last month in las vegas, i met a dear friend, an athlete like most of us can only dream of dreaming to become and when the topic of wine came up, he told me that it gives him a headache and surely, he said, it must be from all those sulfites...

on my return, i decided to hit my wine books and do a mini-research on the subject to de-bug what i think is an urban legend. of course, i am not a medical professional and if any doubts remain after reading the information below, you should consult your physician...

here is what i discovered:

• the word "sulfites" on labels includes free sulphur dioxide, sulfurous acid, bisulfite ion, sulfite ion, and complex sulfite;
• sulfur has been used as a cleansing agent and wine preservative since antiquity;
• sulfur is an element that form 0.5 percent of earth's crust;
• it is essential for vine nutrition, naturally comes from the soil, and helps control mildew;
• sulfur dioxide, or so2 (when sulfur is burned in air), is used as a preservative and disinfectant and is an important antioxidant;
• it prevents oxidation, an undesirable effect on wine colour and flavour and it kills bacteria and wild yeast, both of which create off-aromas and off-flavours;
• it is widely (and more liberally) used in the preparation of fruit juices and dried fruits;
• less is required at a lower ph (high acidity), therefore, the warmer the climate, the more sulfur will be used because grapes, being riper, will have less acidity;
• 99 percent of all wine makers use it;
• it is more obvious on sweet wines, or wines (mainly white) from countries with a warm climate like australia, california, and chile;
• healthier grapes at picking, higher level of hygiene in the cellar, and more acidic wines need less sulfur dioxide;
• in europe the maximum permitted by law is 160 mg/l in reds and 210 mg/l in whites while in australia, the limits are 250 mg/l for any dry wines;
• wines made "organically", without the addition of any sulfur dioxide are prone to oxidation and off-flavours generated by wild yeast and bacteria;
• sulfur dioxide is in fact a by-product of fermentation (producing as much as 5-15 mg/l of so2) and therefore virtually all wines and other fermented products contain it (which means that it is also present in dough and fruit juices);
• in the usa, south africa, australia, and new zealand, it is obligatory to state on the label that a wine contains more than 10 mg/l of sulfur dioxide;
• the world health organisation has set the recommended daily allowance of so2 to be 0.7 mg per kg bodyweight which, for a person of 70 kgs, means an intake of 49 mg per day, or 1/3 of a bottle of wine;
• it is found in many foodstuffs as an antioxidant and preservative, especially, dried fruits, fruit juices, squashes, fresh fruit salads, sausages, peeled potatoes, and many others;
• most dried fruits are preserved with much higher levels of sulfites than most wines (as much as 10 times the level in some instances);
• most wine allergies and source of headaches actually comes from hystamine production caused by lactic acid bacteria produced during malolactic fermentation (this implies that reds are more prone to headaches and allergic reactions as malo is an essential step in its production as opposed to most whites which do not go through malo );
• it was documented that for a very small percentage of the population, sulfur dioxide was found to give an adverse allergic reaction to asthmatics and other air-borne allergens sensitive people and some doctors have suggested that asthmatics avoid wine altogether.

so, there you have it.  if drinking fruit juices and eating dried fruits does not give you a headache, then sulfites in wine will not more give you one. 

as i always say, the best way to avoid a headache is to stay hydrated and that means drinking plenty of water before, during, and after wine tasting.

(my information was found in: the science of wine from jamie goode and the oxford companion to wine edited by jancis robinson, the art & science of wine from james halliday & hugh johnson)