Thursday, October 2, 2014

Food Intolerances, Allergies, and Stress: An Overview

Of all the stimuli that we’re constantly adapting to, whether well or not so well, food is without question the most significant.  Think about it: There’s nothing that we’re exposed to as frequently, as intimately, as long as, or as much as in shear bulk as food.  What’s more, food, namely natural food, is highly complex chemically.  As such, food, like any other potential stressor, can elicit reactions that are “maladaptive” and chronic exposure to a food to which a person is sensitive can cause the same conditions that are caused by chronic stress — rheumatoid arthritis, thyroid imbalances, ulcers, headaches, obesity, hypoglycemia.

It’s no surprise that food sensitivities have been linked to and blamed for causing virtually every symptom in the books.  It’s also no surprise that a diagnosis is so difficult to make, and why there is so much controversy amid its existence.  I think the controversy surrounding the existence of food sensitivities was made famous by the work of the pediatric allergist Ben Feingold.

Feingold was sure that hyperactivity in children was caused by sensitivities to contaminants and additives in foods.  His diet for hyperactive children was free of all artificial colors, flavors, preservatives, propellants, nutritional supplements, etc., and though his idea was met with aggressive skepticism, there were/are sound reasons to argue for his theory, the most important of which was that many children benefited from the diet.

But food sensitivities can also exist to things that aren’t deliberately added to foods.  Antibiotics, arsenic, and steroid hormones are things added to the feed of livestock that end up in meat, milk, and eggs.  In addition, plant foods, even the highly hybridized ones, contain chemicals, such as salicylates that can be highly allergenic and irritating.  Other contaminants, such as lead, an industrial waste product, are taken up by grains, vegetables, and shellfish with a relatively high affinity, and evidence for this increased lead exposure can be found in our bones, which contain more lead than ever before.

Feingold and his theory aside, it’s important to understand that there are deliberately added and naturally occurring contaminants in food, which act as toxins, allergens, irritants, and/or carcinogens, that are regularly ingested, absorbed, and produce a wide range of physiological effects that may or may not be perceptible (at least in the short-term).   Sensitivity to these ingested contaminants is based largely on the effectiveness of our defenses against them.

There are primary three lines of defense against the contaminants with which we’re constantly confronted.

First, the GI tract, liver, and kidneys provide wide-ranging and general protection against these contaminants — provided they’re healthy and functional.  A person with lung problems, for instance, would be more susceptible to inhaled things, such as nitrogen and sulfur oxides.  A person with liver problems would be more susceptible to fat-soluble things because the liver converts fatty compounds into water-soluble ones, which can be removed by way of the kidneys from the blood.  And a person with kidney problems would be more susceptible to water-soluble things. 

Second, contaminants that reach the blood and tissues in the body can acutely activate the HPA axis to prompt the secretion of cortisol, which represents another line of defense.  Susceptible people are people who do not mobilize their adrenal (or thyroid) reserves to these contaminants; they are therefore relatively more sensitive to their environments.  Although the mechanisms are incompletely understood, cortisol and thyroid hormone protect against and mitigate sensitivities to contaminants by limiting the release of histamine and by raising blood sugar levels — a radical idea first put forth in the 1960s.

And third, a person’s nutrition status is an important line of defense that, compared to the other two variables, is within our control to improve and strengthen.  An adequate intake of calcium, magnesium, and zinc, for instance, by the principle of displacement/chelation, protects again lead, cadmium, and fluoride toxicity.  The kinds of fats and proteins in a person’s diet are a major factor, too.

A general distinction, however, should be made between sensitivities and intolerances so as to not mistake one for the other.  Think about milk for a minute. 

Milk is often avoided by most adults due to the distressing symptoms it causes: bloating, burping, cramping, farting, diarrhea, constipation.  These are symptoms of an intolerance to lactose because of a lactase deficiency.  Intolerances to foods, or more precisely to the components of foods, abound.  And identifying them isn’t always as easy as identifying lactose intolerances.  

Allergies, compared to intolerances, derive from antibodies produced against specific food proteins.  True allergic reactions are immediate and explosive versus intolerances, which are way more variable in their presentation.  One way to determine if an allergy is at play is to try milk from animals other than cows.  For instance, the ability to drink goat milk but not cow milk without symptoms strongly indicates an allergy, not an intolerance, as milk from all mammals contains lactose.[*][†] 

Allergies are harder to get around then intolerances, and if your unlucky to have an allergy, the surest fix is avoidance of the food(s) to which you are allergic.  On the other hand, intolerances can be overcome so long as the cause is identified — often easier said than done.  It’s been reported in forums that intolerances to milk can be gradually overcome.  The idea is that the regular consumption of milk will gradually stimulate the production of lactase.  This idea, though reasonable, is not supported by experimental data as far as I know.[‡]

Although allergies are more potentially lethal than intolerances, the latter is more widespread and easier to miss — which make intolerances more insidious.  There are three main reasons why clinical diagnoses for food intolerances are so elusive.

First, clinical symptoms arise from complex reactions to broken down products of food — most of which are unknown and/or inadequately studied.[§]  Second, the symptoms of food intolerances are extremely varied in quality, intensity, and duration, just as the manifestations of chronic stress are, and they can show up in any body system.  In addition to that, a particular food can produce different sets of symptoms in different people.  And third, the timing of symptoms can be highly unpredictable; that is, the interval between the exposure to a food and the occurrence of symptoms can vary among people and within the same person.

