Wednesday, April 25, 2012

For Healthy Green Tea, Brew Your Own

Never shy about jumping on a health bandwagon, industrial beverage manufacturers have been cashing in on the benefits of green tea, which they have formulated in a dazzling array of delectable flavors. (Ginseng and honey anyone? Nectarine white tea? And for the cancer-conscious, green tea with pomegranate extract, perhaps?)

Alas, these beverages have very little nutritional value, and in terms of cancer prevention they may actually be counter-productive. For one, this is because they are usually sweetened with refined sugars (about 2 tablespoons of sugar per standard 8oz/240ml glass). As is increasingly understood, sugar and the hormones its consumption triggers—insulin and IGF-1—promote the growth and spread of cancer cells, as well as fueling weight-gain, another cancer risk factor.

Moreover, bottled or canned tea beverages have levels of polyphenols and antioxidant activity 10 to 100 times lower than conventionally brewed tea, experts say. "Many of the currently available cold bottled teas sold in the U.S. are more like diluted sugar water than something that will help protect your health," according to Professor Ron Dashwood of Oregon University. "The antioxidant or polyphenol activity found in some of them may be due in large part to the fruit additives used as flavorings, and have little to do with the tea polyphenols."

Lastly, bisphenol-A and other estrogen-mimicking compounds found in many plastic bottles and can linings may pose a further risk (as I have described here and here).

If it’s a fun, refreshing, sweet-tasting beverage you’re after, bottled tea drinks may be all right occasionally. But if you are drinking tea to lower your risk of cancer, heart disease, osteoporosis and a whole list of other degenerative conditions, brew your own.

Black, oolong, green and white tea come from the same Camellia sinensis plant; white tea is the least processed and provides the largest quantity of antioxidant and anti-cancer compounds, notably a flavonoid by the tongue-twisting name of epigallocatechin-3-gallate (EGCG).

Tea—especially the more widely studied green tea—is thought to have many anti-cancer effects. For starters, it may prevent the formation of cancer cells: Observational studies associate regular intake of green tea with lower risk for bladder, colon, stomach, pancreatic and esophageal cancers.

The phytochemicals in green tea have also been shown to increase the production and activity of detoxification enxymes in humans and may enhance our ability to detoxify carcinogens. Where there are cancerous cells present, green tea may slow their growth and spread: it is thought to inhibit angiogenesis (the growth of new blood vessels to nourish a tumor) and trigger apoptosis (spontaneous self-destruction of cancer cells).

If three or four daily cups of green tea may have cancer-protective properties, this doesn't mean you should guzzle a gallon a day for even greater protection; "more" is not always "better." While the science is still unclear, excessive amounts of plant compounds like EGCG -- particularly when taken in the form of highly concentrated supplements -- may not necessarily be helpful, especially for people undergoing radiation therapy, and possibly chemotherapy too. This is because green tea's antioxidants may protect not only normal tissues, but cancerous cells too, from the intentionally oxidative effects of the treatment.

It used to be thought that green tea has to be drunk immediately after brewing to obtain maximum EGCG levels. Adding lemon or lime juice to green tea, however, helps to stabilize flavonoid levels, which means you can drink it hours later and still obtain good EGCG intake.

My clients often tell me they don’t drink green tea because they dislike its bitter taste. The good news is: you don’t have to drink it plain. A little added lemon juice and honey not only makes green tea taste fresher and less bitter; researchers have also found that this enhances the body’s uptake of EGCG’s four-fold as compared with green tea drunk plain.

Other ways of reducing bitterness is not to brew the tea with boiling water (keep it at 70°C to 80°C (155°F - 180°F)) and not to let it steep for more than three minutes.

As summer approaches, here’s another great way to make the most of tea: cold-brew it! Not only is this type of tea milder, lower in caffeine and more energy-efficient than hot-brewed tea; it may also have greater antioxidant benefits. In an Italian study, tea steeped for two hours in cold water was substantially better at protecting cholesterol from oxidation than tea that had been brewed with hot water.

