Is coffee healthy or unhealthy?
For most healthy adults, three to four cups of filter coffee per day, without sugar and cream, does more good than harm. Pregnant women are a clear exception: limit intake and discuss it with your doctor.
Coffee drinkers live longer on average than people who do not drink coffee. Three to four cups a day is associated with a noticeably lower risk of dying, and this pattern has been found in multiple large studies. That coffee is the cause has not been proven: people who drink coffee may also live more healthily in other ways. Even so, the association is one of the most consistent findings in this field of research.
The picture is stronger for type 2 diabetes. The more coffee a person drinks, the lower the risk of diabetes, and that holds for both regular and decaffeinated coffee. Further research that is better able to distinguish cause from effect points in the same direction. For the liver too, drinking coffee has repeatedly shown benefits: less fatty liver disease and less liver cirrhosis among regular drinkers. High coffee consumption is also associated with an approximately 18% lower risk of cancer in general, with liver cancer and uterine cancer standing out most strongly. For Parkinson's and Alzheimer's there is likewise a consistent pattern in the data, though that does not prove causation.
Preparation matters. Unfiltered coffee, such as boiled coffee or coffee from a French press, contains fatty compounds that raise LDL cholesterol. Filter coffee traps those compounds. This is a risk tied specifically to the preparation method, not to coffee as such.
There are also clear risks. High coffee consumption during pregnancy is associated with a 31% higher chance of low birth weight and a 46% higher chance of pregnancy loss. The recommendation is to limit caffeine intake to a maximum of 200 mg per day, roughly one to two cups; discuss this with your midwife or doctor. Too much coffee can also cause anxiety, sleep problems and heart palpitations in anyone. The threshold at which caffeine causes problems is around 400 mg per day for most people, but sensitivity varies considerably. Women with an elevated risk of bone loss should be aware that coffee is associated in women with a slightly higher risk of bone fractures, although this association has not been found in men. Moderate coffee consumption does not raise blood pressure in the long term, even though blood pressure rises briefly after drinking.
Coffee without sugar and cream appears to be most beneficial. There are indications that adding sugar and cream reduces the positive effects, although that evidence is still limited.
This answer draws on multiple large summaries of dozens of studies, including research that followed people for many years and analyses that make a greater effort to distinguish cause from effect. The findings on total mortality, diabetes and liver conditions are broadly supported and consistent. The cancer and brain findings are likewise consistent, but stem largely from research that measures association only. The risks during pregnancy and of unfiltered coffee on cholesterol are judged to be probably causal. The evidence on bone fractures in women and on adding sugar and cream to coffee is thinner.
Does coffee help protect against type 2 diabetes?
People who habitually drink three to five cups of coffee a day are consistently less likely to develop type 2 diabetes in large population studies, and genetically informed analyses make a causal relationship plausible. Filtered coffee without sugar is preferable, and intake should remain below 400 mg of caffeine per day.
Is soy healthy, or not because of the phytoestrogens?
Soy is probably harmless and possibly beneficial for most healthy adults, but caution is advised for children with thyroid problems. Anyone who eats a lot of soy and has doubts is best off discussing this briefly with a doctor or dietitian.
Can you drink coffee during intermittent fasting?
Black coffee fits comfortably within intermittent fasting and is explicitly listed as a fasting drink in dietary guidelines. If you add a significant amount of milk or sugar, you break the fasting window.
Are smoothies and fresh juice just as healthy as whole fruit?
Whole fruit beats fruit juice: more fibre, greater satiety and fewer free sugars. Smoothies fall somewhere in between, but are not equivalent to whole fruit either.
Is eating organic really healthier?
Eating organic probably does not give you better nutritional value, but it does lower your exposure to pesticide residues and to antibiotic-resistant bacteria through meat. For pregnant women and young children, that is the strongest concrete argument.
Is fibermaxxing (eating as much fibre as possible) healthy?
Eating more fibre is well supported as healthy for most people, but overdoing it causes gastrointestinal complaints and no additional benefit has been demonstrated. Aim for 25 to 29 grams per day through regular food intake.