Blueberry Leaf

August 10, 2009 Written by JP    [Font too small?]

The fruit of the tree is what first catches the eye. Then the mind begins to anticipate the satisfyingly sweet flavor and fragrant scent that is unique to fresh ripened fruit. However, it’s pretty rare that we ponder the intrinsic value of the other parts of bushes, plants and trees. Without leaves, roots and stems there would obviously be no fruit to bear, but that’s about as much consideration as most non-botanists give to this topic. Fortunately, research scientists are a different breed. They look at the same tree and wonder about the chemical make up of all the inedible parts. They understand that the next big breakthrough in the management of cancer, diabetes, heart disease or virtually any health condition may be found in the less conspicuous regions of the natural world.

The next time you browse around your local health food store, keep an eye out for blueberry leaf extract. You read that correctly – leaf extract. In recent years, much acclaim has been bestowed upon blueberries. This is completely justified. The tiny purple gems are, without question, one of the most health supportive foods available. But what is not commonly known is that the leaves of the blueberry bush also provide separate and distinctive advantages over the fruit.

In 1927 a correspondence was printed in the Canadian Association Medical Journal. It describes the early stages of testing on a new diabetes “drug” derived from blueberry leaf. The results of those early experiments were mixed at best. But the beautiful thing about science is that a temporary failure or setback doesn’t necessarily mean that an entire line of study needs to be abandoned. In the latter part of the 20th century, researchers began to better understand how and why blueberry leaf extracts could aid diabetics and others with blood sugar disorders. (1,2)

The key to discovering the relevance of these therapeutic leaves was to first determine what they’re made of. Laboratory work determined that the leaves of the blueberry bush are significantly richer in antioxidant content (phenolics) than the berries themselves, giving them a greater ability to counteract damaging free radicals (ORAC). (3,4)

The leaves were also found to contain certain phytochemicals, such as chlorogenic acid and myricetin. These and other naturally occurring “plantioxidants” are known to possess a broad spectrum of anti-diabetic properties. (5,6,7,8,9,10,11,12) Some of the mechanisms by which they work include: decreasing sugar production in the liver and reducing sugar uptake in the intestines, inhibiting the digestion of carbohydrates, protecting insulin producing cells in the pancreas and supporting insulin sensitivity. (13,14,15) In addition, it appears that these very same antioxidants help reduce some of the cellular harm that is a common consequence of diabetes. One example is demonstrated with regard to Advanced Glycation End products (AGE). These are detrimental substances that are generally more pronounced in diabetics and likely contribute to the development of chronic inflammation, heart disease, neuropathy (nerve pain) and retinopathy (eye damage). (16,17)

Properly managing blood sugar levels helps diabetics ensure a healthier heart and protects against many chronic health conditions associated with the disease. The same is true for the population at large. If I were to describe one of the healthiest changes most people could make, it would be this: Live your life as though you had diabetes. Eat a diet that prevents wild blood sugar fluctuations, exercise regularly, maintain a healthy weight and practice stress management. To that list, you may want to consider adding blueberry leaf extract – especially if you’re concerned about your cardiovascular status.

In 2006, a 4 week study was conducted on 42 middle-aged diabetics. Half were given a blueberry leaf extract (300 mg three-times daily). The remainder received an inactive placebo. The respective “medications” were taken 15-30 minutes prior to each meal. Significant improvements were only found in the blueberry leaf users. A 27% reduction in fasting blood glucose and an almost 60% decline in C-Reactive proteins were noted. A number of markers associated with diabetic wellness and liver health also showed signs of improvement (plasma enzymes ALT, AST & GGT). Several other experiments have found similar results in animal models of diabetes. These trials also indicate a potential hypotensive (blood pressure lowering) and triglyceride normalizing effect. (18,19,20,21)

Source: Georgian Med. News 2006 Dec;(141):66-72 (link)

