We are all familiar with yummy blueberries, blackberries, and boysenberries… but have you heard of barberries?
Well, neither had I. Until now. It seems the barberry plant, including its tart red fruit, has traditionally been used in folk medicine for thousands of years, particularly in Iran and other Middle Eastern countries.
There are a number of impressive medicinal properties attributed to it, and I was quite excited to research it further. Some of the claims for barberry that I came across, online, include that it: fights infection, supports the gastrointestinal tract, improves heart health, combats the metabolic syndrome, cleanses the liver and gallbladder, and, most impressively, prevents and treats diabetes.
Table of Contents
- 1 Introduction
- 2 What Is Barberry?
- 3 Is There Any Research?
- 4 What Does the Research Reveal About Barberry?
- 5 Is Barberry Safe?
- 6 Conclusion
What Is Barberry?
Barberry (scientific name Berberis Vulgaris, abbreviated as B. Vulgaris) is considered the most widely known of a number of traditional medicinal plants from the genus Berberis. A common, deciduous garden bush, it is native to Europe and the British Isles, and naturalized in North America.
With yellow flowers and scarlet-colored fruit in the form of berries, various parts of this plant, including its root, bark, stem, leaf, and fruit, have traditionally been used in folk medicine (1,2). The biggest producer of B. vulgaris fruit in the world, with 11,000 hectares of land under cultivation, is Iran, where it is well known, both as a traditional medicine and a food (3).
Medicinal uses of barberry date back to over 3,000 years ago in Chinese medicine and to over 2,500 years ago in some other countries (2,3). Anthropologists “believe in a ritual practice or sacred object, especially by Native Americans, in its use as a supernatural power or as preventive or remedy of illness.” (2) It is the most widely used drug in the homeopathic system of medicine for kidney pain and for kidney stone removal (2).
Studies carried out on the chemical composition of the barberry plant show that its most important constituents are the isoquinoline alkaloids, namely berberine (BBR), but also berbamine and palmatine (1). Over twenty alkaloids, from various parts of the plant, have been already identified (2). BBR is one of the most studied among them.
A customary component in Chinese medicine, it is characterized by a diversity of pharmacological effects (4). In addition to the barberry plant, BBR is present in many other plants and is used for the treatment of different diseases (1).
Is There Any Research?
A PubMed search of the relevant search terms, for indexed articles available in the English language and specific to the human species, is discussed below in relation to some of the claims for barberry. Focusing consistently on meta-analysis papers and systematic reviews, which offer the most powerful information currently available, this is what I found.
[A systematic review answers a defined research question by collecting and summarizing all empirical evidence that fits pre-specified eligibility criteria. A meta-analysis is the use of statistical methods to summarize the results of these studies.]
A search for the terms “barberry,” “berberis vulgaris,” and “b.vulgaris,” retrieved just over three hundred PubMed-indexed articles. Of these, only twenty-eight are specifically relevant to the human species and, of these, only one is a systematic review (related to the management of arthritis symptoms). There are no meta-analyses available. Including non-human specific studies, there are still no published meta-analyses and only one further systematic review regarding cardiovascular disorders.
A search for BBR, Barberry’s most therapeutically revered constituent, offered much more promise. Over nine-hundred indexed-articles, relevant to humans, are available. Of these, five are meta-analyses and fourteen are systematic reviews. I will explore, below, whether any of these particular papers are able to verify some of the common claims for the barberry plant.
I am particularly impressed by the claim that the barberry plant is able to treat and prevent diabetes. Metformin is a medication commonly used to treat type 2 diabetes. With “metformin” as the sole search term, I found over nine thousand PubMed-indexed articles relevant to humans alone. Of these, three hundred are meta-analyses, and over six hundred are systematic reviews.
What Does the Research Reveal About Barberry?
Does It Cleanse the Liver or Gallbladder?
