Oxalates, Phytates and Saponins: The Secret Anti-Nutrients In "Healthy" Foods

Share this post TFUPM Posted April 09, 2014

It's happened many times that a certain food rose to popularity as a "health food" only to later fall from that status when we learned more about how the food is produced or a negative effect it has on the body.

Remember when "whole wheat" was considered a health food?  Now we know wheat creates holes in your gut lining and triggers systemic inflammation. 

Or soy, which seemingly every "healthy" person had in their fridge 10 years ago.  Soy milk has been largely replaced by almond milk over the past 10 years - in large part because it's now widely known that natural chemicals in soy have estrogen-like effects and soy is particularly susceptible to contamination by mold toxins.  

Well, there's now a new wave of "healthy" foods coming under scrutiny.  The issue this time around is natural plant toxins.

What Are Plant Toxins? 

Plant toxins are natural compounds produced by a huge number of plants, including many we grow as crops.  In most cases, these toxins are defense mechanisms the plant produces to protect itself against being overeaten by insects in its environment.  

If an insect eats enough of a one of these plants, the toxic chemicals would accumulate in the insect to a level where cell and tissue function are disrupted and the insect dies.  In this way, plant toxins play an important role in nature's checks-and-balances system. 

We now know that these same plant toxins that disrupt cell function in insects can potentially have the same effect in our own bodies.  Unless you're eating half your body weight in plant-matter in a single meal the way an insect might, plant toxins aren't going to kill you, but over time they certainly can have a significant impact of several of our body's systems. 

So how much (or how little) do we need to worry about these natural toxins in our food?  Depends on what you're eating.

First, let's cover the 4 main types of plant toxins, how they each affect the body and which foods contain these toxins in levels significant enough to warrant concern.

1. Phytates

WHAT PHYTATES DO: Phytates bind to minerals in your gut, preventing them from being absorbed by your body.  Suppression of iron absorption by phytates is what tends to get the most attention, but zinc, calcium and phosphorus are also affected.  [1]  A recent study has even suggested that diets heavy in phytates are responsible for the widespread zinc deficiencies seen commonly in the developing world. [2]

WHICH FOODS?: Beans, grains, seeds and legumes.  Beans are the biggest concern.

CAN PHYTATES BE REMOVED?: Soaking, sprouting and fermenting all reduce phytate levels, but do not eliminate them.

2. Lectins

WHAT LECTINS DO:  Lectins disrupt the functioning of the epithelium, the oh-so-critical thin layer of cells lining your gut that keeps undigested food from slipping into your bloodstream.  Over time, lectins in the diet will actually create holes in the epithelium, referred to as "leaky gut syndrome".  [3]

When the epithelium is compromised, incompletely-digested particles from your food can slip into your bloodstream.  Your body treats these food particles as a threat and triggers an immune response that creates systemic inflammation.  This is a similar mechanism to how wheat gluten creates holes in the epithelium

Lectins have also been shown to disrupt gut bacteria function, which given how critical these bacteria are to our well-being, is a major concern as well.

WHICH FOODS?: Beans and grains again.  Soy beans and kidney beans are the biggest concerns.

CAN LECTINS BE REMOVED?: Cooking and fermenting reduce lectins, but do not remove them.

3. Saponins

WHAT SAPONINS DO:  Saponins actually have a soap-like foaming property when they're added to liquid.  In part because of this property, saponins disrupt epithelial function and create other digestive issues.  Saponins have also been connected to damaging red blood cells, inhibiting enzymes and interfering with thyroid function. [4]   

WHICH FOODS? Soy beans, chick peas, oats and quinoa.  We've recently learned that quinoa has particularly high levels of saponins, making it a real concern.

CAN SAPONINS BE REMOVED?:  Not really.  Cooking doesn't have much of an impact, nor does sprouting or fermentation. Saponins can be removed via alcohol extraction, but this obviously isn't a practical technique. 

4. Oxalates

WHAT OXALATES DO:  Oxalates interfere with calcium absorption. [5]  Oxalates will also crystalize in tissues if consumed regularly, creating arthritis-like symptoms and even kidney stones.

WHICH FOODS?: Kale. Spinach, chard, other hearty leafy greens.

