Citrus Bergamot: Effects on the Liver and Kidneys
Citrus bergamot, a fragrant fruit from Calabria in southern Italy, has moved from perfume and Earl Grey tea into the supplement aisle. Its polyphenol extracts are promoted for cholesterol and, increasingly, for liver health. Our editorial team reviews what is known about bergamot’s effects on the liver and kidneys, where the evidence is thin, and what safety issues to consider.
What citrus bergamot is
Bergamot (Citrus bergamia) is a citrus fruit grown predominantly along the Calabrian coast. Its peel oil flavours Earl Grey tea and is widely used in perfumery, while the juice and pulp are rich in flavonoids.
Supplements usually contain a bergamot polyphenol fraction (often abbreviated BPF) extracted from the juice. Key compounds include naringin, neohesperidin, neoeriocitrin and the unusual flavanone glycosides brutieridin and melitidin, which some researchers suggest have statin-like activity.
In the UK, bergamot extracts are sold as food supplements. They are not licensed medicines, and products cannot legally claim to treat or prevent disease or to lower cholesterol, since no such health claim is authorised.
Most of the research on bergamot comes from a relatively small number of Italian groups, which is worth bearing in mind when weighing the evidence.
Bergamot and the liver
Interest in bergamot and the liver grew from its effects on lipids and glucose. Mollace and colleagues reported reductions in cholesterol, triglycerides and blood glucose in both animal models and human participants taking bergamot polyphenols.
Because non-alcoholic fatty liver disease, now often termed metabolic dysfunction-associated steatotic liver disease (MASLD), is closely linked to these metabolic abnormalities, researchers explored whether bergamot might reduce liver fat. Gliozzi and colleagues reported improvements in liver fat assessed by ultrasound and in small dense LDL particles in people with metabolic syndrome taking bergamot polyphenols.
Animal studies suggest mechanisms such as activation of AMP-activated protein kinase, reduced fat synthesis in liver cells, antioxidant effects and reduced inflammation. These are plausible but not proven in humans.
A review by Perna and colleagues summarised the anti-inflammatory and antioxidant properties of bergamot and its potential cardiovascular applications, while noting that many trials were small, short and methodologically limited.
What about the kidneys?
Evidence on bergamot and the kidneys is much sparser. Most data come from rodent experiments in which bergamot extracts appeared to reduce markers of oxidative stress or kidney damage caused by toxins or metabolic disease.
There are no robust human trials showing that bergamot protects or improves kidney function. Statements in marketing about "kidney support" should therefore be regarded as speculative.
Indirect benefits are conceivable: improving blood pressure, glucose and lipids might reduce long-term kidney risk, as these factors drive chronic kidney disease. However, this remains theoretical for bergamot specifically.
People with existing kidney disease should be cautious with any supplement, because impaired kidney function can alter how compounds are cleared and some extracts contain potassium or other substances relevant to kidney health.
Safety and interactions
In short-term studies, bergamot polyphenol extracts have generally been well tolerated, with occasional reports of heartburn, digestive discomfort or muscle cramps.
| Issue | What is known | Practical step |
|---|---|---|
| Liver injury from supplements | Herbal and dietary supplements are a recognised cause of liver injury generally | Stop and seek advice if jaundice or dark urine develops |
| Statins and lipid drugs | Possible additive effects | Discuss with your prescriber |
| Drug metabolism | Some citrus compounds affect enzymes such as CYP3A4 | Ask a pharmacist about interactions |
| Bergamot essential oil | Contains bergapten, a phototoxic furanocoumarin | Do not ingest essential oil; supplements use juice extracts |
| Pregnancy and breastfeeding | Insufficient data | Avoid unless advised by a doctor |
Navarro and colleagues highlighted that herbal and dietary supplements are an increasingly recognised cause of drug-induced liver injury, and that product mislabelling and contamination contribute. While bergamot has not been strongly associated with liver injury, the general principle applies to any extract.
Grapefruit is famous for interacting with many medicines through furanocoumarins. Bergamot juice contains different compounds, but the possibility of interactions has not been fully explored, so caution is sensible for people on medicines with narrow therapeutic windows.
- Tell your GP or pharmacist about bergamot if you take statins, blood thinners, diabetes or blood pressure medicines.
- Have liver tests checked if you have known liver disease.
- Choose products with clear standardisation and reputable manufacturing.
Putting bergamot in context
For liver health, the most effective strategies for fatty liver are well established: gradual weight loss, regular physical activity, reducing alcohol and managing diabetes and blood pressure.
Bergamot may play a small supporting role for some people, particularly in lipid management, but it should not delay medical assessment or replace prescribed treatment.
If you are considering bergamot as an alternative to a statin, discuss it with your doctor. Prescribed lipid-lowering drugs have far stronger evidence for reducing heart attacks and strokes.
Monitoring helps: checking lipids and liver tests before and after a trial period gives objective information about whether it is worth continuing.
Conclusions of the editorial team
Citrus bergamot polyphenols show promise for blood lipids and possibly liver fat, but the evidence comes mostly from small studies by a limited number of research groups.
Data on the kidneys are almost entirely preclinical, so claims of kidney protection are unproven.
Bergamot extracts are generally well tolerated, but interactions and supplement quality warrant caution, and they are no substitute for proven treatments.
Related reading includes our articles on ezetimibe, on blood tests while taking essential phospholipids, and on ursodeoxycholic acid.
References
- Mollace V, Sacco I, Janda E, et al. Hypolipemic and hypoglycaemic activity of bergamot polyphenols: from animal models to human studies. Fitoterapia. 2011;82(3):309–316.
- Gliozzi M, Carresi C, Musolino V, et al. The effect of bergamot-derived polyphenolic fraction on LDL small dense particles and non alcoholic fatty liver disease in patients with metabolic syndrome. Adv Biol Chem. 2014;4:129–137.
- Perna S, Spadaccini D, Botteri L, et al. Efficacy of bergamot: from anti-inflammatory and anti-oxidative mechanisms to clinical applications as preventive agent for cardiovascular morbidity, skin diseases, and mood alterations. Food Sci Nutr. 2019;7(2):369–384.
- Navarro VJ, Khan I, Björnsson E, et al. Liver injury from herbal and dietary supplements. Hepatology. 2017;65(1):363–373.
- European Association for the Study of the Liver (EASL), European Association for the Study of Diabetes (EASD), European Association for the Study of Obesity (EASO). EASL–EASD–EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease. J Hepatol. 2016;64(6):1388–1402.
