For years, health experts cautioned against drinking too much coffee, citing concerns about heart disease. But recent studies have uncovered surprising health benefits. Unlike earlier research, modern studies account for factors like age, sex, BMI, physical activity, smoking habits, and family history of cancer. This helps isolate coffee’s direct impact on health.
A major UK study from 2022 found that adults who consumed more unsweetened or sugar-sweetened coffee had a lower risk of cancer-related and all-cause mortality over seven years. However, coffee with artificial sweeteners showed no such benefit.
Coffee and Colorectal Cancer
Meta-analyses, which combine results from multiple studies for greater accuracy, suggest that drinking four or more cups of coffee daily may reduce the risk of colorectal cancer by 11–24%.
Coffee and Endometrial (Uterine) Cancer Risk
Data from the Nurses’ Health Study, which included 67,470 women, revealed that drinking four or more cups of coffee daily may significantly lower the risk of endometrial cancer. Women who consumed this amount were 25% less likely to develop the disease compared to those who drank just one cup a day, and 30% less likely than non-coffee drinkers.
Notably, decaffeinated coffee offered the same protective effect, while caffeinated tea showed no benefit.
Coffee and Liver Health: Cancer and Cirrhosis
Studies show a strong link between coffee consumption and reduced risk of liver cancer and cirrhosis. People who drank 3–4 cups daily had about half the risk of developing the most common form of liver cancer compared to non-drinkers, while those drinking 5+ cups had just one-third the risk.
A Japanese study even reported a 76% reduced risk in heavy coffee drinkers, especially among those with hepatitis C.
Coffee also appears to protect against cirrhosis. An 8-year study of 120,000 Americans found a 22% drop in cirrhosis risk for each daily cup of coffee. In Norway, a 17-year study showed that people drinking two or more cups daily were 40% less likely to develop the condition.
Coffee and Skin Cancer Prevention
Research based on data from the Nurses’ Health Study and the Health Professionals Follow-up Study revealed that drinking more than three cups of caffeinated coffee per month was linked to a 17% lower risk of basal cell carcinoma—the most common and least harmful skin cancer. Decaffeinated coffee showed no such benefit.
A 2014 study also found that consuming four or more cups of coffee per day lowered the risk of malignant melanoma—the deadliest form of skin cancer—by 20%. However, coffee intake had no effect on melanoma in situ, a less severe form.
Important: While coffee may help reduce cancer risks, limiting sun exposure and UV protection remains the most effective way to prevent skin cancer.
Coffee and Type 2 Diabetes
In Finland, where coffee consumption is among the highest globally, a study of 14,000 people revealed dramatic results: men who drank 10 or more cups of coffee daily had a 55% lower risk of developing type 2 diabetes compared to those drinking two or fewer cups.
Women who consumed 10+ cups daily had a staggering 79% lower risk. Similarly, a Finnish study of 5,000 sets of identical twins found a 35% reduced risk of type 2 diabetes in individuals drinking seven or more cups of coffee daily.
Coffee and Parkinson’s Disease
A study involving over 8,000 Japanese-American men found that those who consumed four and a half cups or more of coffee daily were three to five times less likely to develop Parkinson’s disease compared to non-coffee drinkers over a 30-year period.
Coffee and Suicide Prevention
Research shows a potential link between coffee consumption and lower suicide rates. A 10-year study of 128,000 individuals in California found a 13% decrease in suicide risk for each additional cup of coffee consumed per day. Even drinking just one cup daily showed a significant reduction in risk. In a separate study of 86,000 women, those who drank two or more cups daily had a 50% lower risk of suicide compared to non-coffee drinkers.
Coffee, Brain Power, and Aging
A study of 676 healthy men born between 1900 and 1920 found that coffee can help slow cognitive decline associated with aging. Over 10 years, men who drank coffee regularly had an average decline of 1.2 points on the Mini-Mental State Examination, while non-drinkers saw a 2.6-point decline. Men who consumed three cups daily had only a 0.6-point decline.
Even in animal studies, caffeine appears to benefit brain health. Mice with Alzheimer’s showed improved memory and cognitive function after receiving caffeine, suggesting a potential reversal of age-related cognitive decline.
Coffee and Risks: Considerations
Childbearing and Caffeine
Two studies found that consuming around 300 mg of caffeine (roughly two to three cups) can reduce a woman’s chances of pregnancy by over 30% and increase the likelihood of low birth-weight babies by 50%. These studies accounted for factors like contraception use and infertility history.
Hip Fractures and Coffee Consumption
The Nurses’ Health Study found that women aged 65+ who drank more than four cups of coffee daily experienced nearly three times the rate of hip fractures over six years compared to non-coffee drinkers. The study adjusted for factors like calcium intake.
Parkinson’s Disease in Post-Menopausal Women
Research from the Nurses’ Health Study showed differing effects of coffee on Parkinson’s disease risk based on hormone therapy use. Women not on estrogen therapy had a reduced risk of Parkinson’s by 50% with four or more cups of coffee daily. However, for women using post-menopausal estrogen, drinking coffee appeared to double the risk of developing Parkinson’s disease.
Coffee and Heart Disease Risk
Two meta-analyses have shown that people who drank five or more cups of coffee daily were 40-60% more likely to develop heart disease compared to non-coffee drinkers. While high consumption (five to ten cups daily) increases heart disease risk, moderate coffee intake (three to four cups daily) does not seem to be linked to a higher risk.
Interestingly, coffee drinkers consuming more than nine cups a day had an elevated risk of dying from heart disease. However, it’s important to consider that individuals who consume this much coffee may also face other health challenges, such as stress or sleep deprivation, which could further contribute to heart disease risk.
Frequently Asked Question
Does coffee help prevent diseases?
Yes, numerous studies suggest that moderate coffee consumption may reduce the risk of various conditions, including type 2 diabetes, Parkinson’s disease, and certain types of cancer, such as liver and colorectal cancer.
Can coffee improve brain function?
Research shows that coffee can enhance cognitive function and may slow age-related cognitive decline. Studies in both humans and animals have shown that caffeine can help maintain memory and mental sharpness.
How many cups of coffee per day are safe?
For most people, 3-4 cups per day are considered safe and may provide health benefits. However, drinking more than 9 cups a day can increase the risk of heart disease and other health issues.
Are there risks to drinking too much coffee?
Yes, excessive coffee consumption (more than 9 cups a day) can increase the risk of heart disease, sleep disturbances, and other health problems. It’s important to consume coffee in moderation and be mindful of personal health conditions.
Does coffee affect pregnancy?
Drinking more than two to three cups of coffee daily during pregnancy may reduce fertility and increase the chances of having a low birth-weight baby. It’s advised for pregnant women to limit their caffeine intake.
Conclusion
While coffee has long been scrutinized for its potential health risks, recent research highlights its impressive health benefits when consumed in moderation. Studies suggest that coffee can help prevent diseases such as type 2 diabetes, Parkinson’s, and certain cancers, and even boost cognitive function. However, it’s important to note that excessive consumption—especially more than 9 cups per day—can pose risks such as heart disease and sleep disruption.