CAN OXALATES BE REMOVED?:  Cooking will slightly reduce levels of oxalates.  You can also take a calcium/magnesium supplement with these foods.  Calcium and magnesium bind to the oxalates in your stomach and prevent them from being absorbed.

How Worried Should You Be?

What all of these plant toxins have in common is that they only have significant negative impacts if they are allowed to accumulate in the body.

Eating quinoa or beans or kale once a week realistically won't have a negative impact.  Our bodies are pretty good at clearing out toxins, including plant toxins, when given enough time.

If these foods are a regular part of your diet, however, plant toxins can be a major concern.  If you're eating any of the foods listed above more than once or twice a week, it would be wise to find substitute that doesn't have plant toxin issues.

Which Foods Are The Most Problematic?

Soy appears all over the list above.  If the phytoestrogen and mold-toxin issues weren't enough, the high levels of plant-toxins in soy should be enough to convince you to remove it from your diet.

Quinoa appears to be a particularly potent source of saponins, so consuming it with any regularity puts you at risk for gastrointestinal issues.

Grains, beans and legumes also appear all over the list.  With grains, plant toxins are perhaps the least of your worries, as mold contamination is realistically a much bigger issue.

"Cycling" Greens

If you're a kale addict (I'm certainly one), and the idea of cutting back on kale sounds like torture, don't panic.  In addition to taking a calcium supplement with your kale, you can also "cycle" your greens to avoid accumulation of oxalates.

Taking 5-7 consecutive days out of the month to remove kale (or spinach, chard, etc) from your diet and replace it with another oxalate-free green will allow your body to clear out any oxalates that have accumulated.  Lettuce, arugula and other "mixed greens" are good low-oxalate or oxalate-free greens.


[1] http://www.ncbi.nlm.nih.gov/pubmed/24531910

[2] http://www.ncbi.nlm.nih.gov/pubmed/24499152

[3] http://www.ncbi.nlm.nih.gov/pubmed/19021580

[4] http://www.ncbi.nlm.nih.gov/pubmed/24134011

[5] http://ajcn.nutrition.org/content/50/4/830.abstract


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Can Sitting In A Sauna Raise Human Growth Hormone (hGH) Levels?

Share this post TFUPM Posted March 31, 2014

Saunas have long been valued in societies around the world for ability to detoxify the body and promote vitality.  Recently, however, research seems to indicate that the benefits of time spent in a sauna might go even deeper.  

Powerful Detoxifier

The ways by which a sauna promotes detoxification are relatively straightforward.  Perspiration is a major pathway by which the body excretes toxins, so sweating as much as you do in a sauna is naturally going to improve detoxification.

High temperatures found in a sauna also cause increased blood-flow into tissues via vasodilation, which also aid your body in flushing out and neutralizing toxins that sit stagnant in skeletal muscles and other tissues.  This effect is amplified when a sauna session is interrupted by a cold plunge, which has the opposite (vasoconstricting) effect.  The result is blood moving dramatically in and out of tissues throughout the body and flushing out toxins in the process.

Recent studies have shown that saunas can also promote another mechanism of detoxification.  The unique stress the body experiences in the heat of a sauna has been shown to raise levels of several of the body's endogenous detoxification enzymes, including catalase (CAT) and superoxide dismutase (SOD). [1]

Human Growth Hormone (hGH): Our Body's Vitality Hormone

First, let’s look at what hGH is and why it's important in the body.   hGH is a peptide hormone that sits at the top of a long cascade of hormones related to growth, cell reproduction and cellular regeneration.  

hGH is produced and regulated by the pituitary gland but generally does not act directly on other tissues in the body.  Rather, hGH triggers the release of secondary growth-related hormones (such as IGF-1 from the liver) that account for the majority of the significant effects seen when hGH levels are elevated.

During childhood and adolescence, hGH plays a central role the growth of our bodies and brains.  Later in life, the role of hGH becomes one of maintaining youthfulness and vitality.

hGH is also famously the hormone responsible for catalyzing muscle growth in adults, which is why it has long been popular with athletes and body-builders - and has been on the banned substances list of the regulatory bodies for most sports since the early 2000's.

