I don't really think you need a reason to drink Riesling.

However, if you are looking for one and suffer from headaches on a regular basis, then you might find the information in this article, Foods that Trigger Headaches, helpful.

It covers food and beverages as well:

List of foods and drinks to AVOID :

• Dairy products: Primarily ripened cheeses such as Cheddar, Emmentaler, Stilton, Brie and Camembert. Cheeses that are permitted include American, cottage, cream cheese and Velveeta. Migraine sufferers should have no more than 1/2-cup daily of sour cream.
• Meats and fish: Herring (either pickled or dried), sausage, bologna, bacon, pepperoni, salami, summer sausage, hot dogs, lunch meats, chicken livers and pâté.
• Fruits and vegetables: Broad beans, lima beans, fava beans, snow peas. No more than 1/2-cup daily of citrus fruits, figs, raisins, papayas, avocados or red plums. Less than 1/2 banana daily.
• Grains: Breads and crackers containing cheese or chocolate. Also sourdough bread.
• Other foods: Items containing monosodium glutamate (MSG) such as soy sauce, meat tenderizers or seasoned salt. Fermented, pickled or marinated foods, aspartame, chocolate, nuts, peanut butter and pizza.
• Beverages: Avoid excessive amounts of caffeinated beverages such as tea, coffee or cola drinks. Migraine sufferers should have no more than two cups daily. Limit yourself to two normal size alcoholic drinks selected from Haute Sauterne, Riesling, Seagram's VO, or Cutty Sark. Especially avoid red wine.