Trans fat is liquid vegetable oil hardened with hydrogen — cheap, shelf-stable, made for shortening and fryer oil. It does one thing no other dietary fat does: it raises LDL cholesterol and lowers HDL at the same time. In the cleanest feeding trial, swapping olive oil for the same calories of trans fat raised LDL about 14 mg/dL and dropped HDL about 7 mg/dL 1. Calorie for calorie it moves the lipid panel toward heart disease about twice as hard as saturated fat 2.
This is one of the most settled findings in nutrition. Each two percent of daily calories from industrial trans fat tracked with a 23% higher rate of heart-disease events 3. Then the countries that banned it proved it: Denmark capped it in 2003 and cardiovascular deaths fell faster than in matched neighbours 4; New York counties that restricted it in restaurants saw heart-attack and stroke admissions drop an extra 6.2% 5. The FDA pulled its safe-to-add status in 2015 6.
Most of the win is already banked. A U.S. or EU shopper today eats maybe a quarter of the trans fat their parents did, and the marginal decade you'd gain by dragging that residual to zero is statistical, not felt. But the per-gram damage of what's left is still the largest of any fat in food, so any reduction sits at the top of the ranking. Three places it still reaches you: imported and street food, where roughly five billion people live in supplies with no enforceable ban 7; packaged goods that still list partially hydrogenated oil; and the rounding rule below.
There's no dose to take or test to order — three signals to catch on sight.
The fine print — when to skip it, and what people get wrong
"0 g means zero." No — three servings of a "0 g" product can total around 1.5 g, near the AHA's 2 g daily ceiling. If "partially hydrogenated" is on the list, the "0" is a rounding artefact.
"All trans fats are equally dangerous." The trace amount in dairy and beef shows no heart-disease signal at real-world doses 8. This avoid call is about the industrial source only; cutting milk and beef on trans-fat grounds isn't supported 9.
- 1Mensink RP, Katan MB (1990). Effect of dietary trans fatty acids on high-density and low-density lipoprotein cholesterol levels in healthy subjects. New England Journal of Medicine. link
- 2Mensink RP, Zock PL, Kester ADM, Katan MB (2003). Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials. American Journal of Clinical Nutrition. link
- 3Mozaffarian D, Katan MB, Ascherio A, Stampfer MJ, Willett WC (2006). Trans fatty acids and cardiovascular disease. New England Journal of Medicine. link
- 4Restrepo BJ, Rieger M (2016). Denmark's policy on artificial trans fat and cardiovascular disease. American Journal of Preventive Medicine. link
- 5Brandt EJ, Myerson R, Perraillon MC, Polonsky TS (2017). Hospital admissions for myocardial infarction and stroke before and after the trans-fatty acid restrictions in New York. JAMA Cardiology. link
- 6FDA (2015). Final Determination Regarding Partially Hydrogenated Oils. link
- 7WHO (2018). REPLACE Trans Fat: an action package to eliminate industrially-produced trans-fatty acids from the global food supply. link
- 8de Souza RJ, Mente A, Maroleanu A, et al. (2015). Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies. BMJ. link
- 9Bendsen NT, Christensen R, Bartels EM, Astrup A (2011). Consumption of industrial and ruminant trans fatty acids and risk of coronary heart disease: a systematic review and meta-analysis of cohort studies. European Journal of Clinical Nutrition. link
დაკავშირებული სახელმძღვანელოში (2)
- — An adjacent topic in the handbook.
- — An adjacent topic in the handbook.
Trans Fats
Avoidance is a label-reading habit: scan the ingredients list for 'partially hydrogenated oil' or 'shortening' and skip. In the post-FDA-enforcement (2018) U.S. and post-2021 EU food supplies, almost no mainstream products carry PHO any longer, so the habit triggers rarely. A trivial one-off pattern, not a sustained discipline.
Among the strongest evidence bases in nutritional epidemiology: the Mensink & Katan 1990 NEJM crossover and the Mensink 2003 60-trial meta-analysis lock the lipid mechanism; multiple independent cohort meta-analyses (de Souza BMJ 2015; Bendsen EJCN 2011) confirm CHD endpoints with industrial/ruminant separation; quasi-experimental population studies (Restrepo 2016; Brandt 2017) show CV mortality moving with regulation; AHA, FDA, WHO and EFSA guidelines converge (Sacks et al. Circulation 2017; FDA 2015; WHO REPLACE 2018).
Each 2% of energy from industrial trans fat is associated with roughly a 23% increase in incident CHD events in pooled cohort data (Mozaffarian et al. NEJM 2006); biomarker-based exposure measurement gives ~tripled CHD risk in highest vs lowest quartile (Sun et al. Circulation 2007). Quasi-experimental policy evaluations of the Danish ban (Restrepo & Rieger 2016) and NY State county restrictions (Brandt et al. JAMA Cardiology 2017) move CV mortality and MI/stroke admissions in the predicted direction. In 2026 regulated markets background exposure is well below 0.5% energy, so individual marginal benefit is smaller than at historical exposures, but the per-gram effect is the largest of any dietary fat and stays meaningful for readers with residual exposure (imported bakery, PHO still on ingredient lists, unregulated food supplies).