Just one apple a week significantly reduced the incidence of both allergies and asthma. A similar benefit accrued from eating just one orange a week.
A later study of London school children aged 5 to 10 found that drinking apple juice (made from concentrate) at least once a day did not stop each and every asthma attack, but drinking apple juice or other fruit juice for breakfast measurably reduced wheezing. And a Dutch study determined that women who eat apples during pregnancy bear children at lower risk for the atopic diseases, allergies, asthma, and eczema.
The European experience and subsequent laboratory studies in Japan suggest that the reason an apple a day (or even an apple a week) may keep atopic conditions in check is due to the fruit's content of quercetin.
This antioxidant flavonoid blocks the action of an enzyme called hyalouronidase. Hyalouronidase breaks down capillaries that cause stuffiness in the nose.
Hyalouronidase also breaks open tiny packets inside mast cells fileld with histamine, which, as you probably know, is the agent of allergic inflammation that anti-histamines are designed to counter. Getting quercetin from foods like apples blocks the action of the enzyme and keeps histamine from being released.
Eating foods rich in quercetin not only lowers risk of allergy, asthma, and eczema, it's associated a lower risk of lung cancer, too.
If you can't eat an apple a day, you can also get your quercetin from:
- Red wine, or
- Black tea
Certain other foods, however, can wipe out the allergy-protective effect of quercetin. These foods are high in the amino acid histidine, which the body can convert into histamine. High-histidine foods include:
- All game meats, especially arctic game meats (seal, whale), but also boar, antelope, and venison,
- Baked or dried tofu,
- Soy protein isolates (like you'd get in a soy supplement powder for making protein smoothies),
- Bacon, and
- Powdered eggs (which appear in all kinds of dry mixes for cakes and cookies).
So, an apple a day may keep allergies away, and blinky tuna may make them work. Try eating apples, oranges, grapefruit, onions, beans, peas, lentils, legumes, or green leafy vegetables and drinking black tea every day, and see if you allergies don't get better.