PubMed articles, published within the last decade, which can address this claim, are limited – I retrieved ten articles in total. There were neither systematic reviews nor meta-analyses among them, which makes it difficult to verify this particular claim. There is one recent review available. It discusses the potential mechanisms by which BBR treats non-alcoholic fatty liver disease (NAFLD).
It states, “Increase of insulin sensitivity, regulation of adenosine monophosphate-activated protein kinase pathway, improvement of mitochondrial function, alleviation of oxidative stress, LDLR mRNA stabilization, and regulation of gut microenvironment are the major targets of BBR in the treatment of NAFLD.” (5)
Of the remaining nine articles, one is based on a clinical trial, also looking at BBR and its effect on NAFLD, and is published in a respected journal (12). It concludes that “BBR ameliorates NAFLD and related metabolic disorders.” However, the trial included a fairly small sample size (one hundred and eighty-four eligible NAFLD patients, divided into three groups), the trial lasted a mere sixteen weeks, and it appears not to have been a blinded study (the “gold standard”).
Reviewing the remaining eight papers, they relate more to rat models and/or laboratory studies. Including non-human species studies in the search, there were more indexed articles overall. However, there still remained an absence of systematic reviews and meta-analyses to add any credibility to this claim.
Both the quantity and quality of research suggesting that barberry acts to cleanse the liver and/or gallbladder is lacking, and verifying the truth of this claim is difficult as a result.
Does It Help With Metabolic Syndrome?
Metabolic syndrome is a cluster of conditions that increase an individual’s risk of heart disease, stroke, and diabetes. They include high blood pressure, abnormal cholesterol levels, high blood sugar, and excess body fat around the waist/obesity.
Applying the search term “metabolic syndrome,” alone, I retrieved a mere twenty-four articles overall. Twelve relate to the human species specifically, with one being a meta-analysis of eleven randomized clinical trials. It doesn’t look at the effects of BBR alone, rather as a component of a nutraceutical combination, on the lipid profile of patients with high cholesterol (one aspect of the metabolic syndrome).
A significant effect was found for each of the lipid parameters – total cholesterol, LDL, HDL, and triglycerides. However, as BBR wasn’t studied in isolation, it’s hard to pinpoint its exact contribution, if any (6).
If we search for the individual conditions themselves, two further meta-analyses become available. One of those (7) reviewed eleven randomized, controlled trials, including a total of 874 participants, for the effect of BBR, specifically on blood lipids. It concluded that “BBR may have beneficial effects in the control of blood lipid levels.” However, it acknowledged, “The methodological quality of these studies was generally low,” and “more randomized controlled trials in a larger population of patients” were required to be conclusive.
The second one (8) analyzed the effect of BBR both on high blood pressure and abnormal cholesterol levels. Twenty-seven randomized controlled clinical trials were included with 2,569 patients. It had similar findings due to the “overall limited quality of the included studies.” Both are published in low-ranking journals.
Insulin resistance, a further component of the metabolic syndrome, is reviewed below, in the diabetes research section.
There is some low-quality, human-specific evidence that BBR may improve abnormal lipid levels and high blood pressure, two conditions characteristic of the metabolic syndrome. However, better quality research is needed to make conclusions regarding the general population.
What Does This Mean for You?
Having some barberries in your diet may potentially have an effect on elevated cholesterol and/or blood pressure levels. However, probably no more so than a healthy, high-fiber diet with plenty of fruits and vegetables, which has been well researched in benefiting our overall health.
Does It Improve Heart Health?
Applying the search terms “heart” and “cardiovascular,” I retrieved ninety indexed articles. Thirty-four of them are relevant to the human species, but there are no meta-analyses or systematic reviews amongst them. Including the entire ninety articles available, there are still no meta-analyses, but there is one recent (2017) systematic review.
It is a literature review of thirty-seven articles, published in the Iranian Journal of Basic Medical Sciences (which has a very, very low impact factor among peer-reviewed journals) and not specific to humans. Twelve studies examined the anti-hypertensive effects of B. vulgaris, seven studies investigated its anti-arrhythmic effects, while its inotropic and heart-protective effects were evaluated in four and eight studies, respectively.
