Charged 2026

Author: Lauren Mellinger

  • ‘IN Synch

    Written by: Lauren Mellinger and Julia Raver

    Every girl knows what it feels like during “that time of the month” – bad cramps, mood swings, you name it. And it seems that other girls can always tell when it’s time. There have been many studies on the correlations of menstrual cycles between best friends, teammates, or even roommates. But do menstrual cycles really sync up? 

     

    [ sea-nsory details ] 

    One study claims that menstrual cycles sync based on olfactory cues. So what are olfactory cues anyways? Olfaction, the sense of smell based on chemical cues in the environment, has significant effects on animal behavior (Brady et al., 2012). Specific olfactory receptors within the body react either positively or negatively to different chemical scents. This transfers specific information to olfactory centers (Ruta, 2021). 

    These olfactory centers have pathways to the amygdala (which triggers a fight or flight response), lateral hypothalamus (the hunger center which controls feeding behaviors), and the insular cortex (links sensory and emotional experiences).The location where the centers deliver information determines feelings and sensations. For example, it determines when you’re hungry, if you’re swimming, or if you’re happy or sad (Russell et al., 1980). 

    A study treated two groups of women on their upper lips with an alcohol-based mixture 3 times a week during a span of 4 months. One group was treated with plain alcohol and the other was treated with a mixture of alcohol and underarm perspiration from a single donor. They found that the women’s cycles treated with the donor’s perspiration scent ended up having significant menstrual cycle shifts towards the cycle of the donor (Russell et al., 1980). 

    So one potential source of synching could be exposure to specific chemicals in the environment. Imagine you are constantly working out with your sports team and sweating together, it is possible that your cycles could sync due to the exposure of each other’s underarm perspiration. 

     

    [ reely great roommates ]

     

    Another study performed by Martha McClintock studied the cycles of undergrad roommates over the entire year. In October, the cycles were on average 8.5 days apart, but, by March, they were about 5 days apart. On the other hand, randomly matched pairs showed no synching (Strogatz, 2022). There was no science, however, behind this discovery, only physical closeness to cite. 

     

    [ knot just a phase ] 

    A final theory is that lunar cycles play a factor in menstrual synching. The study found that cycles lasting longer than 27 days historically had intermittent synching with both the Moon’s luminance and gravimetric cycles (Helfrich-Förster, 2021). The luminance cycle is the light intensity of the Moon in each lunar phase. The gravimetric cycle is the difference of the Moon’s pull when at different positions with respect to the Earth (Cohut, 2021). 

     

    The study found that women with cycles around 29.5 days, or the period of the moon, have the highest likelihood of becoming pregnant. There was also a correlation found between the three lunar cycles – the synodic, the anomalistic, and the tropical month – and the onset of menstrual cycles. These trends however hold much stronger in ancient times. Back then there weren’t as many societal impacts like stress and nutrition on the duration and frequency of the menstrual cycle (Cohut, 2021). So studies point to a historical linkage, although it doesn’t necessarily hold true in today’s time. 

     

    [ hook, line, and sink-her ]

    Despite all this data and our strong desire to connect over shared pain, estrous synching is a weak phenomenon at best. Researchers have tried over and over — with roommates, best friends, and even rats — and nearly all of them come back with mixed findings. 

    [ un-sync-able studies ] 

    In the largest study ever taken on, data was collected from 186 women who lived in dorms together for over a year. None of the menstrual clusterings were stable or occurred more than by expected by chance (Yang & Schank, 2006).

    A similar study with sorority sisters excluded those taking oral contraceptive and those with irregular cycles. Still no signs of menstrual synchrony (Wilson et al., 2003). 

    Among a women’s basketball team, spending time together was actually found to be negatively related to synchrony, as was exercising. If the theory that pheromones are the source of synching cycles was true, exercising with one another should be positively associated with synchrony (Weller & Weller, 2000). 

    Data from Clue, a popular period tracking app didn’t support McClintock’s conclusion either. Data from over 1500 users demonstrated that being in close proximity with another menstruator likely does not disrupt your cycle. Over 75% of pairs actually had a bigger difference in cycle start dates by the end of the study (Ray, 2022). Based on this data, your cycle would be more likely to diverge than converge with another person’s!

     

    [ like rats abandoning a sinking ship ]

    Observing 10 pairs of female rats, unsurprisingly, there was no effect of synchrony (Schank, 2001). Thus, the belief that there is some biological or evolutionary explanation loses its stability, too.

     

    [ the synching ship of menstrual synchrony ]

    From all this evidence, we can see that the popular belief of “living together, bleeding together” has pretty much been debunked.

    Let’s say a typical cycle length is 28 days. The maximum that two women could be out of phase is 14 days. On average, these onsets will be 7 days apart, and half the time they should be even closer. Since the average menstrual cycle lasts 5 days, it’s not surprising that friends or roommates commonly recall experiencing overlaps, falsely confirming the myth (Strassmann, 1999). When we do see overlap, statistics says its due to coincidence supported by math rather than biology.

