DAO or DOA? -What happens when the body loses its ability to regulate histamine?

By Dustin Strong, CHN, ACN

Over the last few years, more and more people have begun asking about DAO supplements.

Not because DAO suddenly became trendy…

…but because more people are struggling with symptoms that may be connected to histamine imbalance:

• headaches

• flushing

• anxiety

• insomnia

• hives

• congestion

• digestive issues

• rapid heartbeat

• dizziness

• feeling “inflamed” after certain foods

This has led many people to discover something called:

DAO (Diamine Oxidase)

And once they look into it, they often find something surprising:

Most DAO supplements are made from…

porcine kidney extract.

That alone should make us pause and ask:

What exactly is going on here?

Because the deeper story may be much more fascinating than simply:

“take an enzyme.”

What Is DAO?

DAO (Diamine Oxidase) is an enzyme primarily responsible for breaking down histamine outside the cells...especially histamine coming from foods.

Your body naturally produces DAO, particularly in:

• the small intestine

• kidneys

• thymus

• placenta

When DAO activity is low, histamine may accumulate faster than the body can clear it.

That can potentially contribute to symptoms associated with “histamine intolerance.”

Why Would the Body Stop Producing Enough DAO?

This is where I believe the conversation becomes much more important.

Because the body is SUPPOSED to make DAO.

So instead of only asking:

“Should I take DAO?”

we should also ask:

“Why did endogenous DAO production decline in the first place?”

And honestly?This may be another example of:

death by a thousand physiological cuts.

Not one catastrophic event.

But years of:

• inflammation

• gut irritation

• nutrient depletion

• stress

• poor sleep

• environmental burden

• processed food

• microbial imbalance

• toxic exposures

slowly reducing resilience over time.

The Gut Connection

DAO is produced largely by the cells lining the small intestine.

This is extremely important.

Because if the intestinal lining becomes irritated or damaged, DAO production may decline.

Potential contributors include:

• chronic stress

• alcohol

• ultra-processed foods

• infections

• inflammatory bowel conditions

• mold exposure

• certain medications

• food sensitivities

• chronic inflammation

This may help explain why some people suddenly become sensitive to foods they previously tolerated for years.

Nutrient Deficiencies May Matter More Than People Realize

The body cannot build enzymes out of thin air.

DAO production appears to depend on several nutrients, including:

• copper

• vitamin B6

• vitamin C

• magnesium

• zinc

• adequate protein intake

This creates a very different perspective.

Sometimes the issue may not truly be:

“DAO deficiency”

but rather:

“the body lacks the raw materials needed to build and protect DAO.”

That is a fundamentally different conversation.

The Histamine & Hormone Connection

One of the most fascinating areas of research involves the relationship between:

• histamine

• estrogen

• DAO

Estrogen may:

• increase histamine release

• reduce DAO activity

This may help explain why some women notice worsening symptoms:

• around ovulation

• during perimenopause

• during periods of hormonal fluctuation

Interestingly, the placenta produces enormous amounts of DAO during pregnancy.

Nature rarely does things without reason.

Is Histamine the Problem… or Is the Body Overwhelmed?

Another important distinction:

Sometimes the issue may not be poor histamine breakdown alone.

Sometimes the body may simply be producing or releasing too much histamine.

This brings us into conversations about:

• mast cells

• inflammation

• mold exposure

• chronic infections

• nervous system stress

• environmental toxins

In other words:

the body may not be “broken.”

It may be overloaded.

The Food Problem Nobody Talks About

Histamine naturally accumulates in:

• aged foods

• leftovers

• canned foods

• smoked foods

• fermented foods

• improperly stored foods

Modern food habits may unintentionally create:

a high-histamine lifestyle

especially when combined with impaired gut integrity and chronic stress.

This may help explain why histamine issues appear to be increasing.

Why I Don’t Think DAO Supplements Are the Whole Story

DAO supplements may absolutely help some people temporarily.

But I do not believe the ultimate goal should simply be:

“take more DAO forever.”

The bigger goal should be asking:

What would help the body regulate histamine more naturally again?

That may involve supporting:

• gut integrity

• nutrient sufficiency

• nervous system balance

• sleep quality

• inflammation reduction

• liver and bile flow

• microbial balance

• toxin reduction

• stress resilience

Because the body is designed to manage histamine.

The question is:

what interfered with that design?

A Whole-Systems Approach to Histamine Support

Instead of focusing only on suppressing symptoms, a broader strategy may include:

Improve Food Freshness

Temporarily reducing high-histamine foods while prioritizing fresh, minimally processed meals.

Support the Gut Lining

Helping restore intestinal integrity and digestive function.

Restore Nutritional Building Blocks

Focusing on:

• magnesium

• B vitamins

• zinc

• copper-containing foods

• vitamin C

• protein sufficiency

Reduce the “Physiological Cuts”

Improving:

• sleep

• blood sugar balance

• stress regulation

• toxin exposure

• inflammatory burden

Because all of these influence resilience.

Final Thought

I find the DAO conversation fascinating because it reveals something much deeper than histamine alone.

It reminds us that health depends on:

• specialized enzymes

• nutrient sufficiency

• healthy barriers

• resilient physiology

• environmental compatibility

And modern life may slowly erode those systems over time.

Not usually through one catastrophic event…

…but through:

death by a thousand physiological cuts.

The hopeful part?

If physiology can slowly lose resilience…it may also be capable of slowly rebuilding it.