A common belief says that eating cheese causes vivid dreams or nightmares. However, I couldn’t find any support for the idea in the scientific literature except for one bizarre case study.
Although the case report really tells us nothing about the link between cheese and dreaming, it’s lovely to read because it’s from a bygone day where doctors could write into medical journals with their strange and idiosyncratic observations.
From a 1964 edition of the British Medical Journal:
I have lately seen a patient with moderate essential hypertension who because of various side-effects with other drugs was changed to pargyline, 25 mg every morning; this gave satisfactory control and within a fortnight the patient volunteered that he felt much less depressed, but was having nightmares.
Inquiry produced the fact that he habitually ate one or two ounces (30-60 g) of Cheddar cheese with his supper every evening. The nightmares were of a horrifying nature, and curiously they were concerned not with his immediate family or friends but with people such as his workmates, with whom he was not in any particular emotional relationship. He dreamt of one, terribly mutilated, hanging from a meat-hook. Another he dreamt of falling into a bottomless abyss. When cheese was withdrawn from his diet the nightmares ceased.
I am, etc. J. CHARLES SHEE, Bulawayo, S. Rhodesia.
The mentioned drug, pargyline, as well as being used for hypertension is in the same class of drugs more commonly used as antidepressants.
These are monoamine oxidase B inhibitors (MAOIs) which prevent the breakdown of the monoamine neurotransmitters serotonin, epinephrine and norepinephrine. However, they also prevent the breakdown of the chemical tyramine which occurs naturally in some foods, such as cheese, some soy bean products, processed meats and some fruit and nuts.
A build up of tyramine can cause an increase in blood pressure which can cause headaches, heart problems and increases the chance of stroke (blood vessel blockage or bleeds in the brain). Hence, people taking MAOI antidepressants have to avoid foods high in tyramine to prevent these potentially lethal side-effects.
Interestingly, the fact that the UK Prime Minister, Gordon Brown, was apparently avoiding similar foods led to internet rumours that he was on these antidepressants, which caused a media flap when the BBC questioned him about his mental health and use of “pills” to “get through”.
Link to PubMed entry for case study with full text option.