Green Tea May Combat Rheumatoid Arthritis

Antioxidants may reduce the severity of RA symptoms

Green tea may help prevent and treat rheumatoid arthritis (RA). That's believed to be due to the antioxidants it contains.

These antioxidants are called catechins. Polyphenols are a type of catechin.

These substances stabilize molecules—free radicals—that have become unstable for a variety of reasons. Free radicals lead to oxidative stress. They're implicated in many diseases, including RA.

This article looks at why green tea helps with RA, how to use it, other teas that may (or may not) have similar effects, dosages, and side effects. It'll also help you select and brew green tea and decide whether supplements are a better option.

Green Tea Catechins and RA

Inflammation is part of your body's healthy response to trauma. In diseases like RA, though, it becomes chronic. It then causes significant pain and damage.

Two catechins in green tea have been found to interfere with the inflammatory processes. They're called:

  • EGCG (epigallocatechin 3-gallate)
  • EGC (epicatechin 3-gallate)

The bulk of green-tea research has focused on EGCG. Studies show it's the more effective one.

EGCG also appears to have better bioavailability, which is how well your body can absorb and use it. It has between 25% and 100% more antioxidant power than vitamins C and E.

One researcher called EGCG "one of the leading plant-derived molecules studied for its potential health benefits." They said EGCG makes up about 63% of the total catechins in green tea.

Recap

Catechins are a type of antioxidant. Green tea contains two catechins—EGCG and EGC—that help block the inflammatory process. EGCG is believed to be the more effective and more prevalent one. It's been studied the most and shows promise.

Synovial Fibroblast Activity

RA involves inflammation that damages the lining of your joints—the synovium. In the synovium is a type of cell called a fibroblast.

In RA, synovial fibroblasts are produced at high levels and destroy the cartilage around joints. This causes pain and disability.

Scientists theorize the surge in fibroblasts is caused by several cells involved in the overactive immune system of RA. These include:

These excess fibroblasts then influence the activity of immune cells—leukocytes, cytokines, and chemokines. That allows the fibroblasts to invade the cartilage and begin destroying it.

Some scientists believe the fibroblast signaling process may be a valuable target for future drugs.

A 2018 review of natural products for treating autoimmune arthritis back this. It cites a rat study in which green tea significantly reduced levels of TNFα and IL-1ß. It also decreased the activity of certain chemokine receptors in the joints.

A 2017 study of RA fibroblast activity used human synovial tissues from the knees and hips. Researchers found both EGCG and EGC inhibited IL-1ß activity, but EGCG was more effective.

Other Benefits for RA

Other laboratory research has noted that:

  • EGCG appears to impact several types of T-cells. Those are also part of RA's immune over-response.
  • Green tea may normalize metabolic functions that tend to be abnormal in arthritis.
  • In addition to catechins, green (and black tea) contains an amino acid called L-theanine, which has numerous health benefits for stress, mood, and sleep (in general, not just for RA).

Recap

Joint damage in RA is driven by immune-system cells called TNFα and IL-1ß. They lead to the over-production of fibroblasts. Fibroblasts influence other immune cells, which allows it to get into the cartilage and destroy it.

In a rat study, green tea has lowered levels of TNFα and IL-1ß. A study on human tissues showed EGCG and EGC inhibited IL-1ß activity.

Green tea may also impact T-cells, correct the metabolism, and improve stress response, mood, and sleep.

Research on Dietary Use

A large-scale, real-world study in 2020 looked at green and black tea consumption and RA. Researchers analyzed data from more than 700 participants.

They concluded people who drank a lot of tea had less active RA than those who drank less or no tea. This trend was strongest in women, non-smokers, and people older than 60.

A 2020 review of literature on RA and diet found evidence that:

  • Black tea had an anti-inflammatory effect.
  • It decreased levels of several markers of RA, including CRP levels, and the aggregation/activation of leukocytes and platelets.
  • More than three daily cups of tea reduced the risk of developing RA.
  • Green tea had protective effects against inflammatory diseases like RA, plus heart disease, neurodegenerative disease, and some types of cancer.

A 2018 study with a thousand participants found green tea and coffee both appeared to help prevent RA.

Green Tea vs. Other Teas

Green, white, and black teas come from the Camellia sinensis plant. The only difference between them is when they're harvested:

  • White tea is harvested earliest
  • Green is harvested a little later
  • Black is harvested later still

The earlier the harvest, the more antioxidants and less caffeine it has. Animal studies have shown the anti-inflammatory effect of green tea extract to be superior to that of black tea extract.

Green, black, and white teas come in different varieties. Because they're all from the Camillia sinensis plant, they contain the same polyphenols, although the amounts may differ.

