Drink Tea! Lose Weight?

best tea for weight loss!
weight-loss teas!!
drink tea to lose weight!!!


shangri-lade-montage-webWhat’s not to love about that?

Drink what I love and lose weight at the same time?!

Except for the fact that I drink tea all day long and have not experienced any notable weight loss. And the fact that I am always skeptical of claims written with exclamation marks!

But every so often these claims re-emerge in news reports—enough to keep people talking.

And it turns out that there is some science behind the claims—enough to keep scientists pursuing this line of research.


First, the secret to weight gain (or, what happens when we eat lots and lots of junk food)

Not so hard to figure out the cause and effect of food and physique! What happens physiologically is that:

  • fat cells get bigger
  • we get more fat cells

527 brew_crop

Second, can we counteract that??

Back in 2009, J. Söhle and colleagues looked at human precursor fat cells (preadipocytes) and white tea extract. Did tea affect whether the precursors matured into full-blown fat cells (or adipocytes, specialized cells that store fat)?

Short answer? Yes, actually.

And were their results tea dependent?

Well, they used white tea because it undergoes the least processing (oxidation) of all the teas, and only the new growth (buds and first leaves) of the plant are used. This means that white tea contains more polyphenols (including epigallocatechin [EGCG] and epicatechin) and more methylxanthines (caffeine and theobromine) than do green or black teas.

So about those results—

Söhle’s team (2009) found that the human cells exposed to white tea extract had lower triglyceride levels; the acting agent may be the polyphenol EGCG.

Lower triglyceride levels mean that fat is being broken down (lipolysis), with triglycerides being converted into fatty acids and glycerol.

Further, white tea extract appeared to discourage precursor fat cells from turning into full-fledged fat cells—at least in human subcutaneous cells. As Söhle et al. (2009) state,

This plant [white tea] extract is, therefore, an ideal natural source to modulate the adipocyte life cycle at different stages and to induce anti-obesity effects.

The caveat?

Exposing cells to white tea extract under laboratory and controlled circumstances is nowhere the same as a person drinking a cup of white tea.

However,

We do know that tea—Camellia senensis leaves—provides many health benefits, and results of this study are definitely encouraging. So I am putting the kettle on right now!


Source: Söhle, J. et al. “White tea extract induces lipolytic activity and inhibits adipogenesis in human subcutaneous (pre)-adipocytes,” Nutrition & Metabolism 6:20. 2009.

Is Climate Change Real? Ask a Tea Grower!

science-cookies2_web
Science cookies by TeaHaus, Ann Arbor

Many of us spent Saturday—Earth Day—thinking about our planet and our role  in caring for it.

So what about tea production? Any problems there? Should we be hoarding our favorite tea?!

From Damage in Darjeeling

During winter in Darjeeling, no tea is harvested, and the bushes are pruned to encourage new growth. Then in spring, warmer weather brings a burst of new leaves—the first flush so highly anticipated and valued.

Tea connoisseurs, of course, are thinking about first-flush Darjeeling’s incredible flavor.

A whole lot of other people, however, are more concerned about the economic ramifications of this first-flush harvest—because it accounts for around one-third of the year’s total tea value!

So just as farmers do everywhere, tea growers watch the weather. As quoted in the Economic Times (Sarkar 2017), scientist S. E. Kabir said:

Weather during this period plays [a] vital role behind quality and quantity of first flush. Tea is a chill loving plant and demands adequate humidity in air or soil. Less than normal humidity or above normal temperature can seriously retard metabolic function of bushes hampering its health rejuvenation.

This year, rainfall and humidity were first significantly lower, and temperatures significantly higher, than normal—followed by constant rain and no sunshine, which is equally detrimental to tea production (Ghosal 2017).

To Adversity in Assam

Meanwhile, over in Assam—one of the world’s largest tea-producing regions—heavy rains coupled with the failure of bushes to produce leaves are “likely to bring down total tea production by 30% during March, feel planters” (Ghosal 2017).

Sure, yearly fluctuations in weather are expected and normal. But are current weather problems normal?