Largely owing to the regenerative processes triggered by hGH, nearly everyone stands to benefit from maintaining healthy circulating levels of hGH.  If circulating levels can be raised naturally, if even just temporarily, this would also confer benefits and be of interest.

Sauna Treatment And hGH

It's widely known among biochemists and exercise physiologists that certain types of exercise can raise circulating human growth hormone levels.  What's less widely known is that sitting in the sauna can have a comparable effect under certain conditions.

The initial study that revealed the sauna-hGH correlation is actually quite old.  A Finnish team published a paper in 1976 that looked at hGH levels in 55 healthy individuals before and after a sauna session.  It found that hGH levels were on average 140% higher immediately following a sauna session than they were before the session.  hGH levels returned to normal levels after an hour for most participants, but the temporary spike was large enough to make the findings significant. [2]  

Scattered studies over the following 30 years used slightly different experiment protocols and participant demographics, and all found similar elevations in circulating hGH levels following a sauna treatment.  

Maximizing The hGH Response

The unique experiment protocols from the different studies over the years have given us some insights as to how to maximize the magnitude of the hGH release from a sauna session.

First, it's important to note that hGH levels tend to drop off significantly for most people around the age of 50.  Given this, it doesn't come as much of a surprise that a study in the mid 1980’s found little to no elevation of circulating hGH in men ages 49-66 when given the same sauna treatment that produced significant elevations in hGH in men ages 31-46.  [3]

The trick to maximizing hGH response seems to be subjecting the body to exactly the right amount of heat-induced stress.  The temperature, duration and frequency of the sauna session all influence this calculation.

Several studies have shown that the body will adapt to the stress of the sauna when it's used every day.  For this reason, the effect on hGH levels diminishes significantly after three consecutive days of sauna treatment. [4]  The studies that showed the greatest continued hGH response followed a format of sauna treatments every second day.  

The duration of a sauna treatment had significant bearing on the magnitude of the hGH response, as did the presence of a break in the session.  Most studies showed that session durations of ~30 minutes produced the greatest elevation in circulating hGH levels.  

A 2007 study used both 30 minute continuous sessions and 45 minute sessions 5-minute break at the midpoint.  The participants in the first group (30 continuous minutes) showed much greater elevations in hGH levels. [5]

Temperatures used in most studies were around 80 degrees Celsius (176F) with humidity generally around 5-20%.  No study as yet has tracked the relationship between session duration and temperature and magnitude of hGH elevation.  However, as higher temperatures will create greater stress in the body, it's reasonable to expect that the duration required to produce the same effect would go down as temperature increases.


I'm sure it will have occurred to some of you - sauna-induced elevation of hGH could be quite beneficial for athletes and others who train intensely (who's bodies are actively rebuilding muscle and recovering).

There is a period of around 30-60 minutes immediately following a workout when your body will be doing the most active rebuilding of muscle and replenishing of glycogen (the muscles' energy storage).  This is why it's so critical to give your body the exact nutrition it needs as soon as possible after a workout.

Raising circulating hGH during this window can potentially further bolster the already-heightened rebuilding and repairing your body is doing in this window.  This support of your body's rebuilding efforts will translate to greater gains in muscle and fitness, as well as being less sore the following days.

If you're lucky enough to have access to a sauna after your workouts, taking 30 minutes or so to support your body's rebuilding efforts is probably a good idea.  

Of course, the benefits of raising circulating hGH levels are hardly limited to athletes.  As I mentioned above, hGH has a regenerative effect on nearly every tissue, muscle and organ in the body.  For this reason, regular sauna sessions is a tremendously powerful practice for maintaining a youthful body and appearance.


[1] http://www.ncbi.nlm.nih.gov/pubmed/24304490

[2] http://www.ncbi.nlm.nih.gov/pubmed/999213

[3] http://www.researchgate.net/publication/20038119_Heat_exposure_elevates_plasma_immunoreactive_growth_hormone-releasing_hormone_levels_in_man

[4] http://www.researchgate.net/publication/19372559_Endocrine_effects_of_repeated_sauna_bathing

[5] http://journals.indexcopernicus.com/abstract.php?icid=890538



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