What Are the Health Effects and Drawbacks of Coffee?

Moderate coffee drinking is linked in epidemiological research to lower rates of cardiovascular disease, type 2 diabetes and liver disease, plus support for metabolism and fat burning. Coffee beans carry plant antioxidants at levels exceeding cocoa, green tea and black tea, and coffee is a leading antioxidant source in many adult diets.

The article also weighs the drawbacks of coffee, including side effects and contraindications, and addresses questions such as consumption during pregnancy. It notes that coffee was long viewed as highly stimulating and potentially addictive, so the balance of benefit and risk depends on how much is consumed and by whom.

As a globally popular beverage, coffee not only boosts alertness, but in recent years more and more research has confirmed that moderate consumption has positive effects on health. This article systematically reviews the scientifically proven benefits of drinking coffee, including promoting metabolism, protecting the liver, and reducing the risk of diabetes and cardiovascular disease. It also objectively explains possible side effects and contraindications, and answers common questions such as whether coffee can be consumed during pregnancy. The article also recommends related products from Front Street Coffee for coffee lovers' reference.

Since coffee was discovered thousands of years ago, it has taken the world by storm with its unique flavor and alertness-boosting effects, making it one of the most flavorful and health-promoting beverages in the world, once even hailed as the "drink of the gods."

Coffee beans are rich in plant antioxidants, with antioxidant capacity even exceeding that of cocoa, green tea, and black tea. A study in a nutrition journal further pointed out that coffee is actually the largest source of antioxidants in the adult diet, a conclusion that surprised many people.

When it comes to drinking coffee, most people first think only of its alertness-boosting effect, and in the past it was often considered highly stimulating and easily addictive, making people both love it and worry about it.

However, multiple epidemiological observations have confirmed that moderate coffee consumption is indeed beneficial to health and can reduce the incidence of many diseases, such as cerebrovascular and cardiovascular diseases, diabetes, and liver disease.

What are the benefits of drinking coffee

Scientifically proven benefits of drinking coffee What are they

1. Promotes metabolism, helps burn fat, and aids weight loss

In the past, people worried about not having enough to eat and being skin and bones. Now, with changed lifestyles and overly refined diets, obesity rates remain high, and the overweight population has almost surpassed the slim population.

Weight loss is a process most people (especially women) have experienced, but they often lack clear direction. Due to different physiological structures, women bear the important responsibility of reproduction, so they are more prone to storing fat, which helps maintain body temperature and provide energy, making it harder for them than men to maintain a standard weight.

Several studies have found that caffeine in coffee can affect energy balance and increase thermogenesis, helping to raise the metabolic rate by 3-11%.

Another study found that caffeine helps dieters maintain weight. The mechanism is related to coffee's ability to increase energy expenditure and reduce calorie intake, and it may have an appetite-suppressing effect. If coffee consumption is combined with exercise, the fat-burning and weight-loss effect is better than exercise alone.

A weight-loss health food that reduces body fat

2. Reduces the risk of liver cancer

Liver cancer is a common cancer of the digestive tract organs, ranking 5th and 8th among cancers in men and women respectively, with hepatocellular carcinoma being the most common.

Among the causes of hepatocellular carcinoma, 70% to 90% of patients have a history of chronic liver disease or cirrhosis. The main risk factors include viral hepatitis, alcoholic liver disease, or non-alcoholic fatty liver disease, as well as obesity, diabetes, hereditary diseases, and foods contaminated with aflatoxin.

A meta-analysis pointed out that subjects with a habit of drinking coffee can reduce the risk of hepatocellular carcinoma by an average of about 40%.

The same study also found that coffee's liver-protective effect remained consistent across different ethnic groups or subgroups, such as by sex, alcohol abuse, or history of hepatitis or liver disease.

Another meta-analysis on dose-response analysis also pointed out that drinking 1 cup of coffee per day can reduce the risk of liver cancer by 15%, but there is no obvious association with the risk of biliary tract cancer.

Conclusion: Population observational studies have found that people with a habit of drinking coffee have a lower risk of liver cancer.

3. Dementia (Alzheimer's disease)

Dementia is one of the diseases older adults fear most, and Alzheimer's disease is the most common, accounting for 70% of all cases, with prevalence increasing from 1% after age 60 to a higher proportion by age 90.

Alzheimer's disease is a neurodegenerative disease. Early symptoms include loss of memory and sense of direction, impaired judgment and decision-making, and language impairment. In the middle and later stages, various psychiatric symptoms may even appear, such as depression, apathy, anxiety, agitation, delusions, and hallucinations, bringing difficulties in caregiving to patients' families.

A meta-analysis (including 11 prospective studies with a sample size of 29,115 people) pointed out that although drinking coffee cannot significantly improve cognitive decline and dementia indices, subgroup analysis found it helps reduce the risk of Alzheimer's disease by 27% (highest intake compared with lowest intake).

The mechanism behind this is believed to be related to components in coffee having an adenosine receptor antagonist effect, thereby slowing nervous system damage caused by the accumulation of beta-amyloid plaques, but more verification is still needed to further confirm this.

4. Coffee and non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease is an ectopic fat disease and the most common liver disease in Western countries, affecting about one in three people. Patients are usually asymptomatic, but reported non-specific symptoms include fatigue and discomfort in the right upper abdomen.

Fatty liver refers to abnormal accumulation of fat in liver cells (obesity and diabetes are the main causes). Depending on severity, disease progression from mild to severe can be divided into steatosis, steatohepatitis, fibrosis, and even cirrhosis. The most serious complication is hepatocellular carcinoma.