TEA VARIETIES COLOR/HARVEST TIME
Jasmine Green
Matcha Green
Oolong Between green and black
Assam Black
Ceylon Black
Chai Black (blended with spices)
Pu-erh  Later than black, naturally fermented

Herbal teas (also called tisanes or herbal infusions), rooibos (red tea), and honeybush teas don't come from the Camellia sinensis plant. Some of them may offer health benefits. However, they don't contain the same polyphenols or effects as the varieties above.

Dosage and Intake

Safe and effective dosages of green tea and EGCG haven't been established.

Several studies recommend EGCG dosages between 90 milligrams (mg) and 300 mg a day. Since a cup of green tea contains between 60 mg and 125 mg, you can get the target amount in a few cups a day.

Research suggests that doses of up to 800 mg a day may be safe. But side effects are more likely at this level.

Green tea extract may be more effective when taken on an empty stomach.

Selecting and Brewing Green Tea

For quality green tea, avoid grocery-store tea bags. They tend to be lower quality and not as fresh as other teas. Look for better quality teas in:

  • Local tea shops
  • High-end grocery stores, specialty markets
  • Asian grocery stores
  • Online tea shops and vendors

You may be able to find high-quality tea bags. But loose-leaf teas generally yield better results.

It's hard to gauge the medicinal value of pre-bottled tea. You likely won't be able to get information on tea quality, steep time, or catechin levels. You may also get a lot of sugar.

For medicinal use, it's generally best to brew your own tea or take supplements.

To Prepare Green Tea

Brewing green tea properly can maximize its benefits.

  • Water should be simmering, not boiling. Between 150 and 180 degrees Fahrenheit is ideal.
  • Follow the steep time for the variety you get (if noted). Generally, green teas have a short steep time between 20 seconds and four minutes.

Green tea may become bitter if it steeps for too long. If you're not pleased with the flavor, try a shorter steep time.

Consistent Dosage

It's difficult to determine the specific amount of catechins you're getting from tea. To get a consistent therapeutic dosage, green tea extract supplements may be a good option.

Buying Green Tea Supplements

Supplements aren't regulated by the U.S. Food and Drug Administration (FDA).

Always read the labels on supplements. They'll tell you the strength of the product plus any additional ingredients it contains.

To make sure a supplement contains the amounts of catechins and caffeine listed, look for a seal of approval from a third-party testing organization. ConsumerLab is a common one.

That lets you know the label is accurate and the product isn't contaminated in potentially harmful ways.

Recap

Studies show dietary use of green tea can be effective against inflammation. Three or more daily cups may reduce your risk of RA and protect you from heart disease, degenerative brain disease, and certain cancers.

Green tea is harvested earlier than black tea but later than white tea. Earlier harvest means more antioxidants and less caffeine.

Dosages of green tea aren't established but studies have used between 90 mg and 300 mg a day. You can get that amount from a few cups a day.

Select high-quality tea and brew it properly (simmering water, short steep time). If you choose supplements, look for one with independent testing, such as from Consumer Lab.

Side Effects and Warnings

Even natural products can cause side effects. Any time you add something to your regimen, you should know and watch for the potential side effects.

Talk to your doctor before taking anything, as it may not be safe for you based on your medical history or other treatments.

Possible side effects of green tea tend to be more common at higher dosages. Most of them have to do with caffeine. They include:

  • Anxiety
  • Tremors
  • Irritability
  • Trouble sleeping

Green tea is less likely to cause these symptoms than other caffeinated beverages. If you're sensitive to caffeine, you may want to look for decaffeinated options.

Liver toxicity has been noted in animal studies. But that's only at doses that far exceed recommended human intake. Still, if you have liver disease, talk to your doctor about the potential risks.

Little is known about green tea's impact during pregnancy and lactation. One animal study suggests it may cause abnormal fatty tissue deposits in the mother and baby.

The caffeine in green tea may also be a concern. If you're pregnant, trying to get pregnant, or breastfeeding, talk to your doctor about green tea before using it.

Tannic acid in green tea may stain your teeth.

Drug Interactions

Green tea may cause other medications to work differently than intended. It might lessen the effects of:

Because of the stimulating effect of green tea, you shouldn't combine it with other stimulants.

Summary

Catechins in green tea appear to help prevent and relieve symptoms of RA. Researchers believe this is due to catechins that block the inflammatory process and cells responsible for immune over-activity.

Dietary green tea can be effective medicinally. Green is generally more effective than black tea because of its different harvest time and antioxidant levels. You can get medicinal levels from a few cups a day.

Select high-quality tea and be sure to brew it properly (simmering water and short steep time.) Or, for a more consistent dosage, choose a high-quality green tea extract supplement.

Check with your doctor before using green tea medicinally. Watch for side effects and be aware of any possible drug interactions.

A Word From Verywell

RA is a serious and potentially debilitating disease. While green tea may help prevent and treat it, you shouldn't use green tea in place of conventional medicine. It's best considered a useful addition to your treatment regimen.

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