Back in 2015 I wrote Assam Tea At Risk? Climate Change Threatens. And then, in 2016, Assam was beset:

–first by drought (bringing pests and plant loss)
–followed by heavy rains (plants didn’t get nutrients because there wasn’t enough sunlight, plus the sodden ground caused roots to rot)
–that brought widespread flooding (countless people were homeless with entire villages underwater)

Assam’s longer-term problems include:

  • Rainfall and monsoons have become less predictable.
  • Vacillations in rainfall are devastating to tea. A NASA program was designed to measure soil moisture (to allow smart irrigation)—but the equipment aboard the satellite malfunctioned (read more).
  • Soil fertility has deteriorated.
  • Lowland Assam tea is on the boundary of tea-growing regions, and so is the first affected by temperature increases (Kahn 2015).
  • Tea is produced by hand, so over two million workers in Assam are affected when tea quality and quantity decline.

So Is Tea at Risk?

The writing may well be in the [lack of] tea leaves.


Sources:
–Doshi, V. “Flooding in India affects 1.6m people and submerges national park,” The Guardian, July 27, 2016.
–Ghosal, S. “Rains wash off tea’s premium edge,” Economic Times, April 3, 2017.
–Kahn, B. “Global warming changes the future for tea leaves,” Scientific American, June 4, 2015.
–Sarkar, D
. “Darjeeling’s high value first flush tea under trouble,” Economic Times, February 7, 2017.

Should You Microwave Your Tea? Part 2: Flavor

According to researcher Dr. Vuong (Hoh 2017), brewing tea in a microwave oven imparts greater health benefits and results in tastier tea.

So, About This Claim

While I cannot test the health factor (see my previous post), I can test the flavor! Admittedly my little experiment wouldn’t meet any laboratory standards, but anyway.

I brewed teabags (standard teabags, purchased from a grocery store) and loose leaf Chinese green teas (again, standard tea)—both in the conventional manner and with Dr. Vuong’s method.

Experiment 1: Brewing a Teabag

I used 8 ounces of hot water, steeping a teabag of Chinese green tea for 2 minutes.

I put a second teabag into hot water and immediately microwaved it for 30 seconds at half power, and then let it sit for a minute before removing the teabag, per Dr. Vuong, who advocates this method.

Neither he nor the teabag company suggested what temperature “hot” should be, so already this experiment is not at all controlled. Nor does Vuong provide what wattage the “half power” should be.

Experiment 2: Brewing Loose Leaf Tea

I measured a teaspoon of loose Chinese green tea and brewed it in 8 ounces of hot water for 2 minutes.

I put another teaspoon of loose tea into 8 ounces of hot water and immediately microwaved it for 30 seconds at half power. After letting it sit for an additional minute, I filtered out the leaves.

So Does the Microwave Make a Difference?

I had my husband and daughter do a blind taste test.

Teabag Results
Me: 
preferred microwave version because it was stronger
Husband: thought the microwaved version was stronger but he preferred the conventionally brewed one
Daughter: thought the microwaved version was stronger but the conventionally brewed one was sweeter

Loose Leaf Tea Results
Me: microwaved version was awful so totally preferred the conventionally brewed version
Husband: preferred conventionally brewed one
Daughter: thought the conventionally brewed tea was stronger but the microwaved one was sweeter

The Upshot

With Teabags
It seems—based on this extremely limited trial—that if you are using a teabag and you like stronger tea, you may want to give the microwave a try.

These results intuitively make sense because in this photo of the teabag contents after brewing, you can see that the tea leaves have been chopped into tiny bits.

When they are brewed, there is a lot of surface area and the flavor is quickly extracted.

The microwave apparently maximizes that process, without contributing bitterness to the brew.

With Loose Leaf Tea
If, however, you have loose leaf tea, I personally would follow the recommended conventional brewing method.

For the loose leaf tea, the leaves are in large pieces or nearly whole, as seen in the photo here, taken after brewing.

Compared to small bits of leaves, whole leaves retain more of their flavor and health benefits, and they also release them more slowly—which is why many green, white, and oolong teas can, and often should, be brewed more than once.

The microwave was not sufficient, at least in my little study, to extract the flavor that I expect from these leaves.


