In 65 prospective studies of 831,798 women, eating red and processed meat before conception went with a higher risk of gestational diabetes. — 65 prospective studies with 831,798 participants on pre-pregnancy dietary intake and maternal or neonatal outcomes, 38 of them pooled (n = 831,798) Evidence C source
  Pre-pregnancy fried food, fast food, red and processed meat, heme iron and a low-carbohydrate pattern all positively associated with gestational diabetes, all P < 0.05

What is still unknown

• Across 112 randomized interventions in about 87,000 people, attempts to cut meat eating moved consumption by a standardized 0.07, and the subset aimed only at red and processed meat reached 0.25. — 35 papers comprising 41 studies and 112 interventions with approximately 87,000 subjects, each measuring meat and animal product consumption at least one day after the intervention (n = about 87,000) Evidence A source
  Pooled SMD 0.07 (95% CI 0.02 to 0.12) for all interventions, SMD 0.25 (95% CI 0.11 to 0.38) for those targeting red and processed meat only
• No trial in our corpus has fed people bacon or ham as the tested food, and no claim register in the United States or the European Union holds an entry for processed meat, cured meat or nitrite. — Layers searched on 2026-09-25 for bacon | ham and for the substances processed meat, cured meat and nitrite: USDA composition, CoFID, FNDDS, USDA retention R6, NHANES, 21 CFR 101, EU claim register, ODS, drug interaction layer, PubMed corpus version pubmed:468905 (n = 1 corpus record under the entity name) Evidence E source
  Zero absorption studies, zero US claims, zero EU claims, zero interaction entries for the three substances, and one single corpus record found under the paired name

The bottom line

Ham and bacon are not one food by the numbers. The UK composition table gives grilled back bacon 287 calories, 21.6 g of fat and 1,390 mg of sodium per 3.5 oz (100 g). Ham gets 107 calories, 3.3 g of fat and 800 mg of sodium. Both are composite records with no sample range, and the bacon row is British back bacon: no USDA record answers to this entity, so the American streaky cut has no second number here at all. The FDA Daily Value for sodium is 2,400 mg, so 100 g of that bacon covers more than half of a day. Portion is where the threshold bites. A regular slice of ham weighs 2.1 oz (60 g) in the US survey table, so one slice already passes the 50 g the cancer agency counts and a two-slice sandwich is more than twice it. A slice of Canadian bacon weighs 23 g there, and ordinary pork bacon has no row of its own, so for a rasher of the thing most people mean we have no weight at all. Between two Irish national surveys a decade apart the reported portion of bacon and ham did not change, while sliced ham on its own shrank, in two different samples of people rather than the same ones followed. Cooking takes the vitamins and leaves the salt. Frying destroys 55 percent of the thiamin in bacon and simmering 45 percent of it in cured ham, while 90 to 100 percent of the sodium stays in the meat. The retention table behind that is dated 1975 and works at the level of pork products rather than a brand. A review of 69 food technology studies found only a few workable routes to cured meat with less salt and less nitrite. That review is food technology: it measures what happens to the meat, not what happens to a person. In a 12-week randomized trial, 113 healthy adults aged 18 to 50 ate a meat-based diet, the same diet with alpha-tocopherol, or a pesco-vegetarian diet. DNA damage in fecal water rose 15.97 percent on the meat-based diet (95% CI 4.61 to 27.32, p = 0.006) and did not move in the pesco-vegetarian arm or in the arm eating the same meat with alpha-tocopherol. That is a biomarker over three months and not cancer, and the meat diet mixed red with processed meat instead of isolating bacon or ham. Across 31 observational studies, processed meat went with 65 percent more colorectal polyps (RR 1.65, 95% CI 1.05 to 2.61), while the link with adenomas did not reach significance (RR 1.14, 95% CI 0.93 to 1.41). Polyps and adenomas are precancerous lesions, not cancer. Who should be more careful. Two of the entries here are the cancer classification and the sodium limit, and the rest are about particular groups. Pooling 15 studies, 14 of them case-control, children who ate processed meat had 1.72 times the odds of acute leukemia (95% CI 1.08 to 2.72). Those are odds and not risk, the baseline rate is very small, and parents recalled the diet after the diagnosis was known. In 65 prospective studies of 831,798 women, red and processed meat eaten before conception went with more gestational diabetes, with direction and significance reported and no effect size given in the abstract, and with processed meat pooled alongside fried food and fast food. We found no drug interaction entry for processed meat, cured meat or nitrite in any register, and no record at all on the microbiological safety of ready-to-eat cured meat, which is a hole in this page and not a clean result. One belief is worth correcting. Nitrate from vegetables and nitrate from processed meat are not interchangeable. In 3,338 UK adults with 4-day food diaries, no cardiovascular biomarker differed across quartiles of nitrate from processed meat, except that systolic pressure was higher in the top quartile, 1.8 to 3 mg a day, than in the bottom at 0.1 to 0.8 mg (P = 0.010). The authors report that in contrast to what they found for nitrate from vegetables. The survey is cross-sectional, the meat dose at the top of the range is 3 mg a day, and nothing on this page measures the vegetable dose it is being set against. In a randomized online grocery experiment with 3,518 US adults, warning labels, a 30 percent tax and both together each cut the number of processed meat items chosen, driven by processed pork, in one hypothetical shopping trip rather than a year of eating.

