Ketchup: the salt is measured, the tomato science is borrowed

Almost everything said about ketchup and health was measured on something else. We found no trial that fed people ketchup. The studies behind this page used tomato puree, sauce, paste and soup, and some used lycopene supplements (lycopene is the red pigment in tomatoes). Ketchup inherits those results only because it is made of tomatoes. What was measured on ketchup itself is plainer. A 17 g tablespoon carries about 158 mg of sodium, and restaurant ketchup averaged 949 mg per 100 g across 46 USDA samples. The UK composition table lists 27.5 g of sugar per 100 g, which by our own arithmetic comes to about 4.7 g in a 17 g tablespoon. In a survey of 233 sauces in Malaysian supermarkets, not one tomato ketchup met the UK salt target. The strongest tomato evidence is also the least exciting. A meta-analysis of 34 trials found that tomato products and lycopene had no significant effect on blood lipids (triglycerides, total cholesterol and LDL cholesterol).

The numbers, per 100 g

How much is actually in it

• In a 2017 survey of 233 sauces in Malaysian supermarkets, no tomato ketchup and only 21.7% of chilli ketchups met the UK salt targets. — 233 sauces from seven major supermarkets in Kuala Lumpur, label data (n = 233) Evidence C source
  0% of tomato ketchups and 21.7% of chilli ketchups below 2017 UK salt guidelines
• Restaurant ketchup holds 949 mg sodium per 100 g in USDA Foundation data, ranging 878 to 1030 mg across 46 samples, while the UK CoFID tomato ketchup lists 800 mg. — USDA Foundation Foods sample set and UK CoFID 2021 composition table (n = 46 samples (USDA)) Evidence E source
  Sodium 949 mg/100 g (878-1030, n=46) USDA vs 800 mg/100 g CoFID, total sugars 27.5 g/100 g CoFID

What a real portion looks like

• In 21 adults eating fries and brownies with ketchup and other condiments on offer, adding ketchup lifted how much they liked the fries and led to extra fries eaten in one sitting. — 21 subjects, ad libitum meals of fries then brownies under three conditions (n = 21) Evidence C source
  Hedonic ratings for fries rose after ketchup was introduced, leading to additional intake of fries (size not in the quoted sentence)
• A US tablespoon of ketchup weighs 17 g and carries about 158 mg of sodium, a 10 g packet about 93 mg, while reduced-sodium ketchup lists 20 mg per 100 g. — US household measures, FNDDS (n = FNDDS 5,432 foods) Evidence E source
  1 tablespoon 17 g 157.8 mg sodium, 1 packet 10 g 92.8 mg, dipping container 28 g 259.8 mg, reduced sodium 20 mg/100 g

What your body absorbs

• In 10 healthy adults, adding 500 mg of calcium carbonate to a tomato paste meal cut lycopene bioavailability by 83 %. — 10 healthy adults, single test meal with 19 mg lycopene from tomato paste, randomised crossover (n = 10) Evidence B source
  Lycopene bioavailability down 83 % with 500 mg calcium carbonate in the meal
• Across 12 RCTs, eating carotenoid foods with fat rich in unsaturated fatty acids raised carotenoid absorption more (SMD 0.90) than fat rich in saturated fatty acids (SMD 0.27). — 12 RCTs and 27 in vitro studies of carotenoid absorption with different dietary fats (n = 12 RCTs) Evidence A source
  SMD 0.90 (95% CI 0.69 to 1.11) unsaturated vs SMD 0.27 (95% CI 0.08 to 0.47) saturated fats

What cooking and storage change

• In 10 women given 16.5 mg of lycopene a day, plasma lycopene rose more from tomato puree than from the same lycopene dose in raw tomato, both after one portion and over 7 days. — 10 healthy women, single portions and 7 days of daily portions with 16.5 mg lycopene (n = 10) Evidence B source
  Plasma total lycopene higher after puree than raw tomato (P < 0.025 single dose, P < 0.01 daily for 7 days)
• In 12 adults, a tomato sauce rich in cis-lycopene gave a 54 % larger lycopene response than an all-trans-rich sauce (7.30 vs 4.74 nmol x h/l). — 12 healthy adults, 150 g sauce in a standard breakfast, randomised crossover with 2-week washouts (n = 12) Evidence B source
  Dose-adjusted lycopene AUC 7.30 vs 4.74 nmol x h/l, P = 0.002