Source: Hoh, A. “Microwaving tea the best way to brew and extract health benefits,” ABC News, April 10, 2017

Should You Microwave Your Tea? Part 1: Health Benefits

microwaving teaA perhaps disconcerting study has been recently publicized. It promotes—of all things—microwaving your tea so that you obtain more of its health benefits.

Moreover, scientist Dr. Quan Vuong asserts that this technique yields a better-tasting cup.

Anathema! Nuke my tea? No way!

But why was Dr. Vuong microwaving his tea anyway?

As reported by ABC News–Australia on April 10, Vuong focuses on how to best extract components from foods and beverages—so that these compounds can be added to other food products or used in supplements.

china lung ching 2And tea is simply loaded with highly beneficial stuff:

Caffeine

Yes, caffeine has plenty of real health benefits (click here to see why we might want to embrace it). Extracted caffeine is also added to other beverages and to medicines.

L-Theanine

This highly desirable amino acid, found nearly exclusively in tea:

  • Gives tea its umami flavor. (Shade-grown tea has more theanine than tea grown in sunlight, driving up both tea quality and price.)
  • Increases alpha wave activity in our brains. These are the brain waves that relax us (think meditation or mindfulness).
  • Works synergistically with caffeine to improve brain function and attention.
  • May prevent some cancers and heart disease, boosts our immune system, and helps us lose weight (Vuong et al. 2011).

Polyphenols/Catechins

And of course tea is loaded with phenols, which are incredibly good for us in myriad ways (may prevent cancer, heart disease, diabetes, dementia, etc.).

Vuong and his colleagues (2010:3426) speculate, however, that just drinking tea “may not provide a sufficient level of catechins to achieve these health benefits”—hence his efforts on extracting and concentrating phenols so they can be added to other foods.

(While not negating the benefits of consuming more phenols, I would say that there are other research studies that indicate that drinking tea does have measurable effects.)

Which brings us to:

Extracting these elements

When we make a cup of tea at home, we use hot water to extract flavor, caffeine, theanine, and polyphenols from the tea leaves.

For extraction on a large scale and for commercial applications, however, methods must be as efficient, reproducible, safe (for employees, consumers, and environment), and cost effective as possible.

Therefore Vuong and his colleagues (2010, 2011) experimented with multiple ways (including with a microwave) to extract theanine and polyphenols, using varying solvents, temperature, time, and so on.

They found that the process was most efficient with ground dried tea. They also learned that they could extract the most theanine at 176°F for 30 minutes and a ratio of about 6 ounces of water to 0.035 ounces of tea (20 ml water per gram tea) (Vuong et al. 2011:2474).

Needless to say, extracting bulk theanine to add to other products is a whole different thing than extracting it in your teapot where the goal is largely to make a great cup of tea!

Which brings us to the microwave

For immediate home use, Vuong (Hoh 2017) asserts that you can obtain 80% of tea’s caffeine, theanine, and polyphenols—and the best flavor—by making tea this way:

  1. Put hot water in the cup with your teabag.
  2. Heat in the microwave for 30 seconds on half power.
  3. Let it sit for a minute.

Does it work? Well-l-l-l-l . . . .

Well, as far as health benefits go, that depends on whether you believe the science is correct, and as consumers, this is difficult to verify. For one, we must watch for additional research that supports Vuong’s claims.

I would say, however, that the “half power” thing is extremely non-scientific! Microwaves vary in wattage levels so half power of a small microwave will not be the same as that of a more powerful microwave. So how do we know if we are getting the 80% or not?

And as far as flavor goes, I’ll let you know in my next post!


Sources:
–Boros, K. et al. “Theanine and caffeine content of infusions prepared from commercial tea samples,” Pharmacognosy Magazine 12(45):75–79. January–March 2016.
–Hoh, A. “Microwaving tea the best way to brew and extract health benefits,” ABC News, April 10, 2017.
–Vuong, Q. V., et al. “Extraction and isolation of catechins from tea,” J. Sep. Sci. 33:3415–28. 2010.
–Vuong, Q. V., et al. “Optimum conditions for the water extraction of L-theanine from green tea,” J. Sep. Sci. 34:2468–74. 2011.

