Saturday, November 26, 2011

Secret 33: Make Time for Tea - Green Tea

Ignorance is not bliss. In Secret 33, Sally Beare sings the praises of green tea. She writes:
"High quality loose green tea leaves are the best, but you can also buy teabags". I agree with the first part of her statement, but would like to alert you to the danger in the second part. The five populations on which she bases her recommendations do not use teabags. And with good reason. Are you familiar with epichlorohydrin? Tea bags used to be made out of silk, but nowadays the most common material is paper. You know what happens when paper gets wet. If you've ever read a book in the bathtub, and your book falls in the water, the pages start to dissolve. Untreated paper tea bags do just that. Some sort of vehicle or medium is necessary to prevent the paper tea bag from dissolving while allowing the hot water to extract the tea flavor. The solution is to add epichlorohydrin. Epichlorohydrin is used by the food industry as a paper reinforcement in tea bags, coffee filters and sausage casings. It is a mildly toxic irritant. In water epichlorohydrin hydrolyzes to 3-monochloropropane-1,2-diol or 3-chloro-1,2-propanediol (3-MCPD). 3-MCPD is a carcinogen that also has undesirable affects on male fertility. Surely you would like to reap the benefits of green tea without running the risk of needlessly exposing yourself to carcinogens?

Camellia sinensis: the source of white, green oolong and black teas
To reduce your exposure to 3-MCPD, you have several options:
  • only drink tea in loose leaf form
  • call your favorite tea company and ask them about the source of their tea bags and the presence of epichlorohydrin. Some tea companies use biodegradable tea bags
  • if you already have a drawer full of tea bags, rather than throw out your stock, tear open the bag (it’s just paper) and use a tea infuser for the leaves when steeping them in hot water.

Use a tea infuser in lieu of tea bags
One last thought regarding 'tea bags': the tea leaves hidden in tea bags are often of lesser quality than those in loose leaf tea (if the customer cannot even see the tea leaves, why not throw in the dregs?). If you cannot visually inspect the tea, why purchase it? Who knows what is in it?  Would you be willing to swallow food blind-folded or food that is totally wrapped up?  

Now that we have addressed a risk of drinking green tea, let us examine the benefits:  

Green tea and the leaves from which it derives

  • green tea contains a powerful antioxidant called "epigallocatechin-3-gallate". Supposedly this is more powerful than resveratrol (from the skin of red graoes and other fruit) and Vitamin E.  It also has anti-carcinogenic properties (especially against cancers of the brain, bladder, genital). EGCG has been shown to reduce AIDS-related dementia plaques. It also enhances the body's defense system against systemic inflammation. 
  • it has antibiotic characteristics
  • it protects against dental caries
  • it is effective against bacteria that produces bad breath
  • it has less caffeine than other teas (one average serving size of green tea has 25 mg of caffeine. Compare this to 50-60 mg in black tea, and 150 mg in coffee).
  • it has beneficial cardiovascular effects. Supposedly the presence of milk reduces these benefits.
Adding lemon to green tea enhances the absorption of EGCG and other beneficial catechins. Note that the benefits of green tea are less prevalent in decaffeinated, flavored, bottled teas and instant tea mixes. The greatest benefits are found in the young tea leaf that grows right beneath the tea bud. Premium green tea consists of buds and the first leaves (rarely also the second leaves).

So how does green tea differ from black tea? Both teas are made of the leaves of Camellia sinensis but are processed (oxidized) for different lengths of time. Green tea is minimally oxidized. The oxidization is halted either by steam (Japanese tea) or by dry cooking in hot pans (Chinese tea). Black tea, on the other hand, is allowed to completely oxidize (thus reducing the concentration of catchins such as EGCG). The Japanese green tea 'gyukuro' is often referred to as the highest quality green tea. Unlike other teas, gyukuro comes from plants that have been entirely grown in the shade.

So irrespective of which green tea you choose, select the best quality available and affordable, invest in some stainless steel tea infusers (or use a tea infuser ball in a tea pot), and buy tea in loose leaves!