    When you think about how much variation there is not only between menstruators but within each individual, finding proof of synchrony is virtually impossible! There are just too many obstacles in the way that reduce the potential for consistency, like birth control, energy levels, stress, weight, genetics, and age (Strassmann, 1999).

    Harsh as it may sound, the studies where synchrony was found may have been plagued with methodological errors (Rudis, 2008). This should not be cause for worry though. Variability between women may be necessary and inherent to our physiology and the process of ovarian cycles (Schank, 2000). In an evolutionary context, avoiding synchrony would enhance female choice among males and reduce competition among females. Within-woman variability would also reduce the chance of males predicting the next ovulation and controlling the matings of females (Schank, 2000).

    The claim that cycles dominate on phases of the moon has no leg to stand on either. No one is quite sure if they are set to the full moon, new moon, or somewhere in between.

    [ to sync or swim ]

    What it comes down to is a simple matter of math and time. I advise you to be careful not to mistake the ebb and flow of cycles over time as synchronization. However…

    There’s no harm in bonding over the magical (and miserable) mystery that is menstruation. I think it’s a positive way to find comfort with other women who might be going through the same thing. So, what do you think?

     

     

    [ sources ]

    https://www.medicalnewstoday.com/articles/menstrual-cycles-and-lunar-cycles-is-there-a-link#:~:text=The%20luminance%20cycle%20refers%20to,it%20orbits%20around%20our%20planet. 

    https://modern-cynic.org/2021/01/12/corporate-rats-desert-a-sinking-ship/ 

    https://doi.org/10.1080/23293691.2016.1150132

    https://doi.org/10.1126/sciadv.abe1358 

    https://www.gynecajournalcu.org/blog-articles/staff-writing/do-periods-actually-sync.html

    https://www.empowher.com/media/reference/true-or-false-women-who-live-together-tend-have-synchronized-menstrual-periods

    https://doi.org/10.1016/0091-3057(80)90020-9 

    https://www.rockefeller.edu/news/30838-study-reveals-smell-receptors-work 

    https://www.sciencedirect.com/science/article/pii/S0306453000000299

    https://www.sciencedirect.com/science/article/pii/S0031938400003954

    ttps://academic.oup.com/humrep/article/14/3/579/632869?login=true

    https://ieeexplore.ieee.org/abstract/document/638513 

    https://modernfertility.com/blog/cycles/

    https://www.sciencedirect.com/science/article/pii/030645309500007B

    https://doi.org/10.1016/S0306-4530(01)00102-0

    https://www.sciencedirect.com/science/article/pii/030645309190021K

    https://doi.org/10.1007/s12110-006-1005-z

    https://doi.org/10.1007/s12110-006-1004-0 

  • Coffee Chemistry

    Written by Julia Raver and Lauren Mellinger

    Coffee – an integral part of your morning routine. You wake up and groggily walk to the kitchen to make your morning cup. It has become so integral to our morning routine that a lot of people can’t function without it. Especially in the mornings, having your order messed up at Starbucks or Dunkin Donuts can change the trajectory of your entire day. But how does coffee keep you awake all day? Caffeine is the secret to coffee’s success. 

     

    Part 1 – The Chemistry

    Caffeine, or C8H10N4O2, is a drug known for its ability to give you energy and boost metabolism. It functions very similarly to xanthine, which is a crystalline drug that is often found in chocolates and teas. This provides an increase in stimulation and wakefulness, the ability to sustain intellectual activity, and decrease in reaction times. In the image below, you can see the similarities between the xanthine and caffeine molecules. The main differences are that caffeine has extra methyl (or CH3 groups) attached to its two rings (National Academy Press, 2001).

    Due to the polarity in caffeine molecules, or difference in strength between the nitrogen and oxygen bonds, caffeine exhibits unique bonding forces. It can bond via dipole-dipole forces, where positive and negative atoms of different molecules bond together. Caffeine also bonds via hydrogen bonding with water, which is a strong bonding of hydrogen atoms with carbon atoms of water and caffeine respectively. In layman’s terms, caffeine reacts in the bloodstream by bonding via its nitrogen and oxygen atoms. 

    Absorption in the Bloodstream

    We can now dive deeper into how caffeine is absorbed in the bloodstream. People absorb caffeine within 45 minutes of ingestion but has an elimination half-life of anywhere from 1.5 to 9.5 hours. This means that if you drink your morning coffee at 8 am, it could still be in your system at 5:30! When absorbed, caffeine undergoes the hepatic first-pass effect, meaning it is not removed by the liver and heads straight for the bloodstream. There, due to the presence of carbons within the structure, caffeine acts as a hydrophilic (or water-liking) molecule and can bond with the water in your tissues. Once bonded with this tissue water, caffeine works with proteins and begin to give you that energy boost you so desperately needed when you drank it at 7am (National Academy Press, 2001). 