What it does to your health

• A 2023 meta-analysis of 34 RCTs found that lycopene and tomato intake had no significant effect on triglycerides, total cholesterol or LDL cholesterol. — adults in 34 randomised trials of lycopene supplements or tomato products (n = 34 RCTs) Evidence A source
  No significant effect on TG, TC or LDL-C (other outcomes not in the quoted abstract sentence)
• In 11 RCTs in people with overweight or obesity, tomato-based products trimmed waist circumference by 1.15 cm on average, with no consistent change in body weight or BMI. — adults with mean BMI 25 kg/m2 or more, 11 RCTs of tomatoes, tomato products or extracts (isolated lycopene excluded) (n = 11 RCTs) Evidence A source
  Waist MD -1.153 cm (95% CI -2.27 to -0.04)
• Observational data from 30 studies link cooked tomatoes and sauces with a 16 % lower prostate cancer risk (RR 0.84), while raw tomatoes showed no association (RR 0.96). — 30 studies, 24,222 prostate cancer cases among 260,461 participants (n = 260461) Evidence C source
  Cooked tomatoes and sauces RR 0.84 (0.73 to 0.98), raw tomatoes RR 0.96 (0.84 to 1.09)
• In 20 women, 55 g of tomato paste in olive oil daily for 12 weeks raised the UV dose needed for measurable redness from 23 to 36.6 mJ/cm2 compared with olive oil alone. — 20 healthy women aged 21-47, skin phototype I/II, 12 weeks (n = 20) Evidence B source
  Erythemal D30 36.6 vs 23 mJ/cm2 (P = 0.03), minimal erythema dose not significantly different

Safety, limits and interactions

• Seven children with widespread, stubborn dermatitis improved by 60-80% after a diet low in balsam of Peru chemicals that mainly cut out ketchup. — 7 children with systemic allergic contact dermatitis linked to balsam of Peru (n = 7) Evidence C source
  60-80% clearance of dermatitis after the diet change

Who this works differently for

• In 33 men awaiting prostatectomy, daily tomato sauce (142 to 198 g) raised prostate lycopene 3.6-fold over a lycopene-restricted control diet. — 33 men scheduled for prostatectomy, randomised to control, tomato soup, sauce or vegetable juice with 25-35 mg lycopene a day (n = 33) Evidence B source
  Prostate lycopene 3.5-fold (soup), 3.6-fold (sauce), 2.2-fold (juice, not significant) vs 0.16 nmol/g in controls

What is still unknown

• A 2022 scoping review found only 12 studies on how industrial processing changes tomato nutrients, with inconsistent results and no simple answer on whether processed products match fresh tomatoes. — 12 original food composition studies of industrial tomato processing (n = 12) Evidence D source
  No consistent direction across compounds and processing methods

The bottom line

Treat ketchup as a salty condiment and pick the portion on purpose. A 10 g packet carries about 93 mg of sodium and a 28 g dipping cup about 260 mg. Reduced-sodium ketchup lists 20 mg per 100 g, so if salt is the thing you watch, that label is the simplest switch on the shelf. Ketchup may also change how much else you eat. In one small study of 21 adults, putting condiments on the table with fries and brownies made the fries taste good again once people had started to tire of them, and adding ketchup led to extra fries eaten in that one sitting. That was one meal in a lab, and nobody has checked what happens over weeks. On the tomato side, two small trials looked at the form the lycopene comes in. Tomato puree raised blood lycopene more than raw tomato at the same dose. A sauce rich in cis-lycopene gave a 54 percent larger response than one rich in all-trans lycopene (cis and all-trans are two shapes of the same pigment molecule). Across 12 trials, carotenoids went in better with unsaturated fat than with saturated fat. One thing works against it. In 10 healthy adults, 500 mg of calcium carbonate added to a tomato paste meal cut lycopene uptake by 83 percent. That trial measured lycopene from a single meal and nothing else, so it is no reason to change calcium you have been prescribed. Whether any of this matters for your health is the open part. Across 30 observational studies, cooked tomatoes and sauces went with a 16 percent lower risk of prostate cancer and raw tomatoes with none. Studies of that kind cannot show that the tomatoes caused the difference. In a trial of 33 men awaiting prostate surgery, tomato sauce raised lycopene in the prostate 3.6-fold, and they ate 142 to 198 g of sauce every day. A tablespoon of ketchup is 17 g. Trials of tomato products in people with overweight took 1.15 cm off the waist on average, with no reliable change in weight, and some of those trials used extracts. In 20 fair-skinned women (skin phototype I or II, the kind that burns easily), 55 g of tomato paste a day in olive oil for twelve weeks made the skin need a larger UV dose before it reddened. That was tomato paste with far more lycopene than a ketchup serving, and the second redness measure in the same trial did not move. On safety our evidence is thin. The only card is a case series of seven children with a stubborn rash tied to an allergy to balsam of Peru, whose skin cleared by 60 to 80 percent on a diet that mainly cut out ketchup. Seven cases with no comparison group are worth knowing about and too few to build a rule on, and if your child has that diagnosis it is a question for the dermatologist. We hold no card that links ketchup's salt or sugar to blood pressure, kidneys, weight or teeth, and nothing on pregnancy, children in general or medicines, so this page cannot tell you who else should be careful. Even the basic question of whether factory processing leaves a tomato product as good as fresh tomatoes rests on 12 studies that disagree with each other.

