As one of my favorite sitcom characters, Sheldon Cooper, would say "When people are upset, the cultural convention is to bring them a hot beverage." In my experience, a cup of tea or coffee can fix almost any problem, but why is that? Does a hot beverage really have magical calming or healing powers?
Can coffee clear a killer headache?
The caffeine in coffee can both help and hurt. In most cases, though, a cup of coffee or black tea could be in the answer to your mid-afternoon headache. Before you feel a headache coming on, your blood vessels have most likely already started to dilate. Due to its abilities to counteract vasodilation, caffeine can help fight off that pain. Although caffeine does have its benefits, in excess, it can cause withdrawal headaches if your body becomes too dependent upon caffeine (Source).
Lemon & honey tea: Nature's Cough Syrup
Anytime I have the slightest head cold or congestion, I crave lemon and honey in black tea. Is it just the comfort of this familiar "remedy" or actual science that gets me through the sick days?
As it turns out, science has much to say about this age old treatment. Lemon juice packs a full punch of vitamins A and C (crucial to a mobilized immune system) and act as an anti-inflammatory. Honey is a natural antiseptic and sore throat soother. The tea itself contains caffeine to help "wake up" brain cells in addition to providing steam to open up congested airways (Source).
Does warm milk make you sleepy?
Sadly this old wive's tale doesn't stand up to the chemistry. However there may be some strong psychological basis for this phenomenon. The idea of a warm beverage lulling you to sleep comes from the idea that humans generally fall fast asleep in warmer, cozy conditions. Although I would love to say that warm milk can noticeably lower your body temperature, I cannot. For warm milk to efficiently lower your core temperature, you would almost have to bathe in it. On the molecular level, milk contains tryptophan (the same amino acid said to make people drowsy after Thanksgiving turkey) which produces serotonin in the body inducing sleep. Contrary to popular belief neither turkey nor milk would induce the production of enough serotonin to jump start sleep.
Though the physical sciences debunk this remedy for sleeplessness, psychology may still uphold it. The sleep induced after a mug full of warm milk may be purely due to a psychological connection. As infants being fed a bottle or nursed, milk was quickly associated with comfort and safety. A cup of Kleinpeter dairy milk now could just transport our brain back to that place of warmth and peace (Source).
The magic of chicken soup
Since the 12th century, chicken soups and broths have been suggested as methods to fight the common cold. A cold generally arises from a viral upper respiratory tract infection in which virus encourage the production of intercellular proteins called cytokines. Cytokines direct the immune response on the cellular level, and when over stimulated they can cause inflammation. In addition, colds are often accompanied by mucous and a nasty cough. This is possibly caused by the presence of neutrophils which are in charge of mucous production for cells.
On several different occasions chicken soups were found to have anti-inflammatory properties. While it is still a mystery as to which biological and chemical factors are at play, chicken soup will mostly likely actually make you feel better (Source).