To vary the flavors, add some chopped ginger, a sprig of mint, or some unsweetened orange juice or cherry syrup to hot or cold tea. Spice lovers may enjoy green tea brewed with Indian “chai” spices and (cinnamon, ginger, allspice, cardamom, pepper) and a smidgen of honey. (Zest for Life has three recipes for hot and cold green tea preparations, as well as chicken soup and chilled fruit soup made with green tea.)

Glass drinking straws, really??

Glass drinking straws have become all the rage as health-conscious consumers seek to reduce their exposure to potentially cancer-causing plastic compounds in their food.

From smoothie-slurping bloggers worrying that plastic straws will “leach trace amounts of toxic chemicals into food and into your body” to environmentally conscious sippers bent on “saving … sea creatures from ingesting little teeny tiny pieces of plastic,” it seems the glass straw will save our health and that of our planet.

Drawing my attention to this new phenomenon, a reader recently suggested that instead of drinking coffee through the plastic lids that coffee houses pop on paper cups, we should sip it through glass straws poked through said plastic lids. But does this really solve the problem of BPA and plastic food containers? Unfortunately, no.

For purely esthetic considerations, I’d be the first to favor glass straws: they’re beautiful, natural, reusable and therefore environment-friendly. Manufacturers even claim that they’re shatter-proof, though I wouldn’t want to test this promise on my kids (especially as they retail at a hefty $7 to $10 apiece!).

But as long as we continue drinking coffee, tea and other hot beverages from plastic-lined paper cups, glass straws won’t make much difference. You see, it’s the paper cup that’s the main culprit, not the plastic straw.

Paper cups intended for hot drinks are laminated with a liner made of polyethylene that helps keep beverages warm and prevents the paper from getting soggy and leaking. However, polyethylene has estrogenic properties much like BPA, and these so-called “xenoestrogens” (man-made chemicals that mimic the natural human hormones) are linked to a growing number of health problems, such as breast, ovarian, testicular, and prostate cancers, early puberty in girls, reduced sperm counts, altered functions of reproductive organs, obesity and behavioral problems.

A US government funded study published last year in the science journal Environmental Health Perspectives found that the vast majority of commercially available food-grade plastics such as polyethylene, polypropylene, polystyrene, and polyethylene terephthalate, leach estrogen-like compounds into the foods and drinks they contain—even those that are marked as being “BPA-free.”

Making matters worse for the paper cup, it’s not environmentally friendly. Its plastic lining prevents the cup from being recycled, and so every paper cup that is manufactured and lined with plastic ends up in a landfill. There, the paper will decompose, releasing methane, a greenhouse gas with 23 times the heat-trapping power of carbon dioxide, according to Sustainability is Sexy, a Seattle-based organization that seeks to “reduce the bitter environmental, social and financial impact of disposable coffee cups”.

So here’s my bold recommendation: just do away with paper cups and glass straws altogether. To enjoy a hot drink, all you need is an old-fashioned cup made from ceramic, china or glass and a few minutes to prepare and enjoy your drink.

When you look at Mediterranean food traditions (which I celebrate in Zest for Life), people in France, Italy and Spain drink coffee mostly as a treat and a gentle stimulant (one in the morning to get going, another after lunch to help stimulate digestion, and occasionally a third as an afternoon pick-me-up), not as a source of hydration.

They drink small quantities of strong coffee out of tiny espresso cups like the ones pictured above. Because these small coffees don't take long to get through, most people sit at a table or stand a bar and enjoy their beverage without doing anything else (e.g. eating, driving, running for a train, shopping, etc.). For this reason, plastic lids aren't necessary.

If you must carry coffee with you, I suggest you prepare it at home and fill it into a stainless-steel thermos where it will keep warm for hours and not spill if you have to run or drive. I do this when I take long road trips and it works beautifully: I get to drink my favorite brand of coffee from a non-reactive container at a fraction of the cost of a cup of coffee from a coffee shop and without needing to use cardboard, plastic or glass straws. It's better for the environment too, as this generates no garbage except for a few (biodegradable) coffee grinds.

Friday, April 6, 2012

Another Reminder To Ditch Cans And Eat Fresh Food

The FDA's decision to let food manufacturers continue using bisphenol-A (BPA) in food packaging is the best news I've heard in a long time.