    Now remembering that caffeine is in fact a drug, it is important to note that it also comes with a certain toxicity level. Luckily for coffee drinkers however, caffeine only becomes fatal when around 10-14g are ingested daily. To get an idea of how much this really is, divide 150 or 200 by your total body weight in kilograms. This gives the toxicity level based on your weight per day (National Academy Press, 2001). For example, if you weigh 110 pounds (or 50kg), 7500 milligrams or 7.5 g of caffeine is your daily toxic dosage of caffeine. An average cup of coffee contains around 100 mg of caffeine so you would need to drink 75 cups of coffee in a day to die of caffeine overdose (Dews, 1982).

    Caffeine Appearance

    Caffeine is what helps coffee give you energy in the morning but what makes coffee look and taste how it does? Melanoidin, or heterogeneous polymer with a brown pigment, is formed when sugars and amino acids combine at high temperatures (Merriam-Webster). This melanoidin is what gives coffee its nice rich brown color. Depending on the temperature to which the coffee beans are heated, the coffee can taste differently. Once heated above 180 °C, exothermic reactions (that release heat) within coffee beans occur (Rao, Fuller, & Grim, 2020). 

    The reactions occurring at these high temperatures are called Maillard reactions, which are defined as reactions between amino acids and sugars. Basically, sugars and amino acids reacted at high temperatures produce brown products, or these melanoidin molecules that create brown pigments (Ellis, 1959). Therefore, different roasting temperatures cause these reactions to go to either more or less completion and are responsible for both the color and taste of your morning beverage. Now that we understand the chemistry behind caffeine, we can look at flavor preferences.

     

    Part 2 – The Psychology

    Cold beverages have accounted for 75% of Starbucks’ sales in the past quarter (Creswell, 2022). All across the world, coffee drinkers prefer the mellow, balanced flavors of cold coffees. Hot coffee, on the other hand, can only be enjoyed for the fleeting moments between scalding and sour. But why is it that the same beans can produce such different flavors?

    The Making

    The final cup of coffee is affected by the extraction method — the way water pulls flavor, aroma, and caffeine from the grounds. This is strongly influenced by temperature and time.

    For example, in a pour over, water moves over the coffee and produces a brighter tasting coffee. Immersion brews result in a fuller extraction leaving more body in the cup (Kelly, 2018). The cold brew method taking the coffee world by storm involves lower temperatures than your typical drip coffee. To compensate, it needs a much longer extraction time (between 8 and 24 hours) (Córdoba et al., 2021).

    Coffee and the Senses

    The ability of substances to dissolve out of the grounds and into the water increases with temperature. This causes acids to extract more efficiently in hot brewing. In turn, more sour and bitter elements are released. (Córdoba et al., 2021). Using a lower temperature better retains those delicate flavor components that would degrade or evaporate with exposure to heat (Lane et al., n.d.). Plus, hours of contact with water causes the fats in the beans to emulsify, creating that creamy mouthfeel. Therefore, higher temperatures lead to more nutty, roasty notes — and possibly some unsavory ones as well. Colder temperatures retain flavor compounds and generate a smoother, sweeter beverage (Córdoba et al., 2019).

    When you walk into a coffee shop, you are guaranteed to be welcomed by the scent of roasted beans. But you might notice that your cup of cold brew doesn’t smell very strong at all. Since the oils that carry aromas remain in the water, they stay in your coffee. You’ll perceive these as cold brew’s characteristic floral and fruity flavor (Oden, n.d.). Your drink might not have a strong fragrance or bite, but cold brew rewards those who wait (Alkin, 2014).

    Is Cold Brew Better?

    The novel brewing method also extracts more caffeine with time, which means cold brew is a concentrate. This allows coffee drinkers to adjusted it to their preferred strength and endlessly customize it to their liking. In addition, the lack of acidity may mean cold brew is a better alternative for those with sensitive teeth, heartburn, or GI issues (Rao & Fuller, 2018).

    Whether you crave the smokiness of an automatic drip, or the natural sweetness from an hours-long immersion, ultimately, the choice of brew is up to you.

     

    Reference List

    • https://www.scienceandfood.org/coffee-brewing-chemistry-hot-brew-and-cold-brew/
    • https://www.sciencedirect.com/science/article/pii/S0924224419305692
    • https://www.nytimes.com/2022/08/02/business/starbucks-quarterly-earnings.html
    • https://www.sciencedirect.com/science/article/pii/S0963996921000387
    • https://www.sciencedirect.com/science/article/pii/S0023643821005168
    • https://doi.org/10.1146/annurev.nu.02.070182.001543
    • https://doi.org/10.1016/s0096-5332(08)60223-4
    • https://blog.lacolombe.com/2018/09/19/brewing-method-affects taste/#:~:text=Immersion%20and%20pourover%20brewing%20each,%E2%80%9D%2Dtasting%2C%20brighter%20coffee
    • https://journals.uvic.ca/index.php/arbutus/article/view/16816
    • https://www.merriam-webster.com/medical/melanoidin
    • https://www.ncbi.nlm.nih.gov/books/NBK223808/
    • https://www.javapresse.com/blogs/cold-brew/hot-brewed-vs-cold-brewed-coffee
    • https://www.nature.com/articles/s41598-018-34392-w
    • https://doi.org/10.3390/foods9070902