Coffee

Coffee

Coffee (Coffea arabica, Coffea robusta; in Hebrew “קפה”) is the most consumed hot drink in the world, and one of the most studied foods in the history of nutrition science. With thousands of studies published in recent decades, the picture that emerges is complex — coffee has both significant health benefits and risks that depend on the amount, the type and the individual response.

Coffee beans contain hundreds of compounds — caffeine, chlorogenic acids, diterpenes (cafestol and kahweol), trigonelline and more — that work together to create a complex bioactive profile.

Research-based health benefits

• A leading source of antioxidants in the Western diet: dietary studies in the US and Europe found that coffee (not fruits or vegetables) is the largest source of antioxidants in the average diet — because of the large amount consumed. Chlorogenic acids are the main polyphenols, with anti-inflammatory activity and glucose regulation.

• Cognitive performance and alertness: caffeine blocks adenosine receptors in the brain — the main mechanism that creates sleepiness. The result: improved concentration, reaction time, alertness and mood. A noticeable effect at 100-200 mg of caffeine (1-2 cups).

• Physical performance: caffeine is recognized and approved as an ergogenic aid (a sports performance enhancer) by international sports bodies — it increases the release of fat for energy and reduces perceived exertion relative to output.

• Preventing chronic disease (epidemiology): large studies (including PREDIMED and the Nurses’ Health Study) found a link between moderate coffee consumption (3-4 cups a day) and a lower risk of type 2 diabetes, Parkinson’s disease, Alzheimer’s, liver cirrhosis and certain types of cancer.

• Liver function: coffee — even decaf — is linked to a lower risk of liver cirrhosis, liver cancer and elevated liver enzyme levels. Possibly because of chlorogenic acids and other compounds.

• Long-term brain function: regular consumption is linked to a lower risk of Parkinson’s and Alzheimer’s — possibly because of the neuroprotective effect of caffeine and antioxidants.

Downsides and health considerations

• Anxiety and jitteriness: a high dose (over 400 mg of caffeine a day = 4+ cups) causes anxiety, jitteriness, palpitations and sleep disturbances. The sensitivity threshold is individual and influenced by genetics (the CYP1A2 polymorphism).

• Dependence and withdrawal symptoms: caffeine creates a mild physiological dependence. Stopping suddenly causes headaches, fatigue and irritability — usually for 1-3 days.

• Effect on sleep: caffeine has a half-life of 5-6 hours — a cup of coffee at 15:00 is still active at 21:00. For people sensitive to sleep disruption — not recommended after 12:00.

• Blood pressure: a sharp short-term rise in blood pressure after drinking. People with uncontrolled high blood pressure should cut back.

• Iron absorption: coffee (like tea) reduces the absorption of non-heme iron. Don’t drink it close to iron-rich meals.

• Pregnancy: health organizations recommend not exceeding 200 mg of caffeine a day during pregnancy (one cup is the safest).

• Kahweol and cafestol: diterpenes that raise LDL — found in unfiltered coffee (French press, espresso). A paper filter removes them effectively. Drinking paper-filtered coffee is better for your cholesterol profile.

Filtered vs. unfiltered coffee

Summary

Coffee in moderate amounts (3-4 cups a day, black or with a little milk, paper-filtered) is a drink with research-backed health benefits for most of the adult population. Be careful during pregnancy and with sleep problems, blood pressure and caffeine sensitivity.