How many of us deal with allergies or asthma in our families?

In my own family, my son and I have seasonal allergies. His are bad enough to trigger asthma attacks. Two doors down, there are severe peanut allergies. Around the block, there are egg, gluten and dairy allergies, plus a few cases of excema.

If it seems like kids today have more allergies than when we were kids, you're right. In fact, since 1996, there has been a 400% increase in allergies.

Allergies, asthma, excema--all of these are a result of substances - from the air, our food, chemicals we use to clean our homes or clothes - that our immune systems perceive as intruders who must be attacked. So what's the intruder? Why are our immune systems going into overdrive?

I recently attended a lunch with Robyn O'Brien, the founder of AllergyKids.com and author of "The Unhealthy Truth: how our food is making us sick and what we can do about it." It got me wondering if the "healthy" food we eat is really all that healthy.

Take milk, that basic building block of the healthy American diet. It's the mainstay of infant and toddler diets. My 5 year old loves his glass of milk, at least 3 a day. When I was pregnant, milk, cheese yogurt or ice cream were sometimes the only things I could stomach.

Then suddenly, with a post-partum thyroid disorder, I discovered I was allergic to dairy. Why would I develop an allergy to dairy when I'd been eating it all my life? Is there some new, foreign substance that my immune system is attacking?

Correlation is not causation, but did you know that in 1996, 1/3 of American dairy cows began to get injections of rBGH, a genetically modified recombinant bovine growth hormone? This hormone keeps the nursing cows lactating for basically their entire adult life (imagine that, moms!). Longer lactation = more profits. Makes sense.

But it also results in sicker cows, with lots of cases of cow mastitis. Ever get that when you were nursing? It's a very painful infection. It requires antibiotics to clear out the pus, both of which get into the milk  (yuck). And it's reasonable to assume that this hormone might be in the milk, too, and might be affecting us in unexpected ways. If you have a little girl, do you want to take the chance of exposing her to hormones that might bring on early puberty? If you have a little boy, do you want to expose him to that?? Do YOU want it?

If you're like me, you might think, "But I don't drink milk." Except in my latte. But I do eat cheese, yogurt, butter, and ice cream. And Nutella and M&M's and Mac 'n Cheese and baked goods.

It might interest you to know that the use of rBGH has been banned in Europe, Canada, Australia, Japan and every other industrialized nation except the United States.

I don't know about you, but this information scares me.  I'm also the kind of person who gets paralyzed when overwhelmed with too much information. I can't change our food supply. I can't change the dairy industry.

What can I do?

I can't change my entire family's diet overnight.

But, as Robyn O'Brien says, everyone can do just one thing. As moms, we owe it to our kids to make sure they're not ingesting hormones made in a lab until we know for sure they're safe. If British moms can do it, so can we.

So if you could do just one thing this month to make your family healthier, stop buying any dairy products made with milk containing rBGH. 

So how do you know if your milk has rBGH in it?

• If it's not labelled as rBGH free, you can assume it's got rBGH.
• If it's organic, it's rBGH free.
• If you get your milk from a local dairy, like Royal Crest, ask them. Royal Crest is rBGH free (although not organic).
• If it's processed food, research it. Yoplait and Dannon listened to consumer demand, others will too.

One of the first things Robyn changed in her house was to stop buying the sugary, bright blue processed yogurts for her kids. She replaced them with white yogurt, and let her kids put sprinkles on top. Hey, it's a start!

What have you done to get your family eating healthier? Share your story in the comments and you could win some prizes from Stonyfield Farm Organic Yogurt, including

• A copy of "The Unhealthy Truth"
• A Stonyfield Farm Yogurt cookbook
• Coupons for free Stonyfield Farm YoBabies and YoKids Organic Yogurt
• Coupons for free Stonyfield Farm Oikos Organic Greek Yogurt

Check out what other moms who were at lunch with Robyn have to say: