Does Green Tea Lose Antioxidants When Cold?

Green tea is widely consumed around the world and although it is typically enjoyed hot, it may also be served cold as a refreshing summer drink. While cold and hot green tea share many of the same health benefits, the antioxidant capacity of cold green tea may be less than that of hot green tea. Consult with your health care adviser prior to ingesting green tea as it may interact with certain medications.

Background Information

The leaves used to make hot and cold green tea are derived from Camellia sinensis, a plant indigenous throughout Asia. According to the University of Maryland Medical Center, the antioxidant compound found in green tea, primarily flavonoid and polyphenol catechins, supports the body in a number of ways. The antioxidants neutralize free radicals by donating an electron. This process allows the electrons to pair and stabilizes the free radicals so that they do not cause cellular damage. Without the neutralizing effect of antioxidants, free radicals may alter DNA, increase signs of aging and put your at risk of heart disease and several types of cancer.

Health Benefits

The University of Maryland Medical Center explains that the polyphenol compound in green tea may help to inhibit the growth of cancerous cells. This might explain why Asian countries that consume green tea on a regular basis, such as Japan, exhibit lower rates of cancer. Freshly brewed green tea may help help to slow the aging process, lower blood triglyceride and cholesterol levels, reduce tooth decay by inhibiting the growth of oral bacteria, as well as prevent liver damage. The liver is an organ that is subject to a higher level of oxidative damage because its primary role is to detoxify chemical compounds. Overuse of the liver, such as excessive consumption of alcoholic beverages, may have a damaging effect. According to healthcare experts at the University of Maryland Medical Center, a daily intake of 10 cups of green tea may significantly lower the risk of liver disorders.

Hot vs. Cold

Although green tea, in general, offers a vast array of health benefits, a 2001 study conducted by The Chinese University of Hong Kong suggests that freshly brewed green tea offers the greatest antioxidant support. According to the study, after a 7 hour time lapse post-brew, the antioxidant content of the green tea had a substantial drop of 20 percent. This may be explained by the fact that the antioxidants found in green tea are very reactive in that they oxidize quickly and easily form compounds when exposed to oxygen. You may still enjoy the antioxidant benefits found in a cup of cold green tea, just make sure you don't wait too long during the chilling process to ingest it. Adding a slice of lemon to the tea may help to slow the oxidation process and retain the antioxidants, as well as provide support for the immune system.

Considerations

While freshly brewed green tea offers the most health benefits, some people may prefer the convenience of commercial green teas. The antioxidant capacity of commercial green teas may not be as high as the antioxidant capacity of freshly brewed green tea as commercial green teas may have lived in storage for an extended period of time. According to a study published in the December 2008 edition of "Journal of Food Science," commercial green teas that have been stored for a period of 6 months exhibited degradation in green tea catechins. Furthermore, some commercial brands of tea may incorporate sugar into the blend to sweeten the product. Sugar has the ability to cause insulin spikes that may spur the growth of cancer cells, thereby diminishing the healthful effect of antioxidants.