They found that “B. vulgaris showed a beneficial effect in reducing blood pressure, enhancing cardiac contractility, and protection from reperfusion injury. However, the mechanisms of these effects are still under investigation.” They go on to state that it “could modify major risk factors for cardiovascular disorders, such as oxidative stress, hyperglycemia, and hyperlipidemia. Further studies are needed to translate these findings into effective cardiovascular medications.” (9)
Heart health is influenced by other conditions such as blood pressure and cholesterol levels. As covered under the claim above, regarding the metabolic syndrome, there is some low-quality evidence that BBR may improve abnormal lipid levels and high blood pressure (6, 7, 8).
This claim is difficult to verify, at this time, due to a lack of available, quality evidence suggesting that barberry improves heart health in humans. There is some evidence, albeit in low-ranking journals, that barberry offers some cardiovascular health benefits relating to its potential effects on blood pressure and blood lipid profile.
Does It Prevent or Treat Diabetes?
Here, I retrieved about one hundred and sixty indexed articles applying search terms “diabetes” and “insulin resistance.” Of these, about fifty are specific to the human species. Encouragingly, one of them is a recent (2015) meta-analysis and systematic review – a little less encouraging, the fact that it’s published in a journal with quite a low impact factor. It looks at the effect and safety of BBR in the treatment of type 2 diabetes (8). It concludes, “Due to overall limited quality of the included studies, the therapeutic benefit of BBR can be substantiated to a limited degree,” and, “Better methodological quality, large controlled trials using standardized preparation are expected to further quantify the therapeutic effect of BBR.”
One further meta-analysis and systematic review is available, covering fourteen randomized trials and including 1,068 participants (10). It concluded, similarly to above, that “the evidence of BBR for treating type 2 diabetes should be carefully interpreted due to the low methodological quality, small sample size, limited number of trials, and unidentified risks of bias.”
Minimal, low-quality evidence that barberry prevents or treats diabetes. As a result, this claim is difficult to substantiate at this time.
Does It “Aid the GI Tract”?
I found one notable article, a review of the actions and therapeutic implications of BBR in the gastrointestinal (GI) tract (13). It’s published in the American Journal of Chinese Medicine and summarizes the current knowledge in this area. “Binding and target sites, activated intracellular pathways, as well as the absorption and metabolism of BBR are discussed.”
However, there were neither meta-analyses nor systematic reviews to offer powerful conclusions towards this claim. I was also unable to source papers on clinical trials in this area. The search extended to non-human specific articles.
I was unable to locate quality evidence of a role for barberry in assisting the gastrointestinal tract, and so am not able to verify this claim.
Does It Fight Infection?
Similarly to the above claim, I retrieved a couple of articles in the context of this claim but, once again, no meta-analysis nor systematic reviews among them. Nor was I able to come across any quality clinical trials. Both human and non-human specific studies were considered. Both of the articles are related to laboratory-based studies on the Chlamydia pneumoniae infection and did conclude on some positive results.(14)
A lack of available quality evidence of a role for barberry in fighting infection makes this claim currently difficult to substantiate.
Is Barberry Safe?
With respect to BBR, it would appear so. In a meta-analysis of over 2,500 participants, “no serious side-effects” were noted (8). Similarly with a separate meta-analysis of over eight hundred participants (7) and yet another with just over one thousand participants (10).
One paper noted that “tolerability is high for low dosages, with some gastrointestinal complaints appearing to be associated with use of high dosages,” after some small, short-term clinical trials.(11)
It’s been truly fascinating to learn about the anecdotal healing history of this plant in certain parts of the world. The research on its most important constituent, BBR, is starting to build but, at this time, does not seem to support some of the more common online claims attributed to this plant.
Maybe this will change in the future, should better-quality studies be conducted. In the meantime, it’s the good old trusted blueberries and blackberries (and other berries, fruits, and vegetables) that will be finding their way into my morning smoothie.