Milk in Tea?

939 brew in frameAdd milk?

Good heavens, no!

Adulterate an excellent cup of tea?!


Except, of course, a lot of people—perfectly fine people, friends of mine even—prefer to add milk to their tea.

And they are certainly entitled to do this.


But can I use science to support my strict No-Milk policy?

Well, like most things, answers are neither clear-cut nor simple.

That’s mostly because tea is pretty complicated. First, you have endless varieties of black and white and green and oolong tea, which means you aren’t necessarily comparing apples to apples.

Consider, for instance, those beneficial polyphenols—the reason that many of us drink tea. In green tea, these largely remain as flavanols or catechins (simple polyphenols).

To produce black tea, however, the leaves are more fully oxidized, which converts the simple polyphenols into more complex forms (theaflavin, which provides the bright taste, and thearubigin, which contributes complexity). While the green tea catechins and the black tea theaflavins seem to retain the same antioxidant potency (Leung et al. 2001), the complexity of the black tea components complicates research studies.

This means that the physiological effects of drinking black tea are more difficult to tease out. And milk is generally added to black tea, not green.

Some of the science of milk in tea:

One team of researchers studied how drinking hot caffeinated beverages affects our physiological response and mood—and how milk might change that response.

Among their results, they found that milk added to black tea or coffee had an impact only while the beverage was being consumed (Quinlan et al. 1997:171).

These effects included mitigating the increased heart rate and skin conductance that comes with drinking tea and coffee.

Milk didn’t seem to change the bioavailability of caffeine, and the presence of milk seemed similar to that of caffeine (Quinlan et al. 1997:172), improving mood for instance—though the authors note that this may because the people in this study said that they preferred milk in their tea or coffee!

(Yes, drinking something the way I like it would improve my mood and perhaps affect my heart rate!)

Quinlan and colleagues point out that because the addition of milk did not have lasting physiological effects, these effects may be “part of a sensory response, with milk perhaps reducing the sensory impact (e.g., bitterness) of the beverages in the mouth” (Quinlan et al. 1997:171).

My conclusion

Ummm, when you are doing a study on people who said at the outset “that they habitually consumed tea/coffee with milk” (Quinlan et al. 1997:165), some of these results seem a bit obvious.

But anyway, if you like milk in your tea, fine. Milk apparently doesn’t change the health benefits of drinking tea in any substantial way.

And it will make you happier if tea with milk is your cup of tea!


Sources:
–Leung, L. K., et al. “Theaflavins in black tea and catechins in green tea are equally effective antioxidants,” Journal of Nutrition 131(9):2248–51. 2001.
–Quinlan, P., J. Lane, and L. Aspinall. “Effects of hot tea, coffee and water ingestion on physiological responses and mood: The role of caffeine, water and beverage type,” Psychopharmacology 134:164–173. 1997.

Never Underestimate the Power of a Teapot

Teapot as Art

In the Which One Doesn’t Belong game, it’s pretty obvious which teapot here is not exactly a thing of beauty.

teapot montage

But they all can be used to make tea. And the very act of making tea—not to mention drinking tea—reduces stress.

Teapot as Calming Agent 

Researchers Cross and Michaels (2009) assert that

the ritual of making and consuming tea does make an important contribution to the overall effect of mediating stress. . . . [D]uring periods of stress tea’s reputation for inducing calm extends beyond the effects of its physical properties on our bodies and brains. The symbolic dimensions of tea . . . perform a complex socio-psychological function.

light fixtureTeapot as Tchotchke

But if we go beyond the intended use of teapots, we find all sorts of things.

Charming teapot birdhouses, teapot decorations, teapot light fixtures abound.

And Teapot as Scientific Instrument

Back in the 1960s—before we knew much about the role of CFCs in our environment—scientist James Lovelock developed a detector to measure atmospheric CFC.

To continue his research, Lovelock embarked on an expedition aboard the RRS Shackleton in 1972. However, he soon realized that the seawater pumped in by the ship for research purposes was too contaminated for his purposes.

