MALAYSIANS may not be the world's biggest cheese consumers but a good wedge of cheddar on a cracker or a slice of Gouda on a burger in not uncommon.
Whispers have been going around that gorging on aged cheese could do more than just expand your waistline, with some claiming it could actually affect your vision.
Can eating too much aged cheese really make you go blind?
Verdict:
TRUE (with caveats)
Eating aged cheese cannot directly cause blindness but a compound in it called tyramine can trigger migraines in susceptible individuals – those migraines can, in some cases, cause temporary visual disturbances including brief episodes of partial or total vision loss.
Tyramine is a naturally occurring compound produced when proteins in food break down during ageing, fermentation or curing.
According to StatPearls, published by the US National Institutes of Health, tyramine is found in high concentrations in aged cheeses such as cheddar, blue cheese, brie, Parmesan, Swiss, feta and Camembert, among others.
Under normal circumstances, the body handles tyramine quietly and efficiently. An enzyme called monoamine oxidase A (MAO-A), found in the gut and liver, breaks it down before it can enter the bloodstream. For most, a generous serving of aged cheese produces no ill effects whatsoever.
The problem arises for people with lower MAO-A activity, often due to genetics, or those taking antidepressants. In these individuals, tyramine bypasses the body's defences and enters the bloodstream, triggering a cascade of effects including the release of norepinephrine, a hormone that raises blood pressure and affects blood vessel behaviour.
According to a study, tyramine has a measurable effect on the central nervous system of migraine sufferers and is implicated as a trigger for attacks in a subset of patients, particularly those with established food-related migraines.
That said, the scientific evidence is not as clear-cut as some found that while headaches occurred in 17% to 50% of people after tyramine ingestion; placebo groups showed headache rates of 0% to 42%, making it difficult to isolate tyramine as the definitive cause.
Saying around 7% of migraine sufferers consistently identified tyramine as a personal trigger.
Where vision comes in is through the phenomenon known as migraine aura. According to a peer-reviewed review examining the neuro-ophthalmology of migraines, aura symptoms can include scintillating scotomas, the appearance of shimmering zig-zag shapes or expanding blind spots, as well as temporary vision loss affecting one or both eyes.
These symptoms arise from a wave of electrical activity across the brain's visual cortex known as cortical spreading depression and typically last between 20 and 30 minutes before resolving completely and are not indicative of permanent eye damage.
In rare cases, a subtype called retinal or ocular migraine can cause temporary total vision loss in one eye for up to 60 minutes, according to the Cleveland Clinic.
In extremely rare cases, migrainous infarction, a migraine-associated stroke affecting the visual cortex, can lead to permanent vision loss, though this is not caused by cheese consumption specifically but by the complex neurovascular effects of severe migraine.
So the short answer for those who enjoy aged cheese is this: for the vast majority of people, cheese poses no threat to your vision. But if you are among the minority of migraine sufferers who find that certain foods trigger attacks, aged cheese is worth keeping an eye on, pun fully intended.
Sources:
1. https://www.ncbi.nlm.nih.gov/
2. https://pmc.ncbi.nlm.nih.gov/
3. https://pmc.ncbi.nlm.nih.gov/
4. https://www.ncbi.nlm.nih.gov/
5. https://www.mayoclinic.org/
6. https://www.brighamandwomens.
7. https://my.clevelandclinic.
8. https://eyewiki.org/
