Wine contains alcohol. Alcohol acts on various parts of the human body, including the head.
Headaches are referred pain to the surface of the head from the deep structures, such as the brain and its related tissues, veins and arteries.
Pain is referred via pain receptors on the deep structures to either the front or the back of the head.
The headache experienced after consuming alcohol is generally related to your blood alcohol concentration (BAC). Alcohol and its primary breakdown product,
acetaldehyde, which are toxic compounds in high concentration, readily diffuse from the blood into the fluids of the brain and spinal cord. They directly irritate the meninges, which is the membrane that envelops the brain and spinal cord, to cause pain at the front surface of your head.
The more wine that you consume, the higher will be your BAC, the more the alcohol and acetaldehyde will irritate the tissues of your brain, and the more severe will be your headache.
It is possible that on some occasions the consumption of a wine will cause a headache and on other occasions it will not. Your BAC is related to the rate of alcohol consumption, such that absorption in the blood stream from the small intestine is rapid.
The alcohol is then transported in blood to the liver, which breaks down the alcohol.
The capacity of your liver to break down alcohol is limited, so that if more alcohol is presented to the liver than it has the capacity to break down, then the remaining alcohol will circulate in your blood to the other organs and tissues of your body, such as the brain.
The alcohol will remain circulating until it has all been broken down by the liver, to its primary breakdown product acetaldehyde, and then to its secondary breakdown product, acetate, which can be then be removed from your body by the kidneys or incorporated into cells.
The consumption of food, and even other non-alcoholic fluids, with the wine, will slow down and reduce the amount of alcohol that is presented to your liver for break down at any one time.
If you are taking certain medications, which are also broken down in the liver by the same mechanism as is alcohol, then the medications may be broken down in preference to alcohol. More of the consumed alcohol will circulate in the blood (and for a longer period of time), and you will record a significantly higher BAC, with the potential problem of a headache.
It has been suggested that a headache and an allergic reaction, such as facial flushing, following the consumption of wine may be due to the presence of biogenic amines, such as histamine, in wine. This appears unlikely.
Recent research shows that wine contains a very small amount of histamine, which is approximately 10-times less than that measured in other foods, such as cheese, fish and vegetables including eggplant, spinach and tomatoes.
These other foods are generally consumed daily and in large amounts, whereas the consumption of wine is generally not daily and only a relatively small amount is consumed.