So, Lovelock tried scooping up seawater using a bucket tied to a rope, but the ship was moving too fast and he was in danger of being pulled overboard. In his search for something more suitable, he ended up with tea ware!

As Walker (2007:141) relates:

an old aluminum teapot, now retired from active duty, would be just the thing. From then onward Lovelock cheerfully used this teapot to scoop up his daily water samples.

And these samples showed that CFCs were present everywhere, laying the groundwork for later work by S. Rowland and M. Molina that linked ozone depletion and CFCs.

Even a Lowly Teapot: Agent of Power

While the utilitarian teapot pictured above may not be considered beautiful by most, it can certainly:

  • delight
  • calm
  • help solve our world’s problems in unexpected ways
  • make a pot of tea, which itself delights, calms, and helps solves problems in unexpected ways

Sources:
Cross, M. and R. Michaels. “The Social Psychological Effects of Tea Consumption on Stress.” 2009.

Walker, G. An Ocean of Air, Orlando, FL: Harcourt. 2007. 

Juice, Fruit Tea, or Tea for Antioxidants?

fruit bowl_low resIt is pretty much common knowledge that antioxidants play a role in slowing the aging process (yes!) among many other health benefits. And fruit contains antioxidants.

Juicy News

Juice companies who supposedly have only our health in mind have jumped on this, citing studies that indicate that “our” juice has more antioxidants than “their” juice. And research has borne out the fact that juices indeed retain antioxidants from their original fruit.juice 1_low res

These antioxidants may help protect against Alzheimer’s disease (e.g., Mullen et al.’s 2007 paper cites purple grape, grapefruit, cranberry, and apple juices as being particularly valuable).

A more recent study evaluated juice that the researchers made from fresh fruit, and even after heat treatment (as in pasteurization), found that they “are good sources of antioxidants” (Benmeziane et al. 2016).

But there’s all that sugar, I say!—without the fiber that whole fruit provides.

But, of course, fruit juices, especially those without added sugar, could be a good option if people dislike or have trouble eating whole fruit.

FruiTea News

fruit tea 1_low resSo what about fruit teas? Well, their antioxidant levels have also been evaluated.

One study by Simon et al. (2016) compared 18 fruit teas . . . and discovered that the more ingredients (11 vs 6) that the fruit tea contained, the lower the levels of antioxidant capacity and polyphenol content. Which seems odd.

But when the researchers delved into their results, they found that the base of the fruit teas—hibiscus and apple—had higher levels of antioxidants than did the other ingredients (which were not listed in their article).

As the scientists point out, this could be because the antioxidants weren’t extracted from those other ingredients at brewing temperature, or they were destroyed at that temperature, or they were never there to begin with.

So while all of the fruit teas in this study did contain antioxidants, some contained more than others.

BUT, Plain Old Black Tea Wins the Antioxidant Contest!

black tea_low resYep, Simon and colleagues found that when compared to the fruit teas, the 2 samples of black tea (1 ingredient in each) had even more antioxidant capacity and a lot more polyphenols!

So because I am so totally on board for the anti-aging component of antioxidants—the more the better, right?!—I’m going to have another cup or two or three of tea, the Camellia sinensis one.

(And it certainly won’t hurt to have a cup of caffeine-free fruit tea later tonight. . . .)


Teas pictured here are available at TeaHaus. The fruit tea is caffeine-free Blood Orange, and the black tea is Darjeeling Rarity, a second flush black tea.


Sources:
Benmeziane, F., A. M. Abdourhamane, and A. Guedaoura. “Nutritional quality and bioactive compounds of some fruit juices,” Advances in Environmental Biology 10(4):242. 2016.

Mullen, W., S. C. Marks, and A. Crozier. “Evaluation of phenolic compounds in commercial fruit juices and fruit drinks,” J Agric Food Chem 55(8):3148–57. 2007.

Simon, I., D. Simedru, L. Dordai, E. Luca, V. Fuss, and A. Becze. “Evaluation of the antioxidant capacity and total polyphenols in different fruit teas,” Studia Universitatis Babes-Bolyai. Chemia 61(3):505. 2016.