Tuesday, November 15, 2011

Secret 32: Have a Glass of Red Wine with Dinner

Have you heard of ‘the French paradox’? Although the French enjoy large quantities of saturated fat (think Brie, Camembert and cousins), they have a lower incidence of cardiovascular disease than Americans. Some researchers believe that the reason may be found in a glass of wine.
Wine has long been an important part of food culture (it's called 'wining and dining', isn't it?). The earliest production of wine took place about 8.000 years ago in a region now known as Georgia (not in the U.S.). Wine was already popular in ancient Greece and ancient Rome. The word ‘wine’ derives from the eponymous Latin ‘vinum’, which also means grape (vine).
In the case of wine, just like other foods I have written about, moderation, is important. As is quality. A reasonable dose of top quality wine may confer health benefits (we are well aware of the effects of an unreasonable quantity of alcohol). This is due to the presence of various chemical compounds in wine:
Polyphenols, more prevalent in red than white wine, are thought to protect against heart disease. Another health-supporting chemical in red wine is resveratrol. Resveratrol is manufactured by grape skins to ward off fungi. It is also found in the skin of other fruit such as mulberry. Muscatine grapes have resveratrol in the skin and the seeds.
The difference between red and white wine is that during the manufacture of white wine, there is minimal contact with the resveratrol-rich grape skins during fermentation. Rose has more resveratrol than white wine and less than red wine as it is made by blending the two.  
Muscatine grapes

What do we know about resveratrol? Experiments in rats and rabbits, but not yet in humans, show that resveratrol is anti-carcinogenic, anti-inflammatory, anti-viral (inhibits the herpes simplex virus types 1 and 2, the varicella-zoster virus, and some influenza viruses), lowers blood sugar and, in general, is good for the cardiovascular system. If the benefits of resveratrol are also available to humans, what is the best way to access this? Resveratrol concentration varies with the origin of the grape, its exposure to fungal infections, and the length of time the wine was in contact with grape skins during fermentation.  
Actually, red wine only has around one milligram per glass, or between 0.2 to 5.8 mg/liter, and most of this never reaches your blood. If you want to maximize your absorption of resveratrol from wine, allow the wine to stay in your mouth as the chemical is most easily absorbed across the mucous membranes in the mouth. The rest of your digestive system simply inactivates this chemical.

Or eat sprouted peanuts. Peanuts have 2.3 to 4.5 μg/g, and after sprouting 11.7 to 25.7 μg/g (and you avoid DUIs -- driving under influence of alcohol citations from traffic police). Chocoholics obtain resveratrol from cocoa powder, baking chocolate and dark chocolate. The concentration ranges from 0.35 to 1.85 mg/kg. Or just enjoy a glass of red grape juice (1.1 mg/l to 8.7 mg/l) or a handful of red grapes (1 cup or 160 g have 0.2 mg to 1.3 mg). Cranberry juice and grape juice have similar concentrations.
Other health-boosting chemicals in wine are antioxidants and flavonoids. One of the flavonoids in wine, procyanidin, has been shown to prevent blood vessel constriction. For a red wine with a procyanidin concentration double to four times that of other red wines, choose wines from Sardinia or the South of France. Procyanidins, just like resveratrol, are found in grape seeds. If you would like these chemicals sans alcohol, pour grape seed oil onto your salad.
Grape seed oil: another way to access beneficial chemicals in grape seeds
Another chemical, which Sally Beare applauds in red wine, is quercetin. This flavonoid is found in fruit, vegetables, leaves and grains. Studies however are, to date, inconclusive. Quercetin is neither especially beneficial nor harmful.
One less desirable ingredient in red wine are sulfites. These are a natural by-products of fermentation that extend the shelf life of wine. A compound closely related to sulfites, sulfur dioxide, is also added to enhance preservation. In some of us these compounds may result in minor irritations such as sneezing, hives and swelling of the throat (fortunately not anaphylaxis). Sulfites are considered one of the top nine allergens. Low sulfite-free wine is commercially available.
While some epidemiological studies claim that a moderate consumption of wine reduces the rate of death due to cardiovascular problems, other studies, such as the Million Women study, which followed the women in the U.K, concluded that a moderate intake of wine might actually increase breast, pharynx and liver cancer. The main investigator of the Million Women study, Prof. Valerie Beral, states that: “"It's an absolute myth that red wine is good for you." Are we comparing apples and oranges? The average supermarket wine consumed by the women in the Million Women study was not organic, not free of sulfites, low in procyanadin and tannins, and high in alcohol. If your average shopping basket contains battery-produced eggs, feedstock meat replete with hormones, GMO corn and soy ingredients, why should the wine be of higher quality
So if you drink alcohol, enjoy a top-quality glass of organic red wine once in a while. Moderation and quality. And if you do not drink alcohol, eat organic red grapes or add a few drops of organic grape seed oil to your dishes.

