Studies and research suggest that the physiological effects of drinking coffee can extend beyond a small dose of wakefulness, but only if done in moderation.

Shillpi A Singh

“The powers of a man’s mind are directly proportioned to the quantity of coffee he drinks,” stated Sir James Mackintosh, a caffeinator who believed that coffee helped improve understanding.

Here’s what a fact-check of Mackintosh’s statement reveals about the impact of caffeine on depression, skin health, blood pressure and blood sugar.

Coffee and depression

Ask a caffeinator why they rush for a cup of coffee when they feel a bit low, and pat would come to the response… it gives an immediate boost of energy. Caffeine, the stimulant found in beverages like coffee, is a probable mood-lifter. Perhaps that’s the reason why most people consume coffee with the US alone accounting for over 600 million cups of coffee being guzzled each day.

Research into coffee and depression has found that people tend to experience less severe symptoms when they drink coffee.

A large longitudinal study titled Coffee, Caffeine, and Risk of Depression Among Women, found that depression risk decreases with increasing caffeinated coffee consumption. A meta-analysis with a dose-response analysis quantitatively summarized that coffee and caffeine consumption were significantly associated with decreased risk of depression.

Dr Kriti Anand, Associate Consultant, Psychiatry, Paras Hospitals, Panchkula, states, “Caffeine may be considered as the much-needed accelerator included in medication to help you feel quick relief. The plant-based substance may also help some people deal with the effects of depression.”

Elucidating it further, Dr Anand adds that depression is a mood disorder that affects approximately 1 in 5 Indians in a lifetime, and is often treated using a combination of psychotherapy and medication.

“An analysis of the relationship between caffeine and depression found that caffeine consumption decreased depression risk. Another study found a connection between decreased depression and coffee consumption, but no connection with other caffeinated drinks. These findings suggest that it is something in coffee that reduces the risk for depression, not caffeine,” he claims.

Caffeine may help relieve depressive symptoms or protect against depression suggests Research. A 2016 meta-analysis accounting for 3,46,913 individuals and 8,146 cases of depression suggested that coffee consumption may have a protective effect. A dose-response analysis suggests a J-shaped curve, with the effect reported for up to approx 300 mg of caffeine (about 4 cups of coffee) per day.

However, the risks of drinking too much coffee galore among those looking for energy to push through with their jobs or studies. According to Food and Drug Administration, four regular-sized cups of coffee is considered generally safe. However, drinking coffee can produce side effects such as restlessness, rapid heartbeat and insomnia.

Quoting studies, health experts advise moderation because more than four cups of coffee per day can have an adverse impact on the body. Some people reported heightened anxiety, headaches and agitation on the consumption of more than four cups. The Diagnostic and Statistical Manual of Mental Disorders, which is used to assess and diagnose mental disorders, calls it “coffee intoxication”.

“Caffeine consumption in children and teenagers was found to increase depression among 5th and 10th graders. Caffeine has a negative impact on sleep, and that could affect a person’s mood. The type of caffeinated drink, person’s age and sensitivity to caffeine also have a role to play,” says Dr Anand.

Studies have found positive benefits of coffee on the body such as lowering the risk of getting cancer or stroke, developing dementia and Parkinson’s disease. That’s not all. The effects of caffeine along with the protective compounds found in coffee beans can considerably lower the potential of developing Alzheimer’s disease and improve mental cognitive abilities.

“The powers of a man’s mind are directly proportioned to the quantity of coffee he drinks,” stated Sir James Mackintosh, a caffeinator who believed that coffee helped improve understanding.

Well, we at THIP fact-checked Mackintosh’s statement to find out more about the impact of caffeine on depression, skin health, blood pressure and blood sugar, and this is what we found.

Coffee and diabetes

There is good news for those who can’t face the day till they have downed a cup of coffee. A study by Harvard School of Public Health researchers found that coffee consumption lowered women’s risk of type 2 diabetes by 8%, while for men it was 4% by drinking regular coffee and 7% for decaffeinated coffee.

The 2012 findings made the case that coffee is a healthy drink for most people. But conditions apply, coffee is good as long as it isn’t loaded with cream and sugar.

However, caffeine affects every person differently. If a person already has diabetes, the impact of caffeine on insulin action may be associated with higher or lower blood sugar levels. In other words, coffee could have adverse effects on those who already have type 2 diabetes. Coffee can raise blood sugar and insulin levels for diabetics because caffeine can affect how the body responds to insulin, the hormone that allows sugar to enter the cells and get converted into energy.

Caffeine may lower insulin sensitivity. In other words, the cells don’t react to the hormone as much as they once did or don’t absorb as much sugar from blood after a meal or a drink. It causes the body to make more insulin, so sugar levels are higher than normal after meals. Caffeine may make it tougher for a person with type 2 diabetes to bring down insulin to a healthy point and may lead to too-high blood sugar levels. Over time, this may raise the chance of diabetes complications, like nerve damage or heart disease.

Dr Gaurav Palikhe, Consultant, Endocrinology, Paras Hospitals, Panchkula, agrees that it has been proven from various studies that coffee acutely raises blood glucose due to various mechanisms like antagonism to adenosine receptors in muscle, the release of catecholamines and stimulation of lipolysis. “Though in the long term, it has been shown to prevent diabetes from epidemiological studies. This specific 50% rise in blood glucose was found in a study by UK researchers published in the British Journal of Nutrition in 2020. They found 50% more blood glucose rise following ingestion of black coffee preceding breakfast. Hence, the take-home point from this is that it’s better to take coffee sometime after the completion of breakfast to prevent this rise in postprandial blood rise in blood glucose.”

Coffee and blood pressure

Research indicates that coffee consumption may increase blood pressure for a short time. A review of 34 studies showed that 200-300 mg of caffeine from coffee (approximately 1.5-2 cups) led to an average increase of 8 mm Hg and 6 mm Hg in systolic and diastolic blood pressure, respectively.

The impact was visible for up to three hours after coffee consumption, and results were similar in people with normal blood pressure at baseline and those with pre-existing high blood pressure. However, interestingly, regular coffee consumption is not associated with the same impact on blood pressure — which may be due to the caffeine tolerance that develops when you habitually drink it.

To explain this phenomenon, Dr Smriti Naswa, Consultant Clinical, Pediatric & Cosmetic Dermatologist, Fortis Hospital Mulund, Mumbai, says, “Coffee has caffeine. It can lead to increased heart rate, blood pressure by constricting blood vessels. A good blood supply to the skin ensures toxin removal and rejuvenation of the skin which doesn’t happen with the caffeine effect.”

However, she warns against excess consumption of coffee. “The dehydrating properties of coffee make skin looks dry, lusterless, and also aged (if someone binges on coffee or tea). Moreover, it is also acidic (just like tea) and can enhance ageing,” says Dr Naswa.

So health experts and studies advise that coffee consumption can be good for health, but only if done in moderation.