Can a cup of coffee a day cause anemia? Nutritionists reveal the truth!

In recent years, more and more people have begun to like drinking coffee. Industry reports show that in 2021, the number of coffee consumers in China will reach 350 million.

However, a recent trending search has caused many people's hands to tremble slightly while drinking coffee——

#The cause of your anemia may be related to coffee # Coffee will hinder the absorption of iron ions, and lack of iron ions in the body can easily cause anxiety and insomnia.

Image source: Weibo screenshot

Many netizens shared their own experiences in the comments: "The physical examination report showed that my hemoglobin level was only 91. I have been drinking a cup of coffee almost every day for the past six months."

"Girls must drink less coffee! I often drink coffee since I started working. Recently, I feel tired. I am out of breath after climbing four floors. I can't get enough sleep every day. I went to see a doctor and he said I have anemia and can't drink coffee and tea."

Some people also said that they finally understood why "Latte" is called Latte, because "it will take away the iron"...

Image source: Weibo screenshot

Does coffee really affect iron absorption and cause anemia? Can I still drink coffee in the future ?

Does coffee affect iron absorption?

The answer is: Yes, but don't worry too much .

One reason is that coffee only affects the absorption of non-heme iron , the kind found in grains and vegetables, but has no effect on the heme iron found in meat (beef, lamb, fish and poultry).

Here we need to explain the meaning of "non-heme iron" and "heme iron":

Iron is a very important trace element for the human body. Iron sources can be divided into two categories: heme iron and non-heme iron .

Heme iron is only found in animal foods, such as animal liver, animal blood, red meat, poultry, etc. Non-heme iron mainly comes from plant foods, such as spinach, beans, etc.

Although both non-heme iron and heme iron can supplement our iron, the effects are quite different. Heme iron, which is iron from animal food sources, can be better absorbed and utilized by the human body. The absorption rate of non-heme iron is very low and it is more difficult to be absorbed and utilized by the human body .

While plant ingredients such as polyphenols, caffeine, and phytic acid in coffee give coffee a wonderful taste, they also combine with iron, snatching the position of iron ions, reducing the iron absorption rate, and thus affecting the absorption of non-heme iron .

One study found that drinking coffee while eating a burger reduced the absorption of non-heme iron from the burger meal by 39% per cup of coffee.

The good news is that there are many sources of iron in our diet, and caffeine intake does not have a significant effect on the body’s overall iron absorption . In fact, coffee only contributes about 6% of the iron in a meal[1].

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Another reason is that the effect on iron absorption also depends on when you drink coffee .

Because coffee only hinders the absorption of some iron when you take it, it does not cause iron loss in the body. Studies have found that drinking coffee one hour before a meal has no effect on iron absorption [2].

Can drinking coffee regularly cause anemia?

In fact, studies in the United Kingdom[3], South Korea[4], and France[5] have found that caffeine intake from coffee or tea does not cause iron deficiency and anemia in healthy people.

In 2021, the average coffee consumption per capita in China is only 9 cups per year, which is much lower than that in the United States, Japan and other countries (e.g., the United States is about 340 cups per year, and Japan is about 293 cups per year). The average per capita coffee intake in the United States and Japan is much higher than that in my country, but their anemia rate is lower than ours.

United States : A survey showed that the rate of iron deficiency anemia among women aged 12 to 21 was 6.3%[6], while another survey showed that the rate among women aged 15 to 29 was 7.1%[7].

Japan : In the general population of Japan, the anemia rate among women aged 20-29 years is 7%[8].

China : According to the Report on the Nutrition and Chronic Disease Status of Chinese Residents (2015), the anemia rate among Chinese residents aged 6 and above is 9.7%. Data from the 2010-2012 monitoring of the nutritional and health status of Chinese residents showed that the total anemia rate among urban and rural residents in China was 9.7%, including 7.0% for males and 12.6% for females[9]. Another data showed that the anemia rate among Chinese women aged 18-45 was 15.67% [10].

In general, as long as you can ensure that you get enough iron in your daily diet, such as eating more lean meat, and eating fruits and vegetables separately from coffee (vitamin C in fruits and vegetables can promote iron absorption), you don't have to worry about drinking coffee causing anemia.

