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There is a popular belief that drinking tea shortly after meal can cause health problems and is also dangerous to anemic people.

Drinking tea just after a meal restricts the body's absorption of iron (Fe) consumed with the meal. [...] Tea or coffee consumed at least one hour after a meal does not interfere with iron absorption

Source: Today's Zaman

7 Things Not To Do After a Meal

Don't Drink Tea
  • Because tea leaves contain a high content of acid. This substance will cause the Protein content in the food we consume to be hardened thus difficult to digest however Japanese Green tea is known as a drink which has many benefits for your health.

Source: Health Time

I just want to know if this claim is true and if it is, exactly what kinds of problems it can cause?

Ajay Chadha
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2hamed
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    Actually for various types of anemia (eg. thalassemia) high iron intake is unhealthy. And these types of anemia in developed countries are way more common than iron deficiency anemia. – vartec Mar 28 '12 at 15:31
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    This belief may be popular in certain parts of the world, but is not in say Japan, where it is common to have tea after a meal. –  Aug 03 '14 at 09:54
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    I can't find anything specific on tea and protein digestion, but the stomach is far more acidic than tea, and pepsin (the first protein digesting enzyme) requires this acidic environment to work. Hence I would have to say that this contradicts known science. However my answer explaining this got deleted as theoretical. – Paul Johnson Oct 29 '18 at 14:36

2 Answers2

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Drinking tea immediately after a meal can inhibit iron absorption from vegetable sources, however it does not inhibit iron absorption from cooked meat.

Source - The effect of tea on iron absorption

The effect of tea on iron absorption was studied in human volunteers. Absorption from solutions of FeCl3 and FeSO4, bread, a meal of rice with potato and onion soup, and uncooked haemoglobin was inhibited whether ascorbic acid was present or not. No inhibition was noted if the haemoglobin was cooked.

The effect on the absorption of non-haem iron was ascribed to the formation of insoluble iron tannate complexes. Drinking tannin-containing beverages such as tea with meals may contribute to the pathogenesis of iron deficiency if the diet consists largely of vegetable foodstuffs.

Community
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Tom77
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According to this study published in the American Journal of Clinical Nutrition (and referred to in this medical news article), consuming tea with meals has a significant effect on iron absorption.

This study shows that tea consumed simultaneously with an iron-containing porridge meal leads to decreased nonheme iron absorption and that a 1-h time interval between a meal and tea consumption attenuates the inhibitory effect, resulting in increased nonheme iron absorption. These findings are not only important in relation to the management of iron deficiency but should also inform dietary advice, especially that given to those at risk of deficiency.

However, the same study reports that if tea is consumed an hour or more after the meal, the inhibitory effect of tea on iron absorption is attenuated. It is therefore recommended to have at least an hour gap between meals and tea

Oddthinking
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so2
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    If that's a problem, then pretty near everybody in the US south ought to be anemic. Pretty much everybody drinks ice tea with their meals. – JRE Oct 29 '18 at 08:34
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    @JRE: How does so2's answer merit that comment but Tom77's answer doesn't? The effect is apparently well-documented. No-one said that the effect is instant anemia. Also, I seem to remember that the US south has no shortage of cooked meat in its cuisine... – DevSolar Oct 29 '18 at 08:48
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    [Welcome to Skeptics!](http://meta.skeptics.stackexchange.com/questions/1505/welcome-to-new-users) It is probably worth emphasizing that this study only refers to non-haem iron (e.g, iron derived from plants). Haem iron from meat is absorbed differently. – Oddthinking Oct 29 '18 at 12:56
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    @JRE: In addition to Oddthinking's point, any harm will depend on the amount of iron that is still absorbed. If your food contains twice as much iron as you need, but you can only absorb 50% of it due to tea drinking, you are still going to get enough. – Paul Johnson Oct 29 '18 at 13:37
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    And, further to @PaulJohnson's comment, the typical Western diet contains a high proportion of iron-supplemented foods, with the result that most of us in the US and Europe are consuming far, far more iron than we need, so reduced iron absorption is not an issue unless you are already specifically at risk of iron deficiency. (On the contrary, unless you have haemochromatosis, your body is already down-regulating iron absorption to avoid taking up too much of it, regardless of whether you drink tea with meals or not.) – Dave Sherohman Oct 31 '18 at 10:31