The future appears to be quite bright for blueberry leaf extract (BLE). This past month, a study published in the Journal of Biological Chemistry found that a concentrated and purified form of blueberry leaf could prevent the replication of the Hepatitis C virus. This is great news for the nearly 200 million people worldwide who have chronic Hepatitis C – a slow progressing, infectious liver condition that can lead to cirrhosis (liver scarring), liver cancer and/or liver failure. (22,23) There’s even some evidence that suggests applications for BLE in the field of cancer research. Preliminary research hints at BLE’s potential in the management of colorectal, liver, lung and ovarian cancer and perhaps even leukaemia. (24,25,26,27,28)

In the years to come, it wouldn’t surprise me to read reports about other neglected plant parts that are “discovered” to possess truly wondrous healing properties. Out of curiosity, I did a brief search of the medical literature on “strawberry leaves” and found that they too have a lot to offer. It seems as though they might one day be used to help promote healthier circulation in those with heart disease. In fact, a brand new study determined that strawberry leaves had a very similar affect as the tried and true natural heart remedy, hawthorn extract. Additional scientific inquiries into both blueberry and strawberry leaves are sure to come. I’m thankful for that and I hope that aspect of human inquisitiveness will never end. (29,30,31)

Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!

Be well!

JP


Tags: , ,
Posted in Diabetes, Heart Health, Nutritional Supplements

16 Comments & Updates to “Blueberry Leaf”

  1. sai Says:

    Wow..27% decrease in fasting blood glucose would make all the difference. I have the same exact problem where the liver produces the sugar (along with metabolic syndrome) and this is a Great news. Thanks for sharing this vital information. Great Post as always.

    Best Regards

    Sai

  2. sai Says:

    JP

    Checked and not many blueberry leaf extract, will keep checking, Thanks again

    Best Regards

    Sai

  3. JP Says:

    Sai,

    I’m happy that the information was of interest.

    It’s not a very common supplement at this time. Hopefully that will change in the near future. I’ve noticed that some major US (supplement) manufacturers such as Solgar, Solaray and Swanson Vitamins do have encapsulated extracts available (standardized for chlorogenic acid content).

    I’ve also seen some blueberry leaf teas around as well. Alvita is one US tea manufacturer that sells such a product.

    PS – I’ve covered the topic of metabolic syndrome quite often since starting this site. It’s a major health issue and one that I take very seriously. I hope some of that information will help you to overcome it.

    Be well!

    JP

  4. Ana Says:

    I found this article quite informative. I am having a bit of difficulty finding the extract but I will keep looking.
    Thank you for sharing this important info.

    Ana

  5. JP Says:

    Thank you, Ana. Please see my response to Sai’s question above. I mentioned at least three prominent manufacturers that carry a blueberry leaf extract – Solaray, Solgar and Swanson Vitamins.

    I hope that helps!

    Be well!

    JP

  6. Jeffrey Fried Says:

    The form of blueberry leaf extract required to positively impact hepatitis C requires a new extraction method. It is not clear that current extracts will work.

  7. JP Says:

    Thank you, Jeffrey

    Here’s a link for anyone who’s interested in the research supporting that assertion:

    http://www.jbc.org/content/284/32/21165.long

    Be well!

    JP

  8. Rick Says:

    I can definitely vouch for blueberry leaf as an aid to blood sugar control. I have cut back on herbals for now because I am concerned that polyphenols *may* have contributed to my decline in iron stores. But when I was taking several about 5-15 minutes before each meal, I think the blueberry leaf was the most powerful aid to sugar control. Originally I was taking a Solgar gelcap, but found that Puritan’s Pride has a softgel version that is both less expensive and smaller — so it is easier to carry to work or a restaurant. (Vitamin World, which I believe is co-owned, has an identical product, but with it’s continual BOGOs Puritan is more economical.)

    Anyway, I wholeheartedly endorse Blueberry Leaf. If you’re taking a lot of herbals and/or bioflavanoids like Quercetin (which was also part of my pre-meal regimen), be sure to get your iron reserves (aka ferritin) checked every so often, since many polyphenols can bind iron. Same is true for tannins such as those in coffee — another major source of chlorogenic acids.

