Coffee wars: What scientists have to say about the age-old debate over coffee and its impact on health

A fair number of scientists have pronounced coffee good for health and an equal number have pointed out its adverse effects on the heart and brain health.

Myupchar August 20, 2019 15:57:16 IST
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Coffee wars: What scientists have to say about the age-old debate over coffee and its impact on health
  • A fair number of scientists have pronounced coffee good for health and an equal number have pointed out its adverse effects

  • In June 2016, the World Health Organization (WHO) officially removed coffee from its list of carcinogenic (cancer-causing) foods

  • WHO categorised coffee as potentially protective against cancer of the uterus and liver

Early mornings are always stressful. You’ve got back-to-back meetings to set the pace for the rest of the day. Chances are, you’ll go through two or three cups of coffee by lunch. But is that much coffee really good for you and your productivity?

In August, a new study in the American Journal of Medicine (AJM) reopened the coffee-is-good versus coffee-is-bad for health debate.

Coffee wars What scientists have to say about the ageold debate over coffee and its impact on health

Representational Image: Photo courtesy: Wikimedia Commons

The AJM study found that drinking three or more caffeinated drinks (many energy drinks also have caffeine) in a day can trigger a migraine attack — either on the same day or the following day — in people who experience episodic migraine. Migraine affects 1.04 billion people worldwide, and women are twice as likely to get it compared to men. Episodic migraine, as opposed to chronic migraine, is characterised by a person getting migraines anywhere between zero to 14 days in a month.

However, in the past, coffee has also been shown to reduce the risk of migraine.

“Sure, studies can sometimes contradict each other,” said Dr Archana Nirula, a medical practitioner associated with myUpchar.com. “But that’s how science works - by constantly proving and disproving theories, arguing and counter-arguing. These are all steps in the right direction,” she added.

Getting back to the coffee-is-good theory, research has also shown that coffee can make a headache go away - coffee constricts the blood vessels and reduces swelling. Remedies like aspirin, ibuprofen or acetaminophen work better when combined with caffeine.

Coffee also contains chlorogenic acid, a known antioxidant that can help improve the metabolism and aid in weight loss. Coffee is said to be beneficial for the heart, kidneys, brain and overall energy levels. The downside is that you can have too much of a good thing - drinking too much coffee can impair sleep, increase blood pressure and cause non-cancerous lumps in the breasts (fibrocystic breast disease). Plus, drinking coffee with sugar robs the coffee of some of its benefits.

But wait, there’s more.

Coffee wars

Scientists have been studying coffee for many decades. A fair number have pronounced it unequivocally good, and an equal number have pointed out its adverse effects on the heart and brain health.

In 2011, Masooq Sadiq Butt and M. Tauseef Sultan argued in the Critical Reviews in Food Science and Nutrition that coffee helps in proper cognitive function.

In 2014, Elvira Gonzales de Mejia and Marco Vinicio Ramirez-Mares wrote in Trends in Endocrinology & Metabolism — a peer-reviewed journal published by the well-regarded CellPress — that the caffeine in coffee is a “bioactive compound with stimulatory effects on the central nervous system and a positive effect on long-term memory.”

More recently, in March 2019, scientists argued in the American Journal of Critical Nutrition that coffee boosts the metabolism and has a “favourable” impact on inflammatory pathways.

However, on the other side of the fence are eminent scientists who argue that caffeine intake can increase the chances of atrial fibrillation - abnormal heart rhythm, cancers like non-melanoma skin cancer, and even auto-immune conditions like rheumatoid arthritis.

WHO says

Can coffee prevent cancer? Some researchers certainly seem to think so.

In 2015, the World Cancer Research Fund International linked coffee consumption with a lower risk of several types of cancer. According to a study published in the Journal of the National Cancer Institute, coffee reduces the risk of melanoma, a type of skin cancer. The researchers closely observed the coffee-drinking habits of more than 447,000 people in the U.S. over 10 years and concluded that those who drank four or more cups of coffee each day had a 20% lower risk of developing melanoma.

In June 2016, the World Health Organization (WHO) officially removed coffee from its list of carcinogenic (cancer-causing) foods. Instead, WHO categorised coffee as potentially protective against cancer of the uterus and liver.

An analysis of nearly 220 studies on coffee, published in the peer-reviewed British Medical Journal in 2017, stated that coffee drinkers were 17% less likely to die early from any cause, 19% less likely to die of heart disease and 18% less likely to develop cancer than those who don't drink coffee.

Black, no sugar

The local coffee plantations and roasteries scene are now blooming across the country: never before have we had so much choice in terms of berries, blends and brewing methods. As fresh grinds and flavours become more widely available, more people are starting to favour black coffee without sugar and sugar supplements. In short, we are starting to drink the kind of coffee included in Western studies on the relationship between coffee and cancer and coffee and diabetes.

India is the diabetes capital of the world - the number of people living with diabetes had crossed 70 million in 2017. It’s a long-shot, but going by this new trend in coffee consumption, there's reason to hope that things might yet improve.

As early as 2002, a study published in The Lancet said that drinking coffee reduces sensitivity to insulin: the sugar-regulating hormone in the body.

Then, in 2005, the American Heart Association’s journal, JAMA, published a systematic review based on nine cohort — or cross-sectional — studies with nearly 200,000 participants. That review, too, confirmed the benefits of black coffee for diabetics.

In 2014, researchers at the Harvard Medical School published a study in the journal Diabetologica - they had studied nearly 124,000 people for 16–20 years, and found that those who enjoyed more than a cup of coffee a day were at 11% lower risk of developing Type 2 diabetes. While those who decreased their intake by one cup per day were at a 17% higher risk of developing the disease.

In their 2019 book Coffee: Consumption and Health Implications, authors Heidi Virtanen, Rogerio Nogueira Soares and Jane Shearer that drinking six shots of coffee a day can reduce the risk for type 2 diabetes by a massive 33 percentage points.

It’s rare for scientists to agree so whole-heartedly on something across locations and time periods. Yet, here we have it: black coffee can help manage diabetes.

Coffee and Parkinson’s?

Coffee is known to improve cognitive function. Most of us know this from experience.

In 2012, a research study showed it could even help reduce the symptoms of Parkinson’s - a degenerative disease in which the brain stops producing adequate dopamine to maintain regular muscle function. In an article in the Journal of the American Academy of Neurology, the researchers argued that a daily dose of two eight-ounce cups of black coffee or their caffeine equivalent can help to control the involuntary movements of Parkinson’s patients. This has since been supported by many other studies.

The heart is set on coffee

In 2013, the journal Epidemiology and Prevention published a review of studies analysing the correlation between coffee consumption and cardiovascular disease. Data from 36 different studies showed that people who drink three to five cups of coffee per day have a lower risk of heart disease than those who drink no coffee or more than five cups per day.

Although there are many studies to support the theory that coffee has more benefits than risks, we have yet to fully understand how it works in different individuals. So if you are someone who feels their heart flutter every time they have a cuppa, or you have a migraine, it’s best to talk to your doctor before you come over to the dark (brew) side and commit to the caffeinated life.

For the rest of us who swear by coffee to clear the mind, science says we’ve been doing the right thing all along.

Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health. To know more on this topic, please visit https://www.myupchar.com/en/tips/coffee-ke-fayde-aur-nuksan-in-hindi

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