Regardless of whether an intolerance or allergy is at play, both are perceived of as stressors.  Stress, in turn, increases our susceptibility to allergies and intolerances.  As such, when exposure to foods and diets to which we are allergic or sensitive is prolonged or excessive, evil things are likely to ensue.

Chronic stress leads to the excessive secretion of ACTH, cortisol, GH, adrenalin, and glucagon — all of which eventually results in the following biochemical derangements (skip over this list if you’re uninterested in the grueling biochemical details):

1) Excessive accumulation of fat in places not meant to store much fat
2) Influx of water into cells and cellular swelling
3) Oxidation of fat and decrease in ATP generation
4) Oxidative stress
5) ‘Disorganization’ of the mitochondrial respiratory chain
6) Deposition of calcium in soft tissue

Cortisol is a major factor, as it potently causes the preferential oxidation of fat, which, for reasons I won’t get into here, promotes deficiencies in oxygen.  An oxygen deficiency stimulates specialized cells called fibroblasts, which secrete and lay down collagen (i.e., scar tissue), so as to increase the distance through which oxygen has to diffuse to reach cells.  In a vicious cycle, the oxygen deficiency intensifies, stimulating more collagen-secreting cells, which, in turn, lay down more collagen, and so forth. 

In the heart, for instance, a decrease in oxygen availability from excessive cortisol exposure can impair the heart muscle’s ability to pump blood while at the same time increasing the heart rate by stimulating beta-adrenergic receptors.  So although the cardiac output may be unaffected at first, over time, the reduced stroke volume results in less blood pumped per heartbeat, intensifying the oxygen deficiency further.[**]  Suffice it to say, cortisol is an important factor in cardiovascular disease.

Glucose, fructose, and insulin can help to prevent some of the consequences of excess cortisol exposure, especially in the heart.  Simply increasing blood glucose levels helps to reduce a person’s reactivity to allergies and intolerances and improves allergies and intolerances already established.  However, the reliance on cortisol or other adaptive hormones to do so, over time, has serious consequences, like the ones listed above.  Anything that inhibits phosphodiesterases or increases the metabolic rate reduces a person’s sensitivity by putting a brake on histamine release.  Choline, which synergizes with histamine in causing the ‘effusive’ symptoms of allergic reactions, can be blocked by anti-histamines, which is partly why some anti-histamines are also classified as anti-cholinergics.  Vitamin A protects against stress-induced tissue damage, including in the thymus and spleen.

We could deliberately expose ourselves to cortisol excessively, by replacing carbohydrate in our diet with fat, or by eating less frequently or not enough.  Chronic dieters get what I call the “face” with thickening of their mid sections and thinning of their extremities from excessive protein break down.  Call it a mild, sub-clinical form of Cushing’s combined with hypothyroidism.  Depression and irritability are not uncommon either.  But these ugly effects are really just the tip of the iceberg. 

Hans Selye said that every stressful event left a “scar.”  Conceptually, I interpret this in the following way: When there’s a mismatch between a stressor and the ability of our bodies to mount an adaptive response to restore balance caused by that stressor — in which case balance would only be partially restored — our bodies become that much more vulnerable to future stressors.  This imbalance carries over to the exposure to every subsequent stressor so as to put cumulatively more strain on our adaptive mechanisms until eventually the adaptive mechanisms collapse and disease results.[††] 

A diet that raises cortisol is a diet that by definition is stressful.  The surest way to raise cortisol through diet is to adopt a “ketogenic diet.”  There’s probably no faster way to “scar” the shit out of yourself than that.  I do urge people to tap into their senses and sensibilities for a second and kick dirt on the idea of becoming the “ultimate fat burning man” or “bulletproof” or “fat-adapted” or whatever.  These are made up ideas put forth by marketers masquerading as experts.  Diet-oriented marketers are sleazy and will say anything, seriously (stepping off soapbox now).

There are many causes and contributors to food allergies and intolerances.  It’s incredibly complex, yes, but it’s well known that stress predisposes to and aggravates both of them.  Environmental contaminants are rampant, more than ever, yet adjusting certain nutritional factors and raising blood sugar levels can protect against and reduce a person’s sensitivities to them, although the reasons why are not completely understood.  Discerning whether a food allergy or intolerance is at play becomes more difficult when considering allergies of the chronic, low-grade variety.  However, the symptoms of either one respond to the same interventions, evidenced by the fact alleviating one condition has positive effects on the other.  The adaptive hormones and mechanisms represent an important line of defense against the contaminants to which we’re commonly exposed.  Despite this, it’s important to understand that over reliance on these hormones and mechanisms have long-range effects that not only sensitize us to future exposures to contaminants, but they also sensitize us to other stressors — injury, illness, fatigue, noise, psychological strain, temperature changes. . . .

[*] Lactase (the enzyme that degrades lactose into glucose and galactose) is produced and secreted by mucosal cells of the jejunum.  When there isn’t enough lactase, lactose either move into the blood undigested, after which they are excreted in urine (minor pathway), or they pass into the colon, where they are fermented by bacteria to various acids and gases, particularly carbon dioxide (major pathway).

[†] There are two other simple tests that involve ingesting some lactose and either (1) waiting for symptoms or (2) measuring blood glucose levels shortly after.

[‡] I am, however, interested in anecdotes of people who have overcome lactose intolerances this way.

[§] This is why skin testing is useless.

[**] A similar situation occurs at high altitude.

[††] This is also how Selye conceived of the aging process, and there’s good evidence to support his model.