  9. Rick Says:

    P.S. I believe the Solgar Blueberry Leaf is discontinued.

    Fyi, the before-meal regimen that worked so well for me was 2 standardized Puritan Blueberry Leaf Softgels (60mg, containing 10mg chlorogenic acid); 1 500mg Mulberry Leaf Gelcap (very hard to find but available and very inexpensive at Swanson); 1 500mg Quercetin Gelcap (apparently blocks some glucose traspoters); and 1 Chromium Polynicotinate Gelcap (try to stick to a brand that uses ChromeMate, as it has a good purity record).

    I should mention that by itself, non-standardized Mulberry Leaf didn’t do much for me, but in combo with the Blueberry Lead it clearly enhanced the effect (Swanson’s very potent and pricier *standardized* Mulberry Leaf is a very different story and has a big effect on its own…I sometimes used it as an alternate to the entire combo — but that’s getting pretty far off topic.)

    Yes, that’s a lot to down before a meal, but it sure helped my glucose control a lot and very consistently. I would often try to keep use to two meals a day, especially the Quercetin.

  10. JP Says:

    Thank you for sharing your findings with us, Rick. A great account from a decidedly balanced vantage point. Much appreciated.

    Be well!

    JP

  11. Lee Says:

    Hi there JP ,

    Can I know if those teas like Alvita blueberry leaf tea works or not?

  12. JP Says:

    Hi, Lee.

    IMO, blueberry tea leaf will likely produce some health benefits. However, it’s hard to say how it compares to standardized (blueberry leaf) extracts. Tea is a more natural source of this medicinal food. It’s not altered in any way. Having said that, because it’s left in it’s natural state, it likely has a lower and variable content of the “active” ingredients found in blueberry leaf extracts i.e. chlorogenic acid, myricetin, etc. In other words, the standardized extracts are more like natural medications. The tea is more like a medicinal food.

    Be well!

    JP

  13. JP Says:

    Update 04/21/15:

    http://www.jdmdonline.com/content/14/1/22

    J Diabetes Metab Disord. 2015 Apr 9;14:22.

    Improvement of glucose and lipid profile status with Aloe vera in pre-diabetic subjects: a randomized controlled-trial.

    BACKGROUND: Pre-diabetes is a disturbing trend in the population, who are at risk of developing type-two diabetes. The aim of this study was to determine the effects use of Aloe vera in different doses on glucose and lipid profile in pre-diabetic subjects.

    METHODS: This study was a double blind randomized controlled trial (72 subjects) with pre-diabetes symptoms in 3 groups consumed capsules twice a day: Aloe vera 300 mg (AL300), 500 mg (AL500) and placebo (PL). Fasting blood glucose (FBS), HbA1C and lipid profile were evaluated in baseline, 4 or 8 weeks. On-way ANOVA, Friedman, Wilcoxon, Kruskal-Wallis , Mann-Whitney and Chi-square tests were used for within or between groups statistical analysis.

    RESULTS: FBS level in group AL300, showed significantly decreased in fourth week after the intervention, compared to PL in the same time (p = 0.001). Also, HbA1C level in this group at the eighth week after the intervention (p = 0.042), had a significant decrease. The levels of Total cholesterol and LDL-C, only in the group AL500 (p < 0.001 and p = 0.01), was significantly reduced, along with HDL-C level improvement just after eight weeks (p = 0.004). Triglyceride level showed a significant decrease (p < 0.045) just after four weeks use of AL500. CONCLUSIONS: The Use of Aloe vera extract in pre-diabetic patients, could revert impaired blood glucose within four weeks, but after eight weeks could alleviate their abnormal lipid profile. Be well! JP

  14. JP Says:

    Updated 06/04/16:

    http://www.ncbi.nlm.nih.gov/pubmed/27258314

    Antioxidants (Basel). 2016 Jun 1;5(2).

    Berry Leaves: An Alternative Source of Bioactive Natural Products of Nutritional and Medicinal Value.

    Berry fruits are recognized, worldwide, as “superfoods” due to the high content of bioactive natural products and the health benefits deriving from their consumption. Berry leaves are byproducts of berry cultivation; their traditional therapeutic use against several diseases, such as the common cold, inflammation, diabetes, and ocular dysfunction, has been almost forgotten nowadays. Nevertheless, the scientific interest regarding the leaf composition and beneficial properties grows, documenting that berry leaves may be considered an alternative source of bioactives. The main bioactive compounds in berry leaves are similar as in berry fruits, i.e., phenolic acids and esters, flavonols, anthocyanins, and procyanidins. The leaves are one of the richest sources of chlorogenic acid. In various studies, these secondary metabolites have demonstrated antioxidant, anti-inflammatory, cardioprotective, and neuroprotective properties. This review focuses on the phytochemical composition of the leaves of the commonest berry species, i.e., blackcurrant, blackberry, raspberry, bilberry, blueberry, cranberry, and lingonberry leaves, and presents their traditional medicinal uses and their biological activities in vitro and in vivo.

    Be well!

    JP

  15. JP Says:

    Updated 06/04/16:

    http://www.sciencedirect.com/science/article/pii/S0014483516300112

    Exp Eye Res. 2016 Apr;145:258-68.

    Quercetin glycosides and chlorogenic acid in highbush blueberry leaf decoction prevent cataractogenesis in vivo and in vitro: Investigation of the effect on calpains, antioxidant and metal chelating properties.

    The present study investigates whether highbush blueberry leaf polyphenols prevent cataractogenesis and the underlying mechanisms. Chlorogenic acid, quercetin, rutin, isoquercetin and hyperoside were quantified in Vaccinium corymbosum leaf decoction (BBL) using HPLC-DAD. Wistar rats were injected subcutaneously with 20 μmol selenite (Na2SeO3)/kg body weight on postnatal (PN) day 10 (Se, n = 8-10/group) only or also intraperitoneally with 100 mg dry BBL/kg body weight on PN days 11 and 12 (SeBBL group, n = 10). Control group received only normal saline (C). Cataract evaluation revealed that BBL significantly prevented lens opacification. It, also, protected lens from selenite oxidative attack and prevented calpain activation, as well as protein loss and aggregation. In vitro studies showed that quercetin attenuated porcine lens turbidity caused by [Formula: see text] or Ca(2+) and interacted efficiently with those ions according to UV-Vis titration experiments. Finally, rutin, isoquercetin and hyperoside moderately inhibited pure human μ-calpain. Conclusively, blueberry leaf extract, a rich source of bioactive polyphenols, prevents cataractogenesis by their strong antioxidant, chelating properties and through direct/indirect inhibition of lens calpains.

    Be well!

    JP

  16. JP Says:

    Updated 09/26/16:

    http://www.mdpi.com/2076-3921/5/2/17/htm

    Antioxidants (Basel). 2016 Jun 1;5(2).

    Berry Leaves: An Alternative Source of Bioactive Natural Products of Nutritional and Medicinal Value.

    Berry fruits are recognized, worldwide, as “superfoods” due to the high content of bioactive natural products and the health benefits deriving from their consumption. Berry leaves are byproducts of berry cultivation; their traditional therapeutic use against several diseases, such as the common cold, inflammation, diabetes, and ocular dysfunction, has been almost forgotten nowadays. Nevertheless, the scientific interest regarding the leaf composition and beneficial properties grows, documenting that berry leaves may be considered an alternative source of bioactives. The main bioactive compounds in berry leaves are similar as in berry fruits, i.e., phenolic acids and esters, flavonols, anthocyanins, and procyanidins. The leaves are one of the richest sources of chlorogenic acid. In various studies, these secondary metabolites have demonstrated antioxidant, anti-inflammatory, cardioprotective, and neuroprotective properties. This review focuses on the phytochemical composition of the leaves of the commonest berry species, i.e., blackcurrant, blackberry, raspberry, bilberry, blueberry, cranberry, and lingonberry leaves, and presents their traditional medicinal uses and their biological activities in vitro and in vivo.

    Be well!

    JP

Leave a Comment