A systematic review and meta-analysis (including 5 studies) pointed out that people with a regular coffee-drinking habit can help reduce the incidence of non-alcoholic fatty liver disease by 29%. In addition, for subjects already suffering from non-alcoholic fatty liver disease, drinking coffee can reduce the risk of progression to liver fibrosis by 30%.

5. Reduces the incidence of type 2 diabetes

Diabetes is one of the fastest-growing diseases worldwide, caused by obesity, lack of exercise, and poor dietary habits. According to World Health Organization statistics, 9% of the world's population over 18 has diabetes. If blood sugar remains uncontrolled for a long time, it can cause difficult-to-reverse symptoms such as blindness, amputation, and kidney failure.

Multiple studies have found an inverse relationship between coffee drinking and the incidence of diabetes. Heavy consumers have a much lower incidence rate than non-consumers, and each cup of coffee can reduce the relative risk by about an additional 7%.

A large systematic review (including 193,000 men and women) pointed out that people who drink 6 cups of coffee per day can reduce the risk of diabetes by 35%, while those who drink 4-6 cups reduce it by 28% (compared with those who drink fewer than 2 cups).

Another cohort study (including 41,934 men and 84,276 women) also observed that if more than 6 cups of coffee are consumed daily, men and women can reduce the incidence of type 2 diabetes by 54% and 29% respectively (compared with non-drinkers).

The mechanism behind this is believed to be related to chlorogenic acid and trigonelline in coffee beans. Both substances have been found to lower blood sugar and improve insulin concentration (as found in oral glucose tolerance tests).

6. Reduces the incidence of cardiovascular disease

Cardiovascular disease is a health killer second only to cancer, especially for older adults, and is characterized by high incidence, high mortality, and high disability rates.

Clinically, it has also been found that about 80% of cardiovascular diseases originate from arteriosclerosis and vascular obstruction. This not only makes coronary heart disease more likely, but also makes complications such as heart failure, stroke, and claudication (lower limb vascular obstruction) more likely.

Early on, several studies suggested that drinking coffee might increase the risk of coronary heart disease, but after years of verification, it has been confirmed that moderate coffee drinking is still beneficial to cardiovascular health.

In a large Finnish observational study (including 59,490 people with an observation period of 19.2 years), it was found that women who consumed 1 to 2 cups of coffee per day could reduce the risk of heart failure by 27% (compared with non-drinkers).

Another large observational study targeting diabetic patients also found that drinking coffee helps reduce all-cause mortality and the risk of death from cardiovascular disease by 30%.

7. Reduces the incidence of stroke

Stroke is mainly divided into hemorrhagic and ischemic vascular lesions. Because the brain is one of the body's most oxygen-consuming organs (10 times that of the heart), once cerebral blood vessels become blocked or bleed while transporting oxygen or energy, nerve cells are prone to damage. If cerebral arterial blood flow is interrupted for less than 30 seconds, damaged cells may still recover; if interrupted for more than 5 minutes or even several hours, nerve cells are almost completely destroyed, so maintaining normal cerebral vascular function is very important.

One observation found that coffee drinkers may help reduce the chance of cerebral hemorrhage by 36%.

Other observations also found that people who drink 3-4 cups of coffee per day can reduce the chance of dying from stroke by 23% (compared with those who drink fewer than 2 cups), while those who drink 5 to 6 cups have a reduction as high as 36%.

8. Improves athletic performance

Whether you are a professional athlete or an ordinary person who only exercises occasionally, improving athletic performance through various scientific methods not only gives a greater sense of achievement but also increases motivation to keep going.

Studies have found that caffeine can increase epinephrine in the blood. Epinephrine is a hormone usually secreted in large amounts during fight-or-flight responses, enabling the body to cope with large physical exertion.

In addition, caffeine can also promote fat cells to release fatty acids into the blood for use as energy.

Combining these two effects, a meta-analysis of exercise tests mentioned that caffeine can improve athletic performance, with an average score increase of 12.3%, especially in endurance sports.

What are the side effects of drinking coffee? (Drawbacks)

Most coffee-related side effects are related to excessive caffeine intake in the short term. Common adverse reactions include palpitations, rapid heartbeat, insomnia, anxiety, restlessness, tremors, headache, abdominal pain, nausea, vomiting, diarrhea, and frequent urination. Abnormally high doses of caffeine may also lead to hypokalemia.

For long-term coffee drinkers, if they suddenly stop or reduce the number of cups, caffeine withdrawal may occur. Common symptoms include headache, fatigue, irritability, difficulty concentrating, and low mood.

Drinking coffee may increase blood pressure by 3-4 mm/Hg. For people with a habit of drinking coffee, these effects gradually disappear.

However, some studies also point out that tolerance does not develop completely, especially for certain groups (such as people with hypertension, those who are overweight, and older adults), who may have a stronger blood-pressure-increasing effect, so care should be taken to avoid excessive caffeine intake.

Safety precautions (contraindications)

Some drugs interfere with the liver's metabolism of caffeine and may increase caffeine-related side effects (such as gastric acid suppressants/Tagamet, anti-addiction agents/Antabuseestrogens, antifungals/Diflucan, antipsychotics/Luvox, antiarrhythmics/Mexitil, antifungals/Lamisil).

For people with insufficient calcium intake, consuming coffee (more than 4 cups, containing about 330 mg of caffeine) may increase the risk of osteoporosis.

Excessive caffeine intake during pregnancy (more than 300 mg per day) may increase the risk of miscarriage and lower fetal weight, but to date the related results remain inconsistent. To be cautious, it is best to reduce intake during pregnancy (do not exceed one cup).

Front Street Coffee recommendation: If you want to try coffee that is beneficial to health, you can choose Front Street Coffee's beans. The quality is stable, the flavor is balanced, and it is suitable for daily drinking.

The above content is compiled by CoffeeHunters, a coffee news website.