Is herbal tea real tea? Can tea really help reduce stress?

If you're loyal to the most consumed beverage in the world other than water, you've probably asked yourself those questions at some point.

According to Joyce Maina, founder and director of the Cambridge Tea Consultancy, tea has been consumed for over 5,000 years. It can help a person become invigorated but also enter a relaxed state.

"I am sure that when you have had a stressful day, all you want to do is settle down and relax and have a cup of tea," Maina said.

Now, what about the other benefits? Here are some facts about true tea:

True tea vs. herbal tea

True tea is made from the leaves of the plant camellia sinensis, most commonly known as the tea plant, whereas herbal teas are made using a combination of spices, flowers, bark and leaves belonging to edible, non-tea plants, according to the Republic of Tea.

Peter Goggi, president of the Tea Association of the U.S., says the plant was historically found in China and the northeast part of India.

"The British and Dutch were big about bringing tea around the world and that was really in the 1800s," Goggi said. "The Dutch certainly brought tea to Indonesia. Sri Lanka had tea planted in the 1870s. True tea has a history of being brought around the world."

The manufacturing origin of true tea is also different from herbal tea. Whereas individuals can create their own herbal blends, the starting material for true tea are the leaves of the camellia sinensis.

"That is why tea is purely sustainable because you are plucking the leaves every 10 to 15 days and in some parts of the world, 30 days, but you are never uprooting the plant," Goggi said.

There are four different types of true tea: green tea, black tea, white tea and oolong tea. The differences lie in how much the leaves of the camellia sinensis have been oxidized, a process that involves leaving the tea leaves in air temperature to dry and darken, according to artfultea.com.

The camellia sinensis plant isn't used in the making of herbal tea, meaning it can't be classified as real tea, Maina and Goggi told USA TODAY. That doesn't, however, diminish its health benefits or stress-relieving qualities, Maina said.

Stress-relieving components of tea

True tea does contain caffeine, a natural stimulant that energizes the brain. It also contains a unique amino acid, known as L-theanine, which relaxes the mind.

"I don't know any other product that does both at the same time," Maina said.

"It kind of triggers the body to be relaxed yet awake which explains why the British drink afternoon tea," Goggi said. "It is kind of that low period after lunch and before dinner and kind of a 'pick me up' period, but there is actually a reason for why it works."

There are different levels of L-theanine depending on which type of true tea is consumed.

Other health benefits of true tea

There are other areas where tea has been identified as potentially being helpful to the human body, according to Penn Medicine.

Green tea, in which leaves are typically processed with heat or steam, is high in flavonoids that can help reduce bad cholesterol and lower chances of blood clotting. A 2014 peer-reviewed study also shows that green tea can improve blood pressure.

Black tea, in which the leaves are dried and fermented, also has flavonoids that contain anti-inflammatory properties and support healthy immune function, according to Penn Medicine. This type of tea can also be used in baths if people have skin rashes and need to ease inflammation.

Oolong tea, which is partially oxidized, is high in an organic compound known as polyphenols that helps lower inflammation, according to Penn Medicine. It is also known for having L-theanine, which can help reduce the risk of Alzheimer's or Parkinson's disease.

  USA TODAY