Health Benefits of Green Tea

Green tea
Green Tea

Tea is the most widely consumed beverage in the world, second only to water.  There are three main types of tea, green, black, and oolong.  Scientific studies suggest that green tea in particular has many health benefits.  Researchers believe the antioxidants, which are mostly polyphenols, in the tea leaves are responsible for the health benefits.

Green, black, and oolong teas are all derived from the leaves of the Camellia synensis plant.  This plant grows throughout Asia, parts of the Middle East, and Africa.  Green tea is prepared from unfermented leaves.  The leaves of oolong tea are partially fermented, and the leaves of black tea are fully fermented.  The more the leaves are fermented, the lower the polyphenol content and the higher the caffeine content.  Green tea has the highest polyphenol content, while black tea has 2 to 3 times the caffeine content of green tea.  Therefore green teas have the most nutritional benefits, followed by oolong and black teas.  You may have heard of white tea, which is simply the unfermented young leaves and buds of the Camellia synensis plant.

Reasons to Drink Green Tea

The health benefits of drinking green tea:

  1. Green tea is rich in antioxidants: The antioxidants found in green tea are mainly polyphenols.  A particular polyphenol, EGCG has been studied extensively, can powerfully destroy free radicals (metabolic byproducts that are chemically reactive and that can damage cells).  In research published in the European Journal of Clinical Nutrition, the polyphenols found in green tea are reported to be 6 times stronger than those found in black tea.
  2. Green tea lowers LDL (bad) cholesterol:  Research shows that green tea lowers LDL (bad) cholesterol and raises HDL (good) cholesterol in people.  One large-scale study found that men who drink green tea have lower total cholesterol than those who do not drink green tea.
  3. Green tea fights atherosclerosis: Large scale studies suggest the polyphenols in green tea help prevent atherosclerosis, the plaque buildup in your arteries.  The researchers believe that green tea fights atherosclerosis by lowering cholesterol and triglycerides.  Studies show that black tea has similar effects.  In fact they  estimate the rate of heart attacks decrease by 11 percent with consumption of three cups of tea daily.
  4. Green tea lowers risk of high blood pressure: A study published in 2004 reported that regular consumption of green and oolong tea reduced risk of developing hypertension.  Another study published in 2012 reported that regular long-term consumption of black tea lowered blood pressure.
  5. Green tea lowers cardiovascular disease risk: In a large-scale study, drinking three cups of green tea or black tea is associated with a 20 percent reduction in stroke risk.
  6. Green tea lowers cancer risk: Risk of cancer of the GI tract has been shown to be 17 percent lower in women who drink at least 3 cups of green tea a week.  There have also been lower risks associated with green tea consumption of the following cancers:  bladder, breast, ovarian, lung, pancreatic, prostate, and skin.
  7. Green tea strengthens your bones: The Harvard School of Public Health states that the tea polyphenols are thought to strengthen bones and protect against fractures.  Also a study published in Nutrition Research found the bioactive components of green tea may help decrease the risk of fractures by improving bone mineral density.
  8. Green tea helps protect your vision: A 2010 study reported that the components in green tea positively affected the tissues of the eyes, particularly the tissues of the retina.
  9. Green tea improves memory and cognitive function: Some of the compounds found in green tea boost certain brain tasks associated with working memory.  Working memory is the brain function that keeps in mind and manipulates multiple pieces of information simultaneously, helping you to plan ahead, organize information, solve problems and retrieve information, such as names.
  10. Green tea calms and relaxes you: L-theanine is the standout ingredient in green tea that has been studied for its calming effects on the nervous system.  A study published in Trends in Food Science & Technology found that green tea produces relaxing effects without drowsiness after just 40 minutes of ingestion.

Putting it into Practice

  • Brew it yourself: For the biggest benefit, definitely brew it yourself.  Bottled tea has significantly fewer polyphenols than home-steeped tea, plus added sugar that add unwanted calories.  You can serve it hot, or make a pitcher of home-brewed iced tea during the warmer months.
  • Watch the additives: It is not a good idea to resort to additives to make tea more palatable.  Be careful not to add spoonfuls of sugar to make tea go down easier.  The health benefits were observed for tea with little or no additives.  So maybe try a little honey or lemon to taste without compromising the purity of your tea, but stop there.
  • Daily dosage: The University of Maryland Medical Center recommends two to three cups of green tea per day.  This provides about 240 to 320 mg of polyphenols.
  • Try a healthy alternative: If you just can’t stomach green tea, you may want to try a healthy alternative – coffee.  Coffee is a perfectly reasonable and possibly equally healthful alternative.  Click here to read my article on coffee.
  • Caution if you are pregnant: Because of its caffeine level, green tea can be unsafe for pregnant women and their babies.  Always consult your doctor about consuming caffeinated beverages while pregnant.
  • Problem with iron: Drinking green tea may cause your body to absorb less iron, so it is best not to drink green tea with an iron-rich meal.  Rather drink green tea between meals.  Consult your doctor if you are anemic.
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Go Nuts – for Walnuts!