Sources

1. bcnham-daily-r4-11 · reference dataset
   Bacon rashers, back, grilled, CoFID 19-500: Energy (kcal) 287 · Fat (g) 21.6 · Protein (g) 23.2 · Sodium (mg) 1390 · Chloride (mg) 2060 · Selenium (ug) 12 · Zinc (mg) 1.7; Ham, CoFID 19-496: Energy (kcal) 107 · Fat (g) 3.3 · Protein (g) 18.4 · Sodium (mg) 800 · Chloride (mg) 980 · Selenium (ug) 11 · Zinc (mg) 1.8
   CoFID 2021, Public Health England, codes 19-500 and 19-496 · checked 2026-09-25
2. bcnham-daily-r4-13 · reference dataset
   FNDDS 22311000 Ham: 1 regular/thin slice 60 g · 1 thick slice 90 g · 1 oz yields 20 g · 1 cubic inch 17 g · 1 cup 135 g; FNDDS 22501010 Canadian bacon, cooked: 1 slice 23 g · 1 oz cooked 28 g · 1 cubic inch cooked 18 g
   USDA FNDDS 2021-2023, codes 22311000 and 22501010 · checked 2026-09-25
3. bcnham-daily-r4-14 · cross-sectional survey comparison
   The analysis demonstrated that PS significantly increased for five foods ('white sliced bread', 'brown/wholemeal breads', 'all meat, cooked', 'poultry, roasted' and 'milk'), significantly decreased for three ('potatoes', 'chips/wedges' and 'ham, sliced') and did not significantly change for five foods ('processed potato products', 'bacon/ham', 'cheese', 'yogurt' and 'butter/spreads') between the NSIFCS and the NANS.
   Br J Nutr, 2015 · checked 2026-09-25
4. bcnham-daily-r4-12 · reference dataset
   USDA-RETN-R6:1456 BACON,BROILED/FRIED, group Pork Products: thiamin_mg 45% retained, calcium_mg 75%, iron_mg 80%, potassium_mg 85%, sodium_mg 90%, zinc_mg 100%; USDA-RETN-R6:1522 HAM/PICNIC,CURED,SIMMERED,W/DRIP: thiamin_mg 55% retained, vitamin_b6_mg 65%, folate_total_ug 70%, sodium_mg 100%, zinc_mg 100%
   USDA Table of Nutrient Retention Factors, Release 6, 2007, Retn_Codes 1456 and 1522 · checked 2026-09-25
5. bcnham-daily-r4-15 · systematic review of processing studies
   However, few advanced studies report effective and innovative solutions to develop low salt/fat, and reduced nitrite for raw and cured meat products.
   Food Res Int, 2021 · checked 2026-09-25
6. bcnham-daily-r4-02 · randomized trial
   FW genotoxicity increased significantly after MBD (+ 15.97%DNA damage; 95% CI 4.61 to 27.32; p = 0.006), with no significant within-group changes in MBD-T or PVD.
   Sci Rep, 2025 · checked 2026-09-25
7. bcnham-daily-r4-04 · meta-analysis of cohort studies
   Greater consumption of each of the three types of meat was associated with increased incidence of type 2 diabetes, with HRs of 1·10 (95% CI 1·06-1·15) per 100 g/day of unprocessed red meat (I2=61%), 1·15 (1·11-1·20) per 50 g/day of processed meat (I2=59%), and 1·08 (1·02-1·14) per 100 g/day of poultry (I2=68%).
   Lancet Diabetes Endocrinol, 2024 · checked 2026-09-25
8. bcnham-daily-r4-05 · meta-analysis of observational studies
   Processed meat consumption was correlated with increased colorectal polyp risk (1.65; 1.05, 2.61) but not colorectal adenoma risk (1.14; 0.93, 1.41).
   Nutr Rev, 2026 · checked 2026-09-25
9. bcnham-daily-r4-09 · agency classification
