Coffee Keeps You Awake, But Why and How Do You Think That Is?

While we down mug after mug loaded with caffeine, have you wondered what exactly it is doing to your body?

(Photo: iStockphoto)

In the previous year, the Post Monsoon Crop Estimate for coffee production was placed at 3,19,500 MT in India, according to the Coffee Board of the Indian government. This included both the Arabica as well as the Robusta kinds of coffee. Now, who are we kidding? That’s a LOT of coffee. While a good, old cup of tea remains king in tier-II and III cities, the coffee-craze is fast catching on in urban India.

While we down mug after mug loaded with caffeine, have you wondered what exactly it is doing to your body?

First, Let’s Begin With Understanding Caffeine

Caffeine, found in both tea and coffee, is a natural substance that is extracted from plants and has no nutritional requirement in the diet. An average adult can have about 8 ounce or 240 millilitre or about three cups of coffee every day and it would be considered a moderate amount of caffeine. Anything above this is not recommended, according to this report.

Caffeine is also a type of drug that promotes alertness and falls in the category of stimulants, points out another study.

Manjari Chandra, Consultant Nutritionist, Max Hospital, New Delhi, adds to this and says:

Caffeine acts as a central nervous system stimulant. When it reaches your brain, you feel  more awake and less tired.

When Coffee Enters Your Body

You just gulped down a mug of coffee, what next, you wonder?(Photo: iStockphoto)

You just gulped down a mug of coffee, what next, you wonder? Well, the caffeine in it would get to work within the first 15 minutes and then would take anything between 30-60 minutes to reach its peak, according to this report here.

Caffeine enters the bloodstream through the stomach and the small intestine and then hangs around in the body for about a few hours. It takes around six hours for half of the caffeine to be eliminated. It wards off sleep by blocking the adenosine (substance that makes you sleepy) receptor in the body.

It only takes about 45 minutes for 99 percent of the drink’s caffeine to be absorbed . In humans, the half-life for caffeine is anywhere from four to six hours on average, which explains why the average energy drink or coffee’s effects last about four to six hours.

Manjari Chandra

Studies have further pointed out that coffee can disrupt your sleep and body clock in a significant manner by delaying when you usually feel sleepy, cutting down the hours of deep sleep or simply causing restless sleep. Another study supported this and said that consuming caffeine even six hours before your bedtime can cut down sleep by about an hour.

Coffee or caffeine can upset our circadian rhythms. A cup of coffee an hour before bedtime may reduce effective sleep by an hour.

Manjari Chandra

However how your body responds to caffeine will be different from different people. While some people stay up for hours after a cup of coffee, others can hit the sack immediately without a worry in the world.

For instance, fifty college students in the US were asked to record their caffeine consumption and how it affected their sleep, according to this report. The observations concluded that they were already so exhausted and sleep deprived that they fell asleep anyway irrespective of when they had coffee.

However, in addition to simple sleep deprivation, there are several other factors which determine the effects of coffee on an individual.

Factors That Decide How Caffeine Affects Your Body

The effects of caffeine on your sleep is also determined by how much caffeine you’ve had during the entire day and just before bedtime.(Photo: iStockphoto)

Gender has a role to play. Data suggests that of the people who believe themselves to be dependent on coffee, women have a harder time dealing with its effects on sleep. Additionally, even a single day of abstinence from coffee can help improve sleep hygiene significantly. This was further observed even if people had decaffeinated coffee.

Along with gender, other factors that determine effects of caffeine on your body include age, sensitivity, genetic makeup and time of consumption.

The effects of caffeine on your sleep is also determined by how much caffeine you’ve had during the entire day and just before bedtime, according to this study. While the aforementioned studies mention numbers in terms of hours of sleep which caffeine disrupts, the jury is still out on the extent of these effects.