This statement may surprise regular readers of this blog, who will remember me fulminating against BPA here, here and here.

The thing is: the ruling highlights that food manufacturers and regulators can't always be expected to make the best decisions for our health. And this realization -- somewhat perversely -- gladdens my heart because it should prompt consumers to think even harder about their food choices. (Sorry folks.)

In response to a 2008 petition by the Natural Resources Defense Council's to ban BPA on the grounds that it causes harm, the Food and Drug Administration last Friday rejected the petition, claiming insufficient evidence for adverse health effects in humans. The agency did say it would continue studying BPA for more conclusive evidence, but critics argue there’s already ample evidence indicating that the chemical may increase the risk of cancer, heart disease, fertility problems, diabetes and obesity.

BPA contains so-called xenoestrogens (i.e. estrogen-like chemicals that mimic the natural human hormones) that are being linked to a growing number of health problems, such as early pubertyin girls, reduced sperm counts, altered functions of reproductive organs, obesity, and increased rates of breast, ovarian, testicular, and prostate cancers. They are thought to be particularly harmful to fetuses, infants and children, but may affect adults too. Particularly worryingly to cancer patients, BPA can block the effects of certain chemotherapy drugs, even at low concentrations.

So what’s a concerned eater to do whilst the health authorities and food industry continue to drag their feet? (Which they may continue doing for some time to come, given that the leading players in the $8bn BPA market and the $60bn canning industry aren’t likely to go quietly.)

We can vote with our wallets.

For one, we can choose BPA-free packaged foods (this post lists products available in PBA-free cans). In response to consumer demand, some food producers, such as Eden Organic, began removing BPA from its cans years ago; others, such as Campbell’s Soup, joined them more recently. NestlĂ© and Heinz and ConAgra have indicated they will phase out the chemical in coming years.

To keep up the pressure on food manufacturers, packagers and retailers (who, following the FDA’s ruling, may feel tempted to continue using BPA), we should keep writing letters asking for dangerous plastics to be removed from our food. Feel free to use the form letter I suggest here.
Even more radically, we can make more home-cooked meals from fresh, unprocessed food and cut down the amount of packaged comestibles we eat in the first place.

As a study published last year showed, families who gave up canned foods and food packaged in plastic containers saw their levels of BPA fall by 66% in the space of three days. As I show regularly in my cooking videos, it doesn’t take much time or effort to prepare meals from fresh, unpackaged ingredients.

Meanwhile, here are some other simple ways of avoiding BPA and other plastics:
  • Buy fresh, unpackaged food from vegetable stores, CSA schemes, farmers' markets etc. and using it up quickly
  • Use a freezer for long-term food storage, reducing the need for cans (frozen vegetables and fruits are more flavorful and nutritious than canned ones anyway)
  • Drink fresh water from glass or stainless steel containers, avoid sodas, beer and other beverages in cans.
  • Replace plastic storage containers with glass or stainless steel containers
  • Can your own food: I preserve vegetables and fruits in in glass jars (much tastier than store-bought canned equivalents) and was surprised to see how easy this is. When canning food, be careful to follow reliable instructions to avoid poisoning your family with dangerous bacteria. Also, don’t buy cans whose lids are lined with BPA-containing plastics; I recommend brands with glass lids and rubber seals (e.g. Weck).
  • Babies should drink from glass bottles; toddlers can use stainless steel sippy cups. Avoid plastic bottles or cups and formula packaged in plastic-lined containers.
  • Use ceramic, glass or metal bowls to prepare or serve food. This is especially important if you use a microwave oven.
  • Use wooden or stainless steel cooking tools (spoons, spatulas, strainers etc.) instead of plastics.
  • At the dining table, use china or earthenware plates, and pitchers and glasses made of glass, not plastic.
  • Instead of a plastic water kettle, use an old-fashioned enamel or stainless steel stove-top kettle.
  • Instead of using automatic espresso machines, opt for a stainless steel stovetop espresso maker. If you make drip-filtered coffee, use paper filters in a ceramic, glass or stainless steel filter holder, rather than plastic equivalents.