   Processed meat was classified as carcinogenic to humans (Group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer. ... Each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18%.
   IARC Press Release N 240, World Health Organization, 2015 · checked 2026-09-25
10. bcnham-daily-r4-10 · regulation
    Sodium is an essential nutrient, and experts have recommended a safe minimum level of 500 milligrams (mg) sodium per day and an upper level of 2,400 mg sodium per day, the FDA Daily Value for sodium.
    21 CFR 101.74, Health claims: sodium and hypertension · checked 2026-09-25
11. bcnham-daily-r4-03 · randomized trial
    Compared to control, all three interventions led participants to select fewer items with processed meat (driven by reductions in processed pork) and (for the tax and warning labels + tax interventions only) fewer items with unprocessed meat (driven by reductions in unprocessed beef).
    Int J Behav Nutr Phys Act, 2024 · checked 2026-09-25
12. bcnham-daily-r4-06 · cross-sectional study
    In contrast, there was no difference in CVD risk biomarkers across quartiles of nitrate intake from processed meats, with higher SBP in Q4 (1.8‒3 mg/d nitrate) than Q1 (0.1‒0.8 mg/d) (P = 0.010).
    J Nutr, 2026 · checked 2026-09-25
13. bcnham-daily-r4-07 · meta-analysis of observational studies
    Our results showed that children's consumption of processed meat was positively associated with AL (OR = 1.72; 95 % CI 1.08, 2.72), whereas the consumption of vegetables was found to be inversely associated with AL (OR = 0.61; 95 % CI % 0.39, 0.92).
    Clin Nutr ESPEN, 2025 · checked 2026-09-25
14. bcnham-daily-r4-08 · meta-analysis of observational studies
    With regard to maternal outcomes, pre-pregnancy intake of fried food, fast food, red and processed meat, heme iron and a low-carbohydrate dietary pattern was positively associated with the risk of gestational diabetes mellitus (GDM) (all P < 0.05).
    Crit Rev Food Sci Nutr, 2023 · checked 2026-09-25
15. bcnham-daily-r4-01 · meta-analysis of randomized trials
    We meta-analyze 35 papers comprising 41 studies, 112 interventions, and approximately 87,000 subjects. ... The pooled effect of all 112 interventions on MAP consumption is quite small (standardized mean difference (SMD) = 0.07 (95 % CI: [0.02, 0.12]), indicating an unsolved problem. Interventions aiming to reduce only consumption of red and processed meat were more effective (SMD = 0.25; 95 % CI: [0.11, 0.38]), but it remains unclear whether such interventions also decrease consumption of other forms of MAP.
    Appetite, 2026 · checked 2026-09-25
16. bcnham-daily-r4-16 · search record
    bacon | ham: USDA composition 0 records · CoFID 0 under paired name · FNDDS 0 · retention R6 0 · NHANES 0 ranked nutrients · corpus 1 record · corpus axis 2 query 0 of all types · 21 CFR 101 0 for processed meat, cured meat and nitrite · EU register 0 for processed meat, cured meat and nitrite · interactions 0 for processed meat and cured meat
    Bioma research layers, snapshot 2026-09-25 · checked 2026-09-25