Wednesday, November 2, 2011

Secret 31: Beware the Pastry Counter

Secret 31 is an alphabet soup of biochemistry and undesirable conditions such as hypoglycemia, hyperinsulinemia, glycation, advanced glycosylation, insulin resistance, DHEA, adult-onset diabetes, eicosanoids, glycemic index, glycemic load and atherosclerosis (as predicted by the afore-mentioned hyperinsulinemia). To put it simply, Secret 31 takes a closer look at carbohydrates, classifies them by their glycemic index and advises against a high GI diet.

Off the glycemic index scale
What is GI or glycemic index? This index, which was invented in the early 1980ies by researchers at the University of Toronto, measures how quickly a carbohydrate releases glucose into the bloodstream. Two systems of measurement exist: the standard method equates glucose to 100, a less popular one equates white bread to 100 (and then glucose would be around 125). High GI foods have a GI above 70 on the standard index and include cereals, white bread, white rice, cakes, cookies, pop and sweets. Medium GI foods or those with a GI between 56 and 69 include basmati rice, whole wheat products, sweet potatoes (an Okinawan favorite), baked potatoes and pasta. Low GI foods have a GI of 55 or less and include most fruits and nearly all vegetables. Since meat and diary products are low in carbohydrates, their GI would be on the low end of the scale. Low GI carbohydrates take longer to digested and release glucose more gradually into the blood. In general, you want to avoid a diet of high GI foods as the constant blood sugar spikes can, over time, lead to hyperinsulinemia and adult-onset diabetes. The spikes are caused by the quick release and absorption of glucose which, in turn, leads to further sugar cravings.  You can reduce the GI of high GI foods by mixing them with foods low in GI i.e. a white baguette with cheese, or rice with fish and vegetables. Sometimes reaching for a high GI food is necessary, for example after intense exercise or if you are hypoglycemic (have low blood sugar) as your body needs to obtain energy quickly. However, most of the time a low to medium GI diet will provide plenty of energy. Note that the glycemic index applies to foods that yield about 50 g of available carbohydrate when consumed, thus the GI does not qualify the proteins and fats in your diet. Also note that foods that are not necessarily considered healthy, such as ice cream and chocolate cake have a low glycemic index due to their high fat content (38 and 37 respectively). In fact, many countries, despite having staple diet of high glycemic foods such as potatoes and rice, actually have a low incidence of diabetes. If you would like to find out more about GI, Sally Beare recommends Jack Challem's "Syndrome X". A more scientifically accurate book is Reaven's "Syndrome X: The Silent Killer". While GI may be useful to ascertain how quickly you can access glucose in a carbohydrate, this is not the optimal guide to choosing healthy food. Diets such as the South Beach diet use GI values. 

Maybe it is not the high GI value, but the presence of artificial flavors, colors and trans fats that are pose health hazards?

