Scientific Reason for Why You Get Jet Lag

Traveling is a great experience for those who are fortunate enough to set out in the world for a grand adventure. You get to explore unseen horizons, meet new people, and do tons of other things that are great for your brain and your overall wellbeing. However, if you are a frequent traveler and skip between places that are scattered all around the world, then you are eventually going to experience a rather nasty illness that afflicts globe-trotters… Jet Lag!

What is Jet Lag?

Credits: Air Travel/Shutterstock

Jet lag is a condition that is characterized by extreme tiredness and various other physical affects (such as headaches, uneasiness, anxiety etc.) that occur when you travel great distances, usually in an airplane, through different time zones. To understand it better, imagine that you’re traveling from New York to London. Since the time in London is 5 hours ahead of New York, you will feel uneasiness or discomfort for a short time after that travel, because you are essentially re-programming your body to lose or gain time in a given day, which isn’t always easy to do! 

The worst thing about jet lag is that its symptoms may last for a couple of days or even longer, depending on how fast your body adjusts to the time zone of the new place. This can be very annoying if your trip abroad is very short, and you’ll be heading home before you ever feel normal!

Why Do We Suffer from Jet Lag?

Image Source: Wikimedia

Jet lag occurs when the sleep-wake cycle, also referred to as the Circadian rhythm, of an individual is disturbed. The whole process begins in your eyes; there are special pigments in your eyes that transmit natural light to the designated sections of your brain. These signals are received by a cluster of about 20,000 neurons in a tiny area of the hypothalamus. The Suprachiasmatic nucleus (SCN) is situated in this cluster, which is responsible for sensing natural light and subsequently sending signals to other parts of the brain.

When the SCN senses a lot of natural light, it tells the other sections of the brain to shake off the laziness and start performing their activities at full capacity, because that is when the brain known to be active and awake. In contrast, when the SCN senses less natural light, a hormone called melatonin tells various parts of brain to slow down and get some rest. This is why you tend to feel lazy and drowsy as the bright natural daylight starts to wane.

How Traveling Affects the Sleep Cycle

When you’re traveling fast in an airplane and therefore covering large distances in a short span of time, you are essentially crossing over areas with different time zones.

Credits: faithie/Shutterstock

In other words, when you started your journey from City A, it was dark and approaching your normal time to sleep, but you reached another City B in just 5 hours, where there was still a lot of light and everyone was acting normally, going about doing their daily tasks.

Think about your poor brain in that situation. It will become confused, so your sleep-wake cycle, or circadian rhythm, is badly disturbed.

How Can You Deal with Jet Lag?

Since light is the most important element in the occurrence of jet lag, it significantly helps if you can take care of this factor. As a general rule, it’s easier to adjust to the new time zone for east-to-west travel than it is for west-to-east travel, as there is not a significant difference in the intensity of natural light.

Other remedies include strict and timed light exposure to match the circadian rhythms with the expected cycle at the destination, timed melatonin administration, and even making an adjustment to the timing of having meals and performing exercise.

Although you may not realize it, the sleep-wake cycle is a very important factor for maintaining good health – and sanity! Therefore, next time you alight at your destination airport and feel mysteriously irritable, exhausted, and slightly confused as to what world you’ve just landed in, just remember that jet lag has worked its evil magic on you, and hope that the effects wear off soon!

Why Does Skin Gets TANNED

Laying out on a beach without a care in the world sounds like an incredibly relaxing way to spend a summer’s day, but have you ever fallen asleep out there? With the sun beating down on you for hours, when you wake up, there’s a good chance that you’ll be a different color than when you first laid down!

Obviously sun-tanning is highly desirable for some people, but for others, it’s nearly impossible. While the person lying next to you may brown into a bronze god, you may just get a painful red sunburn. Doesn’t seem fair! It seems like we should get to the bottom of this…. why does sun tanning even happen? 

Well, the short answer is that tanning is our body’s way of signaling that damage is being done to our skin cells, as well as a way to protect ourselves from further harm. However, since we all enjoy a moment in the sun from time to time, perhaps this issue deserves a bit more explication.

Sunlight and Radiation

During your relaxing day at the beach, you probably don’t feel like you’re being bombarded by radiation, but that is precisely what sunlight is! In addition to visible light and heat, there are three types of ultraviolet radiation that come from sunlight: UVA, UVB, and UVC. We can basically ignore UVC radiation, as it never reaches the surface of the planet (or our skin) and is largely absorbed by the atmosphere.

UV Radiation Penetration (Photo Credit: designua / Fotolia)

However, UVA and UVB radiation do reach our sun-exposed skin, and have various effects. UVA radiation is much more common, and isn’t filtered out by our planet’s ozone layer. We are exposed to UVA rays throughout our lives, as they can even penetrate clouds and atmospheric gases. When UVA radiation strikes our skin, it immediately engages the melanocytes (the pigment cells in our skin), causing a release of the melanin they have already stored, resulting in what we know of as a “tan”.  UVA radiation penetrates deeper into the skin, and can damage skin cells in the epidermis, leading to various types of skin cancer.

UVB radiation is slightly different, however, and only penetrates the top few layers of the skin, and is primarily responsible for sunburns, rather than sun tans. This makes UVB less of a danger for deep-layer skin cancers, but it can contribute to melanoma and those uncomfortable sunburns.

DNA Damage: The Struggle is Real

Radiation of any kind penetrating the skin can damage DNA in those affected cells, which is why humans have adapted melanin – to repair and protect the body from that damage. When UVA radiation penetrates the skin, it causes the existing melanin to darken, but does not stimulate the production of more melanin. The color change resulting from UVA radiation is due to oxidative stress on the melanin, which changes its color. However, this is not a long-lasting color change, and the “tan” from UVA rays will usually fade in a few days.

UVB radiation is the key component in the second stage of the tanning process. The damage caused by UVB rays stimulates melanogenesis, the body’s natural response to radiation (producing more melanin). This type of tan will be much longer lasting, and actually protects your skin from further radiation damage, as the melanin produced will absorb that radiation. UVB radiation can typically be blocked by sunscreen, whereas UVA rays are more difficult to protect against; fortunately, natural and synthetic fibers (clothing) have been shown to protect against the majority of UVA rays.

Melanocyte and Melanin Process (Photo Credit: designua / Fotolia)

The melanin produced and released by melanocytes comes in two pigment forms: eumelanin (brown) and phaeomelanin (yellow and red). Depending on a combination of your hair color, skin tone, race, genetics, and previous exposure to sunlight, the production levels of these two pigments may be different. For example, a fair-skinned Irishman with red hair may produce less eumelanin than phaeomelanin, making it almost impossible for him to get a “tan” in the traditional sense. On the other hand, a Mediterranean woman with dark hair and an olive-skinned complexion may tan very easily, as her melanocytes produce more eumelanin than phaeomelanin.

  If you are of a race other than Caucasian, you’re particularly fortunate, as melanin production is almost continuous, ensuring that you always have a darkened skin tone and much more protection from radiation. For this reason, the occurrence of skin cancer in people from those cultures is much lower.

If you want to get a truly excellent tan, short bursts of exposure are recommended over the course of 5-7 days, as that will activate the melanocytes (through UVB rays) and start building up a protective layer of melanin. This will not only protect you from additional DNA damage and lower your chances of skin cancer, but also give you that sexy, toasted in the sun appearance you’ve been dreaming of all winter!