In real life, few people suffer from anemia due to drinking coffee. Many people suffer from iron deficiency anemia not because of drinking coffee, but because they do not consume enough iron.

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How to drink coffee healthily?

For healthy people, regular coffee drinking does not lead to iron deficiency and anemia. Therefore, coffee can still be consumed, but it is best not to exceed 4 cups per day [11].

However, for people with iron deficiency anemia, it is recommended that:

1. Try not to drink coffee while eating. It is recommended to drink it one hour after a meal .

2. Coffee only affects "non-heme" iron and has no effect on "heme" iron. If you drink coffee, you can eat more lean meat, fresh fruits and vegetables. You can also take iron and vitamin C supplements appropriately to ensure that you can take in enough iron raw materials.

3. If you really want to drink it but are worried about affecting the absorption of iron, you can also choose decaf coffee .

References

[1] Sevgi Kolaylı, et al.Does caffeine bind to metal ions?.Food Chemistry,Volume 84, Issue3,2004,Pages 383-388.

[2] Morck TA, Lynch SR, CookJD. Inhibition of food iron absorption by coffee. Am J Clin Nutr. 1983Mar;37(3):416-20. doi: 10.1093/ajcn/37.3.416. PMID: 6402915.

[3] Nelson M, Poulter J. Impact of tea drinking on iron status in the UK: a review. J Hum Nutr Diet. 2004 Feb;17(1):43-54. doi: 10.1046/j.1365-277x.2003.00497.x. PMID: 14718031.

[4] Lee J. Association between Coffee and Green Tea Consumption and Iron Deficiency Anemia in Korea. Korean JFam Med. 2023 Mar;44(2):69-70. doi: 10.4082/kjfm.44.2E. Epub 2023 Mar 20. PMID:36966735; PMCID: PMC10040266.

[5] Mennen L, Hirvonen T,Arnault N, Bertrais S, Galan P, Hercberg S. Consumption of black, green and herbal tea and iron status in French adults. Eur J Clin Nutr. 2007Oct;61(10):1174-9. doi: 10.1038/sj.ejcn.1602634. Epub 2007 Feb 7. PMID:17299492.

[6]JAMA. 2023;329(24):2191-2193. doi:10.1001/jama.2023.8020

[7] Le CH. The prevalence of Anemia and moderate-severe Anemia in the US population (NHANES 2003-2012). PLoSOne. 2016;11(11):e0166635.

[8] Kusumi E, Shoji M, EndouS, Kishi Y, Shibata T, Murashige N, et al. Prevalence of anemia among healthy women in 2 metropolitan areas of Japan. Int J Hematol. 2006;84(3):217–9.

[9] Li Min, Hu Yichun, Mao Deqian, et al. Study on the prevalence of anemia among Chinese residents [C]//Chinese Nutrition Society, Institute of Nutrition and Health, Chinese Center for Disease Control and Prevention, Institute of Food and Nutrition Development, Ministry of Agriculture, Institute of Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. Proceedings of the 13th National Nutrition Science Conference of the Chinese Nutrition Society and the Global Chinese Nutrition Scientists Conference. [Publisher unknown], 2017: 2.

[10] Lu Jiaxi, Chen Jing, Li Min, et al. Anemia, vitamin A and vitamin D nutritional status of adult women in China from 2010 to 2012[J]. Acta Nutrimenta Sinica, 2020, 42(04): 325-330. DOI: 10.13325/j.cnki.acta.nutr.sin.2020.04.003.

[11] China Food and Nutrition Information Exchange Center, Institute of Nutrition and Health, Chinese Center for Disease Control and Prevention, Health Communication Branch of Chinese Preventive Medicine Association, etc. Scientific consensus on coffee and health[J]. Chinese Journal of Preventive Medicine, 2018, 52(11): 1115-1116. DOI: 10.3760/cma.j.issn.0253-9624.2018.11.004.

[12] Expert consensus on nutritional prevention and treatment of iron deficiency anemia[J]. Journal of Nutrition, 2019, 41(05): 417-426.

Author: Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center

Reviewer | Chen Ran, Associate Research Librarian (Science Communication) / Senior Engineer, COFCO Nutrition and Health Research Institute