Khaberni - Green tea is rich in catechin polyphenols, specifically known as Epigallocatechin Gallate (EGCG), a powerful antioxidant offering numerous health benefits.
Although green tea is beneficial for heart health, weight management, and other benefits, it’s important to consider that some of its compounds might not suit the body, and can affect the absorption and processing of certain medications, according to The Times of India.
1. Iron supplements
Iron deficiency is very common, especially among women, vegetarians, and the elderly. Therefore, it is often advised to consume iron supplements or prenatal vitamins rich in iron.
A study published in the journal Frontiers indicates that consuming green tea is linked to lower serum ferritin levels, especially in men and women after menopause, due to its high content of tannins and polyphenols. The effects are often stronger when green tea is consumed with or immediately after meals.
Also, green tea extract can be harmful to the liver in patients with certain genetic differences.
2. Vitamin B supplements
Green tea can interfere with the production of Vitamin B, especially B12 and folic acid. This is because the caffeine and polyphenols in it can reduce the body's ability to convert folic acid into its active form, which is essential for healthy cell growth.
As a precaution, it might be wise to take Vitamin B supplements at a different time from drinking green tea to support optimal absorption. A substance called tannin can inhibit the absorption of Vitamin B, especially B12. A study published in PubMed Central also shows that tannin-rich foods, such as tea or coffee, reduce the level of Vitamin B1 (thiamine).
3. Blood-thinning supplements
It is known that blood thinners, like warfarin, interact with Vitamin K, which plays a key role in blood clotting. Some dietary supplements, such as fish oil, garlic, and ginseng, have mild effects on blood fluidity, and when combined with green tea or its extracts, they might affect the effectiveness of blood clotting.
Green tea contains traces of Vitamin K, which can reduce the effectiveness of blood-thinning medications, so it is advisable to consult a doctor before adding green tea daily to your diet.
According to Cleveland Clinic, green tea impacts the function of blood thinners, as it is a source of Vitamin K. Therefore, always inform your treating physician of any supplements or herbal products you consume to avoid serious interactions with prescribed blood-thinning medications.
4. Stimulant-based supplements
Green tea contains caffeine and catechins, which are less than a regular cup of coffee. However, they might have a sufficient effect.
Theophylline and theobromine, which are mild stimulants, cause an increase in heartbeat and blood pressure when taken with green tea.
A study published in PubMed Central explained how catechins affect the body, and the effectiveness of green tea in reducing the effects of many drugs, including those for heart health, blood pressure, and cholesterol. In some cases, it may increase drug levels, such as with sildenafil.
Not all medications are affected, but drug interactions can affect the safety and efficacy of the medication. If a person regularly consumes green tea, it is advisable to consult a treating physician about the best time to take these supplements. However, sometimes a simple change, such as drinking green tea an hour before or after, can make a significant difference.