Walnuts closeup
Walnuts closeup

If you’ve been avoiding nuts because they are high in calories, stop now!  People who eat nuts in moderation (up to two ounces a day) can enjoy a variety of health benefits.  Walnuts are tree nuts, and they are the top dog of the nut world: they contain twice as many phytochemicals as their competitors.  Walnuts are the edible seeds of any tree of the genus, Juglans.  There are three main species of walnuts, the English walnut, black walnut, and white walnut.  The English walnut is the most widely consumed type of walnut in the United States.  Walnuts are a rich source of heart-healthy omega-3 fatty acids, folic acid, zinc, vitamin E and protein.

Reasons to Eat Walnuts

The health benefits of eating walnuts in moderation (one-to-two ounces a day):

  1. Walnuts are rich in antioxidants: Walnuts are the most antioxidant-rich nuts of all the nuts, including tree nuts and peanuts.
  2. Walnuts lower LDL (bad) cholesterol:  Walnuts contain a large percentage of unsaturated fats, particularly polyunsaturated fats.  They are also a rich source of the omega-3 fatty acid ALA.  ALA has been shown to lower LDL cholesterol and triglycerides.  A study published in the American Journal of Clinical Nutrition reviewed the heart-health benefits of walnuts on 365 participants, who were monitored during control diets and diets supplemented with walnuts.  Results showed walnuts cause a significantly greater decrease in total cholesterol and LDL cholesterol.
  3. Walnuts lower blood pressure: Walnuts contain the compound arginine which is converted to nitric oxide in the body.  This causes your constricted blood vessels to dilate easing blood flow.
  4. Walnuts lower cardiovascular disease risk: Several recent studies have linked higher intake of ALA to a reduced risk of cardiovascular disease.  One quarter-cup of walnuts provides all the ALA you need in a day.
  5. Walnuts strengthen your bones:  The ALA in walnuts is also good for your skeleton as they strengthen your bones.  In a study by researchers at Penn State University, 23 participants were fed four different diets over 6-week periods.  One of the diets was a high-ALA diet.  This high-ALA diet resulted in significantly less bone breakdown than the other diets.
  6. Walnuts lower type 2 diabetes risk: Researchers at the Harvard School of Public Health say that women who reported eating one ounce of walnuts at least five times a week reduced their risk of type 2 diabetes by 30 percent compared to those who rarely or never ate walnuts.
  7. Walnuts lower cancer risk: A 2010 scientific study by the University of Portugal concluded that the phenolic compounds and antioxidants in walnuts controlled the growth of human cancer cells.  Also the type of vitamin E found in abundance in walnuts has been shown to fight breast, prostate, and lung cancer.
  8. Walnuts lower mortality (premature death) risk: A nuts-and-longevity study published in 2013 in the prestigious New England Journal of Medicine involving 118,000 healthy volunteers found that people who ate one ounce (about a handful) of nuts (including walnuts) daily had a 20 percent lower death rate during the three-decade long study compared to participants who did not eat nuts.
  9. Walnuts help reduce stress: Recent scientific research shows that walnuts reduce blood pressure responses to stress in the laboratory.  The stressful situations include plunging your feet into an ice bath or delivering a speech in front of your peers.  Those who eat walnuts have lower blood pressure, both in response to that stress or when not under stress.  Since walnut oil and flax oil produced similar results, the researchers believe the benefits may be due to the omega-3 fatty acid ALA.
  10. Walnuts improve memory and concentration: A 2012 Journal of Alzheimer’s Disease report found that eating walnuts as part of a Mediterranean diet was associated with better memory and brain function.  The report states that the antioxidants in walnuts may help counteract age-related cognitive decline and even reduce the risk of neurodegenerative diseases, including Alzheimer’s.

Putting it into Practice

  • Moderate consumption: Because walnuts are high in calories, limit yourself to one to two ounces of nuts a day.
  • Use as a salad topping: You can add walnuts to salads instead of croutons and bacon bits.
  • Use on cereals: Add walnuts to oatmeal or any cereal.
  • Use in side dishes: Sprinkle chopped walnuts on sautéed vegetables.  Or stir them into cooked whole grains or chicken salad.
  • Try walnut butter: If eating walnuts by the handful is not your idea of a fun snack, then try making walnut butter.  You could stir it into smoothies, plain yogurt, or oatmeal.  You can also spread it on whole grain bread.
  • Home made trail mix: You can prepare a home made trail mix using walnuts, dried fruit (like cherries or raisins), 70 percent dark chocolate chips, and 100 percent whole grain pretzels.
  • Replace unhealthy snacks: Eat walnuts and other nuts instead of chips and less healthy snacks so that your daily caloric intake is not increased.
  • Store properly: Since walnuts are high in fat, they are prone to go rancid and spoil.  So store them in an airtight container in the refrigerator.