10 benefits of coffee (and its side effects)

Ten coffee benefits follow, and the first five are the review's headline findings. The BMJ published its umbrella review in 2017, combining 201 meta-analyses from observational studies with 17 interventional ones, and its verdict was that the drink showed benefit more often than harm.

1. Lower risk of death from any cause. Risk reductions were at their clearest for three to four daily cups set against none, where all-cause mortality carried a relative risk of 0.83.

2. Lower cardiovascular mortality. That same three-to-four-cup span showed 0.81 as the relative risk for cardiovascular death.

3. Lower cardiovascular disease risk. Cardiovascular disease itself came in at a relative risk of 0.85, once more comparing three to four daily cups with none.

4. Lower risk of incident cancer. That number uses a second comparison: high consumption against low showed incident cancer at a relative risk of 0.82, an 18 percent lower risk.

5. Lower risk of particular cancers, and of neurological, metabolic and liver conditions. The review lists these as further favourable associations. Every figure above comes from observational work, so it marks association, not cause.

6. A plain cup is nearly energy-free. The 353 kcal per 100 g figure describes dry instant coffee powder, not the drink; a brewed cup is mostly water, and a level teaspoon (5 g) of the dry powder is about 18 kcal before brewing. The energy a cup actually carries arrives with the milk and sugar.

7. Potassium and magnesium stand out. Dry coffee carries 3540 mg potassium and 327 mg magnesium per 100 g.

8. Iron and calcium follow. The same 100 g carries 4.41 mg iron and 141 mg calcium; a teaspoon's worth delivers only a small share, so coffee is a modest contributor, not a main one.

9. Sodium is low. 37 mg per 100 g of dry powder, which barely registers in a mostly-water cup.

10. The bean's benefit is freshness. Coffee beans benefits come down to freshness, because the nutrition figures above are for dry coffee powder and no separate figures are printed for whole beans. Whole beans hold their aroma up to the moment of grinding; COWBERRY seals its Coorg, Karnataka Arabica beans right after the roast to hold that freshness in, ready to be ground only as needed.

The powder from the same roast is ground right after roasting, fine enough for a French press, moka pot, drip or pour-over, and it contains no chicory, preservatives or additives. The coffee powder vs beans page compares the two forms in full.

The same pages that record the benefits also record the limits, and these are real.

Blood pressure and heartbeat. India's dietary guidelines record that coffee drunk to excess is known to push blood pressure up and disturb the heartbeat, and they ask for moderation so the day's caffeine holds within the tolerable limit of 300 mg.

Iron absorption. The same guidelines add that the tannin in tea and coffee can get in the way of iron absorption, which is why they suggest keeping an hour's gap between the drinks and meals, on either side.

Pregnancy. For pregnancy the NHS puts the ceiling at 200 mg of caffeine a day, and it links too much caffeine to a raised chance of miscarriage and stillbirth. In the BMJ review, high versus low or no coffee drinking during pregnancy was associated with low birth weight (odds ratio 1.31), preterm birth in the first and second trimester (1.22 and 1.12) and pregnancy loss (1.46). Follow the 200 mg figure; the coffee in pregnancy page works through the whole day's arithmetic.

Fractures. The BMJ review also reported an association between coffee drinking and fracture risk in women, though not in men.

Children. A 2017 caffeine safety review, working from limited data, keeps 2.5 mg of caffeine per kilogram of body weight a day as its level for children and adolescents; it marks a study benchmark, not a serving suggestion. The coffee for babies page explains what that means by age and weight.

Three numbers matter here, each for a different audience. India's guidelines set the tolerable ceiling at 300 mg of caffeine per day. A 2017 caffeine safety review found that in healthy adults, up to 400 mg a day was generally free of the adverse effects it studied, across heart, behaviour, reproduction and bone; it covered healthy populations only, and it names people with preexisting conditions as a group that could face greater risk. The NHS figure for pregnancy stays at 200 mg a day.

In mugs, the NHS counts roughly 100 mg of caffeine in a mug of instant coffee, so four mugs make 400 mg, three mugs make the 300 mg tolerable limit and two mugs make the 200 mg pregnancy limit; filter coffee can run higher than instant, which shrinks every count. A 150 ml brewed cup in the Indian guidelines runs 80-120 mg and instant coffee 50-65 mg. The coffee calories per 100g page carries the per-cup caffeine numbers in one place.

The pattern behind the evidence is a plain cup, a modest number of them, and nothing added that carries energy you are not counting. Black coffee, or coffee with a small measured milk, keeps the cup's own energy near zero; sugar is what moves it away. Everyday brewing methods sit on the coffee how to make page, and the South Indian cup, milk ratio included, is on the filter coffee how to make page.

On the two big questions, coffee for weight loss tallies what a cup costs and coffee for diabetes lays out the plain-cup baseline for blood sugar. The same material, in everyday Hinglish, is on the coffee ke fayde page, and the coffee hub collects the whole story.

Is coffee good for health?

On balance the evidence leans that way. The 2017 BMJ umbrella review concluded that coffee is more likely to benefit health than harm, with its clearest risk reductions at three to four cups a day; most of the underlying studies are observational, so they show association, not cause. Pregnancy is the main exception, where higher intake was tied to poorer birth outcomes.

Is filter coffee good for health?

The BMJ review reads coffee as one drink across its findings, so the filter cup carries the same evidence, and that evidence leans positive: the 2017 BMJ umbrella review tied coffee drinking to benefit more often than harm, strongest at three to four cups a day. The NHS notes that filter coffee can hold more caffeine than the 100 mg in a mug of instant.

Which coffee is best for health?

The big studies pool every way of brewing together, so in the published evidence no form of coffee has a health edge over the others. What differs between filter, instant and pressed coffee is caffeine per mug and taste. Pick the one you enjoy and keep the cups moderate, at three to four a day where the review's risk reductions were greatest.

Can coffee cause constipation?

The published findings on this page cover mortality, cancer and metabolic outcomes, not digestion, so they carry no answer on constipation either way. A brewed cup is mostly water, which is why the dry-powder figures overstate what a mug holds. For a constipation that will not settle, your doctor is the person to ask.

Does coffee raise blood pressure?

India's dietary guidelines record that heavy coffee drinking is known to raise blood pressure and disrupt the heartbeat, which is why they ask for moderation, with a tolerable limit of 300 mg of caffeine a day. If your blood pressure runs high, your doctor is the person to ask about your own cup.

How many cups of coffee a day is safe?

Three figures answer this: the Indian guidelines set a tolerable limit of 300 mg of caffeine a day, a 2017 review saw up to 400 mg a day in healthy adults with the adverse effects it examined generally absent, and the NHS caps pregnancy at 200 mg a day. At about 100 mg a mug of instant, that is three mugs, four mugs and two mugs.