Sources

1. ktch-b4-10 · cross-sectional survey
   only 21.7% of chilli ketchup and no tomato ketchup were below the 2017 UK salt guidelines.
   BMJ Open, 2019 · checked 2026-09-23
2. ktch-b4-14 · reference dataset
   FDC 747693 Ketchup, restaurant: Sodium, Na 949 mg/100 g, range 878-1030, n=46 · CoFID 17-709 Tomato ketchup: Sodium 800 mg, Total sugars 27.5 g, Energy 115 kcal per 100 g
   USDA FoodData Central Foundation Foods 2026-04-30 and CoFID 2021, Public Health England / OGL v3.0 · checked 2026-09-23
3. ktch-b4-12 · feeding experiment
   In the "successive" situation, hedonic ratings for fries diminished during intake but increased after the introduction of ketchup, leading to additional intake of fries.
   Physiol Behav, 2009 · checked 2026-09-23
4. ktch-b4-15 · reference dataset
   FNDDS 2709733 Ketchup: Sodium 928 mg/100 g · 1 tablespoon 17 g 157.8 mg · 1 packet 10 g 92.8 mg · 1 dipping-size container 28 g 259.8 mg · FNDDS 2709734 Ketchup, reduced sodium: Sodium 20 mg/100 g
   USDA FNDDS 2021-2023 · checked 2026-09-23
5. ktch-b4-01 · randomised crossover trial
   LYC bioavailability was diminished by 83 % following the addition of Ca in the test meal.
   Br J Nutr, 2016 · checked 2026-09-23
6. ktch-b4-04 · meta-analysis of RCTs
   fats rich in unsaturated fatty acids resulted in greater improvement in carotenoid bioavailability (SMD 0.90; 95%CI, 0.69-1.11) as compared with fats rich in saturated fatty acids (SMD 0.27; 95%CI, 0.08-0.47).
   Nutr Rev, 2022 · checked 2026-09-23
7. ktch-b4-02 · randomised trial
   Plasma total lycopene concentration was higher after the tomato purée intake than after the raw tomato in both the first (F(1,8) 7.597; P < 0.025) and the second experiments (F(1,8) 12.193; P < 0.01) demonstrating a significant effect of food matrix on absorption.
   Br J Nutr, 1998 · checked 2026-09-23
8. ktch-b4-03 · randomised crossover trial
   AUC values adjusted for the amount lycopene consumed showed that total, total cis-, and all-trans-lycopene responses were significantly higher from the cis-isomer-rich sauce, compared with the all-trans-rich sauce, being 7.30 (sem 1.45) v. 4.74 (sem 1.08) nmol x h/l (P = 0.002)
   Br J Nutr, 2007 · checked 2026-09-23
9. ktch-b4-05 · meta-analysis of RCTs
   a total of 34 studies met the eligibility criteria and were included in this meta-analysis ... lycopene and tomato consumption did not have significant effects on other cardiovascular risk factors such as triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C)
   Curr Pharm Des, 2023 · checked 2026-09-23
10. ktch-b4-06 · meta-analysis of RCTs
    In the RCTs, tomato-based interventions produced a small but significant reduction in waist circumference (MD: -1.153 cm, 95% CI: -2.27 to -0.04, p = 0.0432), with no consistent effects on body weight or BMI.
    Food Funct, 2026 · checked 2026-09-23
11. ktch-b4-07 · meta-analysis of observational studies
    cooked tomatoes and sauces (RR = 0.84, 95% CI: 0.73-0.98, p = 0.029) were associated with a reduced risk of PCa ... no associations were found for raw tomatoes (RR = 0.96, 95% CI: 0.84-1.09, p = 0.487)
    Prostate Cancer Prostatic Dis, 2018 · checked 2026-09-23
12. ktch-b4-09 · randomised controlled trial
    Mean ± SD erythemal D(30) was significantly higher following tomato paste vs. control (baseline, 26·5 ± 7·5 mJ cm(-2); control, 23 ± 6·6 mJ cm(-2); tomato paste, 36·6 ± 14·7 mJ cm(-2); P = 0·03), while the MED was not significantly different between groups
    Br J Dermatol, 2011 · checked 2026-09-23
13. ktch-b4-11 · case series
    We present seven children with widespread, recalcitrant dermatitis who experienced 60-80% clearance after initiating a diet low in balsam of Peru, specifically the tomato product ketchup.
    Pediatr Dermatol, 2013 · checked 2026-09-23
14. ktch-b4-08 · randomised controlled trial
    The end-of-study prostate lycopene concentration was 0·16 (sem 0·02) nmol/g in the controls, but was 3·5-, 3·6- and 2·2-fold higher in tomato soup (P= 0·001), sauce (P= 0·001) and juice (P= 0·165) consumers, respectively.
    Br J Nutr, 2015 · checked 2026-09-23
15. ktch-b4-13 · scoping review
    Twelve original research papers were found to study the effects of different industrial processing methods on the nutrients and/or bioactive compounds in tomato products ... currently available data are still limited, and the existing data are often inconsistent.
    Adv Nutr, 2022 · checked 2026-09-23