ALDH – The end of the line for histamine

When talking about allergies and histamine issues, we commonly bring up different environmental exposures like cat hair or pollen or dust.  But that's the short list.  If we keep digging into possible exposures and apply our growing knowledge of the genetics of histamine intolerance, there are some other big players we need to consider.

Introducing Acetaldehyde...

One of those is acetaldehyde.  Another funky chemistry name!  You may know more about this one than you think.  Acetaldehyde is a chemical found widely in the environment - both indoors and outdoors.  It comes from tobacco smoke, vehicle emissions, power plants, building materials and the like.  The foods and drinks we enjoy may also increase acetaldehyde in your body - things like alcohol, ripe fruits, dairy products, coffee and tea, and orange and lemon flavorings. 

And if you struggle with Candida, like many of us do, it is adding to the burden of acetaldehyde in your body by converting sugars to that very compound.  

Introducing ALDH...

Acetaldehydes can cause liver damage, osteoporosis and DNA damage which can increase risk for cancers.  Fortunately, your body has several enzymes called aldehyde dehydrogenases (ALDH) which help to clear acetaldehydes and get them out of your body via your kidneys.  

The function of your ALDH enzymes depends on your genetics and on the actual work burden for that enzyme in your body.  Just like the other genes and enzymes we've discussed, the activity of your ALDH genes may be coded to be fast or slow which will impact how well your body clears the compounds.  And, just like the others, there are ways you can support your ALDH genes to improve function for your unique situation.  

The Acetaldehyde and Histamine Intolerance Connection

But what does this have to do with histamine intolerance and food sensitivities?  Let's start to put it all together…

Think of an assembly line.  Each step along the line has to move in time with the others to keep the entire line moving.  If one step malfunctions or crashes, either the step before the crash keeps working and overloads the factory with the stuff it makes, or there is an emergency break which stops the entire line.  

In our histamine factory, we have two different histamine assembly lines.  (Technically, they are dis-assembly lines, but you get the idea!)  

The first line starts with Histamine which goes through DAO.  DAO turns histamine into imidazole acetaldehyde.  To get rid of that stuff, the ALDH family has to do its work and then it all goes out in urine.  End of the line.  

The second line also starts with Histamine but it then goes through HNMT and then the next step goes through MAOA.  MAOA makes N-methylimidazole acetaldehyde.  Again, to get rid of this stuff the ALDH family has to work its magic and then it also goes out in urine.  End of the line.  

If the ALDH step on either line doesn't work, that assembly line backs up…to a point.  Acetaldehydes are harmful to your body.  To protect your body from an accumulation of acetaldehydes, when levels of imidazole acetaldehyde or N-methylimidazole acetaldehyde reach a threshold, your body will actually turn off DAO and/or HNMT.  It's like the emergency brake to stop the whole line instead of allowing the lines to make too much acetaldehyde.  And if HNMT and DAO are not working, you will have an increase of histamine in your body.  

Don't underestimate the importance of ALDH

In the grand scheme of histamine intolerance and food sensitivities, it becomes really easy to focus on just HNMT or DAO because they are the two actually working on histamine…but if you don't support the entire system, it doesn't matter how much you try to push these two to work.  Your body is full of safety mechanisms…let them do their job!

The food sensitivity and histamine intolerance journey can be crazy frustrating…reactions frequently come from food items that don't make sense.  One day they cause a reaction and the next they don't.  We don't test positive for a particular food - with either allergy or sensitivity testing.  It just doesn't make sense.  

Until you start to learn about the biochemistry.  

Sixty-second Self-care Tip…

Let's get practical!  Most of us need to do a short-term (weeks, not months) low-histamine diet to allow biochemistry to clear histamine and allow your body to reset.  

When talking with folks about a low histamine diet, wine, beer and other adult beverages often come up.  Due to histamine levels in the beverage, fermented alcohol is going to be off limits but you can give vodka and soda a try.  Look for distilled spirits instead of fermented.  

But keep in mind alcohol is a source of acetaldehyde and, regardless of how it is made, it can still aggravate histamine intolerance by stressing ALDH.  

Next week we'll put a few more of the puzzle pieces together and I'll have a new download for you - Managing Histamine Intolerance with Vitamins and Minerals.


alcohol, ALDH, Candida, DAO, epigenetics, histamine intolerance, HNMT, MAOA

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