Monday, January 27, 2014

Will Drinking Tea Solve Our Sugary Problems? Commercial Tea Preparations Contain Effective "Carb Blocker"

Tea: An anti-oxidant carb-blocker with class - The Britons do it right - the always have a cup of tea with their scones.
As a (hopefully) regular SuppVersity reader you will know that I don't buy into either the fructose or the sucrose theory of everything (diabetes, cancer, obesity, stupidity, etc.). This does not mean that I wouldn't understand that the average Westerner would largely benefit from a reduction in carbohydrate intake. A reduction that - and this is what a recent paper in the peer-reviewed journal Advances in Preventive Medicine can tell us could be achieved by something as simple as drinking more tea (Oboh. 2014).

Commercial teas turn out to be carb-blockers

In said paper Ganiyu Oboh and his colleagues from the Federal University of Technology and the Obafemi Awolowo University in Nigeria report that:
"The antidiabetic property of the teas could be attributed to their inhibitory effect on carbohydrate hydrolyzing enzymes implicated in diabetes and their antioxidant activities." (Oboh. 2014)
And despite the fact that this still is a hypothesis, the results of their  would provide us with another mechanism to explain the previously reported beneficial effects of regular consumption of tea (in general!) on type II diabetes risk.

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The fact that the researches didn't just use any extracts, but bought their samples, 4 different commercial samples of bagged tea leaves of three brands, i.e.
  • one green tea (GT), 
  • two black teas (BT1 and BT2), and
  • one formulated herbal preparation for diabetes (ADT) 
right from regular supermarkets in Akure metropolis, makes the results only more relevant. Ok, one of the teas certainly sticks out, the "anti-diabetes tea" (ADT) was composed of white tea (63.4%), Radix puerariae (8%), Radix ophiopogonis(6.2%), hawthorn berry (10%), Chinese yam (6.2%), and fragrant Solomon seal rhizome (6.2%) and certainly sounds as if someone had opened the caps of one of the myriad currently available "insulin sensitizers" or "fat burners" into one of those tiny teabags - unfair? We'll see.

More than just antioxidants!?

If you take a closer look at the ADT formula (no, that's not "ATD" the anti-aromatase inhibitor with anti-libido and anti-androgen side effects | learn more), even a "non-noob" who has long lost all faith in the grandiose promises of the supplement industry would say: "Hey that could work!" Why? Well...
  • Figure 1: 2,2-Azizobis (3-ethylbenzo- thiazoline∼6-sulfonate; ABTS) scaven- ging ability and ferric reducing property of the teas (Oboh. 2014)
    White tea has already been shown to reduce most of the diabetes associated abnormalities in a steptozotocin-induced diabetes model of rats (Islam. 2011).
  • Radix puerariae which is also known as "Kudzu root" contains puearin, which is a scientifically proven antioxidant that helps with diabetes and cariovascular disease (Wong. 2011).
  • Radix ophiopogonis is another anti-oxidant TCM staple with proven anti-diabetic effects (Chan. 2008)
  • Hawthorn, Chinese Yam and Solomon seal rhizome are likewise potent antioxidants, although direct anti-diabetic effects are not well-established they may help sooth the symptoms / consequences of high blood sugar (specifically heart disease; Walker. 2006; Chang. 2004; Khan. 2010)
And still, the antioxidant properties, of this mixture fall short of those of green tea and the black tea preparation #1 (see Figure 1).

In the end, antioxidants were yet not what the researchers were really interested to begin with. What Oboh et al. wanted to know was whether or not there may be another way by the means of which teas exert their epidemiologically established effects.
Figure 2: Inhibition of 𝛼-amylase (left) and 𝛼-glucosidase (right) by aequeous extracts from some commercially available teas (Oboh. 2014). GT: Green tea; BT: Black tea; ADT: antidiabetes tea.
Their ability to inhibit the action of the carbohydrate digesting enzymes α-amylase and α-glucosidase, the enzymes which catalyse the hydrolysis of starch into disaccharides and trisaccharides and break down the latter into glucose, was of much greater interest to the scientists.
Maybe the effects would be even more pronounced if it wasn't for the "Potentially Hazardous Amounts of Lead, Aluminum, Arsenic & Co in Commercial Tea Preparations" | more
So is "carb-blocking" really how tea works its anti-diabetic magic? It's difficult to tell to which degree their ability to inhibit carbohydrate digestion actually contributes to the anti-diabetic effects of tea. With a 40% and 80-90% inhibition at concentrations of only 50mg/ml, it is yet at least likely that the inhibition of two major steps in the digestion of starches (α-amylase) and di- and trisaccharides (α-glucosidase) contributes to the -16% reduction in diabetes risk of people who consume "aqueous extracts of tea" (=a regular tea infusion) on a regular basis Huxley et al. report in their pertinent 2009 meta-analysis in the Archives of Internal Medicine (Huxley. 2009).

Reference:
  • Chan, Judy Yuet‐Wa, et al. "Protective effects of an herbal formulation of Radix Astragali, Radix Codonopsis and Cortex Lycii on streptozotocin‐induced apoptosis in pancreatic β‐cells: an implication for its treatment of diabetes mellitus." Phytotherapy Research 22.2 (2008): 190-196.
  • Chang, Sue-Joan, et al. "Chinese yam (Dioscorea alata cv. Tainung No. 2) feeding exhibited antioxidative effects in hyperhomocysteinemia rats." Journal of agricultural and food chemistry 52.6 (2004): 1720-1725.
  • Oboh, Ganiyu, et al. "Interaction of Some Commercial Teas with Some Carbohydrate Metabolizing Enzymes Linked with Type-2 Diabetes: A Dietary Intervention in the Prevention of Type-2 Diabetes." Advances in Preventive Medicine 2014 (2014).
  • Huxley, Rachel, et al. "Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2 diabetes mellitus: a systematic review with meta-analysis." Archives of Internal Medicine 169.22 (2009): 2053.
  • Islam, Md. "Effects of the aqueous extract of white tea (Camellia sinensis) in a streptozotocin-induced diabetes model of rats." Phytomedicine 19.1 (2011): 25-31.
  • Khan, Haroon, et al. "The antinociceptive activity of Polygonatum verticillatum rhizomes in pain models." Journal of ethnopharmacology 127.2 (2010): 521-527.
  • Walker, Ann F., et al. "Hypotensive effects of hawthorn for patients with diabetes taking prescription drugs: a randomised controlled trial." The British Journal of General Practice 56.527 (2006): 437.