Reader Mr. Weng used the website’s “Contact Me” on 2023-10-7 to inquire:
『Professor Lin: He is always your loyal reader, respects your great works, and is also a fan of this website’s long-term follow-up. I am a serious lover of coffee and must drink coffee every day. A report on research in 2023 is as follows: "The research team of Johns Hopkins University in the United States collected two large-scale studies, a total of 4,854 subject data. In both studies, more than 50% of people drank coffee every day, and more than 30% drank more than 2 cups of coffee a day. As a result, 20 overlapping greases were found. The team further analyzed and found three greases related to kidney function, two of which were harmful to the kidneys;… "But some medical related research and the views of prestigious doctors: Coffee is beneficial to the kidneys. The two are completely different in their opinion, making people feel unsuitable. Is there a more correct and reliable practical medical study: the impact of coffee on the kidneys. Thank you Professor Lin for your gratitude. 'I used the three keywords coffee (coffee) and kidney (kinema) and Hopkins (kinema) to search for Google. The first information I found was an article that coffee is beneficial to the kidneys. Please read the Coffee consumption linked to reduced risk of acute kidney injury, study finds published by Johns Hopkins University on June 2, 2022 (coffee consumption linked to reduced risk of acute kidney injury, study finds (study found that drinking coffee can reduce the risk of acute kidney injury).
{Its first and second paragraphs (combined) are: "If you need another reason to start a new day with a cup of coffee, a recent study by a medical researcher at Johns Hopkins University shows that drinking at least one cup of coffee a day can reduce the risk of acute kidney injury compared to those who don't drink coffee. 5 The results of a study published in the journal Kidney International Reports on May 5 showed that people who drink any amount of coffee every day had a 15% reduction in acute kidney injury risk, with the largest decrease in risk among those who drink two to three cups of coffee a day (22%– 23%). ”
The study mentioned in this paragraph is Coffee Consumption May Mitigate the Risk for Acute Kidney Injury: Results From the Atherosclerosis Risk in Communities Study (Coffee drinking can reduce the risk of acute kidney injury: the results of a study on the risk of sclerosis of community porridge). Its conclusion is that higher coffee intake is associated with lower acute kidney injury risks and can provide opportunities to protect the heart and kidney through diet. It is necessary to further evaluate the physiological mechanism of coffee on heart and kidney protection.
Since Google searches can't find the study the readers said, I used the same three keywords to search PubMed, and found the Metabolites Associated with Coffee Consumption and Incident Chronic Kidney Disease published in 2021.
The article is definitely the study of Johns Hopkins University as reader Mr. Weng. In fact, this article is from the same research team (the authors have different orders). In other words, the same team published two seemingly opposite essays in 2021 and 2022. What surprised me even more was that the 2022 article did not mention the 2021 article at all.
Regardless, the focus of that 2021 article was that "the receptacles of two coffees may be harmful to the kidneys", but it did not say that drinking coffee can be harmful to the kidneys. In contrast, the 2022 paper said bluntly that "higher coffee intake is related to lower acute kidney injury risks." Therefore, as far as "drinking coffee is related to kidney health", the article in 2021 is intermittent, while the article in 2022 is direct.
Next, I simply browsed all the articles about "coffee and kidney" in the past three years, and saw three more interesting articles:
2021: The association between coffee and caffeine consumption and renal function: insight from individual-level data, Mendelian randomization, and meta-analysis (the association between coffee and caffeine intake and kidney function: from personal-level data, Mendelian randomization and combined analysis). Conclusion: We found no significant relationship between coffee intake and kidney function or chronic kidney disease risks.
2023: CYP1A2 Genetic Variation, Coffee Intake, and Kidney Dysfunction.
This article first introduces that caffeine is detoxified by cytochrome P450 1A2 (CYP1A2), so the transmission of CYP1A2 may affect the clearance of caffeine, which may change the relationship between coffee intake and kidney disease. Through a survey of 1,180 people, the paper concluded that caffeine-containing coffee was associated with increased risk of albuminuria, hyperfiltration and hypertension in people with slow caffeine retention (rs762551 AC and CC genotypes), suggesting that caffeine may have a role in the treatment of kidney disease in susceptible people.
2023: Association of habitual coffee consumption and kidney function: A prospective analysis in the Rotterdam Study. Conclusion: We have observed the beneficial connection between coffee and over 70 and obese participants to delay kidney function decline. Similar trends were observed in patients with type 2 diabetes, and similar trends were observed in people with smoking quash.
In short, as far as the articles I have read, including the five above, does not have a clear evidence that drinking coffee is beneficial or harmful to the kidneys, but the beneficial trend is obvious.
Original text: Coffee hurts the kidneys, Johns Hopkins' researchEditor: Gu Zihuan