Green Tea Plus Olive

Green tea comes as two very different products, a drink and a concentrated extract, and most of the questions depend on which one you mean. These are the questions our naturopaths ask in store.

A good fit if

• You're an adult who enjoys tea and wants catechins as a daily habit, not a dose
• You're fine with caffeine and count what you get from tea along with your coffee
• You like the calmer alertness people describe from the caffeine and theanine in the leaf
• You're thinking about a concentrated extract, will take it with food, and know what the label warns about
• Your health history is straightforward, with no liver concerns, no iron deficiency and no prescription medicines

Check with us first if

• You have iron deficiency or low ferritin, or take an iron supplement. Tea strongly reduces how much iron you absorb from plant foods and supplements, so keep it apart from iron-rich meals and iron tablets.
• You're sensitive to caffeine, or have anxiety, palpitations, trouble sleeping or high blood pressure. Medicines containing Camellia sinensis must declare their caffeine, capped at 400 mg a day.
• You're pregnant or breastfeeding. Labels on medicines containing caffeine must state that more than 200 mg of caffeine a day isn't recommended.
• You take nadolol, atorvastatin or raloxifene. NIH's NCCIH lists these as known interactions with green tea.
• You take warfarin, or anything that needs your vitamin K intake to stay steady. Tea leaf contains vitamin K.
• You take any medicine your liver clears with the enzyme CYP1A2. Higher-caffeine labels must carry an interaction warning.
• You also take a weight-management, pre-workout or greens formula. Many of them contain green tea extract and caffeine.
• You take any prescription medicine. A quick check with your doctor, pharmacist or our naturopaths first is the sensible move.

• Brewed leaf tea (bags or loose leaf). Best known for: The traditional way, and the one safety authorities view most favourably. Absorption: Only the water-soluble catechins. Brewing draws out just a fraction of what is in the leaf. Typical use: One to four cups a day. EFSA considers tea made the traditional way generally safe.
• Matcha (shade-grown leaf, stone-ground). Best known for: Drinking the whole leaf rather than an infusion of it, so nothing is left in the pot. Absorption: You swallow the powder, so for the same amount of leaf you get more catechins and caffeine than from brewed tea. Typical use: 1-2 g whisked into water or milk. Growing it in shade raises the theanine content.
• Concentrated extract tablet or capsule (standardised to catechins and EGCG). Best known for: Giving you in one tablet what would take many cups. This is also where the safety concerns sit. Absorption: High and variable, and higher again on an empty stomach, which is why Australian labels say to take it with food. Typical use: One tablet a day with food. Read the EGCG figure, not the 'equivalent to leaf' number.
• Decaffeinated green tea extract. Best known for: Catechins without the stimulant, for people who react to caffeine. Absorption: Unchanged, although decaffeinating removes some catechins too, by an amount that depends on the method. Typical use: When the caffeine, not the catechins, was the problem.
• Green tea in blended 'greens' powders and pre-workouts. Best known for: One part of a formula rather than the point of it. Absorption: Depends on the extract used, which is often not stated. Typical use: Add its caffeine and EGCG to everything else you have that day before calling it small.
• Topical green tea extract (skincare, soaps, balms). Best known for: Cosmetic use of the same plant extract on the skin. Absorption: Not taken by mouth. The Australian caffeine and liver rules apply to internal use. Typical use: A separate category from the tea and the tablet.

Reference values. None. Green tea is a plant food and herbal ingredient, not an essential nutrient, so the NHMRC sets no Nutrient Reference Value for catechins, EGCG or caffeine from tea. The Australian numbers that do exist are legal limits, not intake targets.

Typical supplemental range. Tea drinkers usually have one to four cups a day, which gives a catechin intake in the low hundreds of milligrams. Australian extracts go much higher. A single one-a-day tablet is often labelled as equivalent to 25 g of dry leaf and lists several hundred milligrams of catechins, much of it EGCG. The 'equivalent to leaf' figure describes how it was made. The catechin and EGCG figures tell you what you're actually taking.

Upper level. There's no NHMRC upper limit. Australia's limits are set in the permitted ingredients list (Schedule 1) at item 1134, and we quote them word for word here because rewording would change their meaning. Specific Requirements: "Caffeine is a mandatory component of Camellia sinensis. When the medicine is packaged for supply as a divided preparation and is for internal use or oral application, the medicine must not contain a concentration of total caffeine greater than 33%. When for internal use or oral application, the maximum recommended daily dose of the medicine must provide no more than 400 mg of total caffeine. When the medicine is packaged for supply as an undivided preparation and is for internal use or oral application, the medicine must not contain a medicine concentration of total caffeine greater than 1%. When the medicine is for internal use or oral application, a maximum recommended dose of the medicine must not provide more than 100 mg of total caffeine within a 3 hour period. ... The total concentration of flavour proprietary excipient formulations containing Camellia sinensis must not be more than 5% of the total medicine."

Worth knowing. What matters most is the form, not just the amount. EFSA found catechins from tea brewed the traditional way to be generally safe at the amounts Europeans usually drink. A cup of tea and a concentrated tablet are not the same thing. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Green tea, brewed, 250 mL: about 50-100 mg catechins and 30-40 mg caffeine
• Matcha, 1-2 g whisked into water: the whole leaf is consumed, so more catechins and caffeine per gram of leaf
• Black tea, brewed: same plant, fully oxidised: most catechins converted into theaflavins
• Oolong tea, brewed: partly oxidised; catechin content sits between green and black
• Decaffeinated green tea, brewed: caffeine largely removed; some catechins go with it

If any of these sound like you, talk to one of our naturopaths or your doctor before you start.

• Concentrated extracts must carry an Australian liver warning. Brewed tea does not.
• You have liver disease or have had liver injury from a medicine. Don't take concentrated extracts.
• Yellowing skin or eyes (jaundice), dark urine, unusual tiredness, nausea, loss of appetite, stomach pain or itching. Stop taking it and see a doctor.
• Children. Medicines giving more than 10 mg of caffeine in total per daily dose must be labelled 'Adults only'.
• Pregnancy and breastfeeding. Labels must state that more than 200 mg of caffeine a day is not recommended.
• You are low in iron or take iron supplements. Tea strongly blocks absorption of non-haem iron (from plants and supplements).
• You are sensitive to caffeine, or have anxiety, palpitations, trouble sleeping or high blood pressure. Caffeine is capped at 400 mg a day and 100 mg per 3 hours.
• You take nadolol, atorvastatin or raloxifene. NCCIH reports documented interactions with these.
• You take medicines processed by the liver enzyme CYP1A2. Higher-caffeine labels must carry an interaction statement.
• You take warfarin or another medicine that needs a steady vitamin K intake. Tea leaf contains vitamin K.
• Stacking it with pre-workouts or 'greens' powders. The caffeine and EGCG add up.
• Concentrated extracts must be taken with food where the Australian direction applies.
• Rare liver injury has also been reported after drinking tea, not only after taking extracts.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths first.