Science – Adding Lemon Juice To Green Tea Enhances Its Health Benefits

Science: Adding Lemon To Green Tea Enhances Its Health Benefits Graphic © herbshealthhappiness.com.
Photo: Pixabay (PD)

Green tea has been a highly popular beverage since it was first discovered in ancient China. The date of the discovery of tea drinking is lost in the mists of time… but various legends place its origin from the reign of Emperor Shenning (2737 BC) to the Tang Dynstasy (618 to 907 AD).

In recent years green tea has “diversified”; it has become a flavor ingredient added to chocolate, cakes, and other various snacks and drinks sold in today’s markets. However, traditionally green tea is taken as a hot drink made from the brewing of dried “green” tea leaves in boiling water – and this simple herbal infusion is very probably the best way to gain its full health benefits.

What Is Green Tea?

Originating from Asia, green tea is made from the leaves of the same plant species Camellia sinensis as black tea. There are different types of green tea, such as Sencha from Japan, which is further classified into Bancha, Gyokuro, and the most popular one – Matcha. ^[1] Matcha in particular has the highest amount of caffeine compared to the other two, and has the highest amount of L-theanine. L-theanine is a type of amino acid that has been linked to improved cognition, emotional sense of well-being and sleep quality. ^[2]

Green Tea Catechins

When studying the health benefits of green tea, you will notice that catechins are often mentioned. Catechins are a type of polyphenol, which is a micronutrient found in plants that has significant anti-inflammatory and antioxidative abilities. ^[3] Data indicates that catechins are able to reduce oxidative stress in cells, helping fight cellular damage caused by aging and diseases such as heart disease, diabetes, and neurodegeneration. Catechins are not just found in tea but also other plant-based food and drink such as wine and cocoa-based products.

According to Musial, et. al., green tea is notably the best source of catechins, particularly unfermented green tea. Because of its high catechin content, green tea has been linked to a preventative effect against cancers that affect the lungs, esophagus, stomach, intestines, pancreas, breast, prostate, and bladder. ^[1]

Benefits Of Drinking Green Tea

Various studies have been published on the benefits of drinking green tea. ^[4] A population-based study conducted in Miyagi Prefecture found an inverse relationship between heart disease and green tea. ^[5] Older case-control studies in China showed that consumption of green tea was likewise inversely associated with gastric, pancreatic, colorectal, lung, and breast cancers. ^[6][7][8][9] Green tea was also able to reduce the risk for ovarian cancer in women in Sweden. ^[10]

Because of green tea’s antioxidative abilities, it has also been linked to decreasing the risk for dementia, one of the many health conditions associated with aging. In 2021, Unno and Nakamura published a study that reported how green tea was able to improve lifespan (because of a reduced risk of mortality due to disease) and prevent cognitive decline by suppressing brain dysfunction. ^[11]

Unno and Nakamura also link these health benefits to the catechins in green tea and how they are highly bioavailable when ingested. The researchers found that catechin bioavailability of green tea ranged anywhere between 40 to 62% when involving ring-fission metabolites (end products of the absorption process of catechins in the body) compared to typical values taken from urine, but that value varies largely among individuals.

So how does lemon play into all of this?

Lemon + Green Tea = Nutritional Powerhouse

In 2007, Green, et. al. focused on the digestive recovery or bioavailability of green tea catechins. ^[12] With the benefits of green tea being well established, understanding how our body absorbs the catechins needs to be studied further. The researchers focused on green tea extracts, specifically investigating four types of catechins: epicatechin (EC), epigallocatechin (EGC), epigallocatechin-gallate (EGCG), and epicatechin-gallate (ECG). Their study involved common commercial beverage additives and how they improved the digestive recovery of these catechins. The additives were citric acid, preservatives (BHT and EDTA), ascorbic acid, milk, and citrus juice.

Compared to what Uno and Nakamura published, this study focused on the lower bioavailability of catechins in urine and which additives helped boost the percentage of catechin recovery. Green, et. al. reported that less than 20% of catechins remained after digestion, with ECG and EGCG being the most sensitive, with less than 10 percent remaining after digestion. Here is how the percentages of catechin recovery improved after the additives were included in green tea:

Formulation made with half green tea and half milk, and their respective total catechin recovery percentages:

(1) Bovine milk – 52%
(2) Soy milk – 55%
(3) Rice milk – 69%

Formulation made with 30 grams of ascorbic acid and 250 ml of green tea significantly raised recovery percentages of the four types of catechins:

(1) EGC – 74%
(2) EGCG – 54%
(3) EC – 82%
(4) ECG – 45%

The best additive was citrus juice, improving catechin recovery as follows:

(1) EGC – 81-98%
(2) EGCG – 56-76%
(3) EC – 86-95%
(4) ECG – 30-55%

Citrus juice came out on top, with researchers formulating the solution by replacing 10-50% of the water used to brew the tea with juice. The higher the percentage of juice, the better the bioavailability of catechins when digested.

After testing the different kinds of citrus juice, the best results were seen with lemon juice, with 77.9 ± 2.9 total catechin recoveries. Lemon was followed by followed by: orange (71.2 ± 1.5%), lime (67.1 ± 6.8%) and grapefruit juice (62.3 ± 4.1%). These are numbers when the green tea formulation was made with 50% replacement of water with juice.

Health Benefits Of Lemons

An article published by the Cleveland Clinic recommended drinking lemon water in the morning before you start your day. Dr. Sukol mentions the following health benefits of lemon water: aiding digestion, improving hydration, weight loss, and antioxidation. She also mentions that lemons are an excellent source of vitamin C and potassium, and could also help prevent the formation of kidney stones. ^[13]

A study in 2004 found that citrus limonoids found in lemons could inhibit the development of oral tumors. ^[14] A comprehensive scientific report on the health benefits of lemon was published in 2021, highlighting the ability of citrus limon had significant antioxidant, antiulcer, antihelmintic, insecticidal, and anticancer abilities. ^[15]

So now it’s well established that green tea and lemon could be a powerhouse when taken together. If you like green tea, try adding lemon slices, lemon juice or replacing some of your water with lemon juice and see the health benefits yourself. You could also try other citrus juices for some interesting variety!