Is green tea really as healthy as they say?
Two to three cups of green tea a day fits well into a healthy lifestyle and is probably safe, but do not take concentrated green tea extracts as a supplement: they can damage your liver.
Green tea is probably good for your heart, but the claims go further than the evidence supports. Drinking two to three cups a day (roughly 500 mL) may improve the flexibility of your blood vessels, although the most important research on this comes from employees of tea manufacturer Unilever. Large population studies also show an association between regular tea drinking and lower rates of cardiovascular disease: people who drink five or six cups a day tend to score better on blood pressure and blood sugar on average. These are associations, not proof that tea itself is the cause. If you want to try it for your heart, choose ordinary green or black tea as a drink; look for 'green tea' or 'black tea' on the label.
For concentration and attention, you may want to try L-theanine at 200 to 250 mg per day, ideally combined with caffeine as found in green tea or matcha. An acute effect is possible; for a longer-lasting result, stick with it for at least 12 weeks. On the label, look for 'L-theanine' or 'matcha'. Whether you take L-theanine alone or with caffeine makes a difference: the combination works better than either on its own.
For weight management, muscle building, gut health and cancer prevention, the evidence is too thin to support a recommendation. Evidence for neuroprotection in humans is also lacking. Wait for stronger studies in these areas.
A crucial safety point: drinking ordinary green tea is probably safe. Concentrated green tea extracts in capsule form, labelled 'green tea extract' or 'EGCG', are a different matter. Research points to a real risk of liver damage and possibly DNA damage at high doses. Do not take tea extract supplements without consulting your doctor. Green tea as a drink does not carry that risk.
All sources are reviews; no randomised trials or meta-analyses were directly provided as a source. The association with cardiovascular disease rests largely on population research without random assignment.
How healthy is olive oil and what is it good for?
Olive oil, and extra-virgin olive oil in particular, is well supported as protective for the heart and blood vessels, especially when used in place of butter and as part of a varied, plant-based diet.
Is coffee good or bad for your heart?
For most healthy adults, three to four filtered cups per day is associated with a beneficial effect on the heart and blood vessels. Pregnant women are an important exception: for them, the maximum is around two cups per day.
How bad is eating a lot of salt for me?
Eating a lot of salt is clearly harmful to your blood pressure and your heart, and the risk grows with the amount consumed. Eating more vegetables and fruit helps to temper the effect, but does not replace reducing salt intake.
Does coffee lower the risk of premature death?
Coffee (3 to 4 cups per day, preferably in the morning and without much sugar) is associated with less early death in large population studies, but this is an association, not a proven cause. Pregnant women are a clear exception.
Is the taurine in energy drinks harmful?
Taurine in energy drinks does not appear to be harmful in the short term, but the real risks lie in the caffeine and sugar. If you want a reason to avoid energy drinks, that is the right one.
Does taking omega-3 help you stay healthy for longer?
Omega-3 reliably lowers blood fats, but the evidence that it helps you live longer or stay healthier is limited. If you already have heart disease, discuss with your doctor whether omega-3 is a worthwhile addition to your treatment.