A more useful measure of the impact of a carbohydrate on your system is the glycemic load. In contrast to the glycemic index, the glycemic load also takes into account the amount of carbohydrate consumed. GL = GI x the amount of available carbohydrate in a 100g serving, in other words GL is a weighted GI value. For example watermelon has a high GI value (over 70), but since watermelon consists mainly of water and contains very little carbohydrate, its GL is low (5).  Also watermelon provides invaluable lycopene. If you avoid watermelon based on the GI, you are inadvertently denying yourself a wonderful source of lycopene. On the other hand the GL of white rice or a baguette is high (above 20).  But who eats a plain bowl of race or a 'naked' baguette? White rice tends to be eaten with fish or meat or tofu and vegetables, baguette with butter, cheese, or ham, so the overall glycemic load is lower and does not cause unhealthy sugar spikes (baguette with only honey and without butter would have a high GI!).  
Low GI and low GL.  More importantly - delicious!
Now that we have investigated GI and GL, let's explore some of the ailments Sally Beare mentions in Secret 31 and find ways to avoid them:

Hyperinsulinemia: a condition whereby excess levels of insulin circulate in the blood.  It is also known as 'pre-diabetes', insulin resistance or Syndrome X.  Recommended treatment includes exercise, reducing simple sugars, processed carbohydrates, potatoes and white bread and eating more vegetables and legumes.
Insulin resistance: a condition whereby insulin becomes less capable of reducing blood glucose. Obesity exacerbates this condition, especially visceral adiposity (fat around the mid-riff). Possible bad effects of a high-fat diet can be moderated by fish oil or other sources of omega-3 fatty acids. Despite a diet high in fats, Alaskan Eskimos have a low level of IR due to the presence of large quantities of fish oil in their diet. Habitual and excessive consumption of carbohydrates can lead to IR and studies have shown that trans fats are extremely deleterious. Alaskan Eskimos who switch from their ancestral diet to the Standard American diet exhibit the same Western diseases as the rest of the U.S. Exercise and weight loss are the first line of treatment.
Adult-onset diabetes or diabetes mellitus type 2: a metabolic condition with abnormally high blood glucose. In the U.S., 8% of the population is diagnosed with this condition. Helpful are exercise, dietary change such as increasing dietary fiber and reducing the consumption of trans fatty acids. Obesity, especially intra-abdominal fat, and smoking exacerbate the condition. Long-term complications include heart attacks, strokes, amputations, failing eye sight, kidney failure and testosterone deficiency in men. 
Universal symbol for diabetes
Atherosclerosis: a gradual and imperceptible hardening of the arteries that can suddenly result in a catastrophic blockage of an artery and cause a heart attack or stroke. Atherosclerosis is caused by an inflammatory reaction of the cell walls to retained low-density lipoproteins (LDLs). Inflammation, rather than fat or cholesterol is the cause of atherosclerosis. Once in the wall, LDLs may be oxidized by free radicals and become toxic. It is surmised that atherosclerosis is a vitamin C-deficiency disease. Vitamin C ensures a strong and flexible vascular system. Trans fats also play a harmful role.  In one study rabbits were fed heated soy bean oil (I assume GMO soybean) and displayed "grossly induced atherosclerosis and marked liver damage". Most of the oils sold in U.S. supermarkets are refined, bleached, deodorized, and gummed thereby making it much harder to detect rancid and thus harmful oils.  Exercise, loosing weight and not smoking help forestall atherosclerosis. Since cholesterol is an integral part of cell membranes and more than 80% is manufactured by the body, reducing dietary cholesterol has little effect. A lower external supply only makes the body create more cholesterol internally. More effective than changing the amount dietary fat or cholesterol  is reducing the intake of carbohydrates, especially simple carbohydrates and improving the quality of fat. Avoid trans fats and increase the intake of omega-3s. Also, avenanthramides, found in oats, have an anti-inflammatory effect and help prevent atherosclerosis (oats tend to be a good source of dietary fiber).  

So, in a nutshell:
  • maintain a healthy body weight
  • avoid continual blood sugar spikes
  • reduce the use of highly-refined oils (or most cheap non-expeller pressed vegetable oils)
  • include fish oils or other sources of omega-3 fats in your diet
  • avoid trans fats
  • enjoy the occasional dessert but do not make this a habitual part of your nutrition
Everything in moderation

Afterthought:  carrots originally were classified as having a high glycemic value.  Further studies, however, have reclassified carrots as having a low glycemic value.  If you come across a book that categorizes carrots as being high on the GI, then you are probably looking at old data.