November 17, 2009 8:39 PM   Subscribe

Anti-nutrients: Do they pose any legitimate risks?

I'm reading about the Paleo diet, I've noticed some references to the toxicity of grains, legumes, potatoes, etc... Is there any substance to these concerns in a modern diet that contains a large portion of these foods? Are the Paleo folks taking a legitimate term and taking it to mean something more alarmist?
posted by leotrotsky to Food & Drink (15 answers total) 5 users marked this as a favorite

If potatoes are so unhealthy why did so many Irish die during the potato famine?
posted by dfriedman at 8:45 PM on November 17, 2009 [1 favorite]


Presumably a food can still be bad for you even if you starve in its absence.
posted by leotrotsky at 8:56 PM on November 17, 2009 [2 favorites]

Cereal foods aren't toxic, and you'll be hard pressed to find any reasoned evidence to back up this weird claim. Both the National Health Service of England and American Dietetic Association consider the paleo diet bunk, and they're not in the business of colluding to hide toxicity facts.
posted by ellF at 9:04 PM on November 17, 2009

You want to read up on the work of Weston A. Price, and come to your own conclusions. In an online forum such as this one, you won't get any definitive answers - the carbivores will cry "pseudoscience" and the paleo/low-carbers will go the alarmist route.
posted by chez shoes at 9:42 PM on November 17, 2009 [2 favorites]

Incidentally the paleo diet will work for weight loss, because if you exclude all the food that humans have domesticated for high caloric density then you will inevitably be eating very low density foods.
posted by atrazine at 10:31 PM on November 17, 2009 [2 favorites]

A quick scan of PubMed reveals very few "antinutrient" studies, the majority of which are assessing GMO crops. If toxins in grains, legumes, and tubers was such a large problem, surely there would be data correlating the consumption of these foods with increased morbidity due to their effects? Of course, it's possible that such studies have simply not been done, but the more likely scenario is that the nutritional benefit of such foods outweighs the detrimental effects of antinutrients.

It's not all that helpful to think of foods only in terms of their micro-nutrients; it's evident that there's a certain amount of synergy between compounds and the benefit may be lost when isolating one element from the other (see fiber supplementation studies).

Well I heartily endorse drawing one's own conclusions, Weston Price appears to be a dubious source, at best, and should be approached with a healthy dose of skepticism. From Quackwatch: "Price knew that when primitive people were exposed to "modern" civilization they developed dental trouble and higher rates of various diseases, but he failed to realize why. Most were used to "feast or famine" eating. When large amounts of sweets were suddenly made available, they overindulged. Ignorant of the value of balancing their diets, they also ingested too much fatty and salty food. Their problems were not caused by eating "civilized" food but by abusing it. In addition to dietary excesses, the increased disease rates were due to: (a) exposure to unfamiliar germs, to which they were not resistant; (b) the drastic change in their way of life as they gave up strenuous physical activities such as hunting; and (c) alcohol abuse."
posted by eiramazile at 11:04 PM on November 17, 2009 [6 favorites]

Well, legumes have substances such as lectins, and grains have phytates that inhibit mineral absorbtion, and spinach has oxalates in significant quantities, and yadda yadda for any plant you can think of, but traditional techniques of cooking and fermentation usually deal with these problems.
posted by i_am_joe's_spleen at 12:14 AM on November 18, 2009

Antinutrients are a huge crock of crap. Everything is toxic if you eat enough of it, and many foods are toxic or indigestible if you a) don't cook/prepare it properly b) eat the wrong part, c) at the wrong time. If you already have a deficiency, huge quantities of certain foods will exacerbate that - just like eating 3kgs of tomatoes every day could give you problems with gout (it's the acid).

Potatoes, fyi are almost nutriotionally complete. Green ones can cause you some probs, but that's a different kettle of fish...
posted by smoke at 3:23 AM on November 18, 2009 [2 favorites]

Didn't one of the native american cultures die out because they failed to process corn properly?

If grains and fiber can sop up cholesterol, why can't they sop up other things?

Dr. Kellog was a nut, but there must have been some basis for his pro-grain and pro-clean living wackyness.
posted by gjc at 5:26 AM on November 18, 2009

You don't have to be on a "paleo" diet to believe anti-nutrients can be a problem. Traditional cultures often fermented grains and legumes to make them more digestible. They became more digestible not just because the structure of the culturing medium was broken down, but also because the fermentation process reduced anti-nutrients, allowing them to utilize more of the proteins in the plant.

Soaking and cooking for a long time can also reduce anti-nutrients.

You can totally be a carbivore on a reduced ant- nutrient diet. Miso, tempeh, sourdough bread, and dosas for example are fermented!

If you have digestive issues, I think they are best avoided. From the Paleo Diet Newsletter

Dietary saponins from potatoes, beans, and legumes induce a leaky gut,6, 7 as do dietary lectins, alcohol, and NSAIDS. Lectins survive cooking and processing, as well as digestive enzymatic degradation, so they arrive in circulation intact in physiological concentrations to activate the immune system. Lectins are also able to increase E. coli and gram-negative bacteria overgrowth in the intestinal lumen.8

6. Gee JM, Wal JM, Miller K, et al. Effect of saponin on the transmucosal passage of beta-lactoglobulin across the proximal small intestine of normal and beta-lactoglobulin-sensitised rats. Toxicology 1997;117(2-3):219-28.

7. Keukens EA, de Vrije T, van den Boom C, et al. Molecular basis of glycoalkaloid induced membrane disruption. Biochimica et biophysica acta 1995;1240(2):216-28.

8. Cordain L, Toohey L, Smith MJ, Hickey MS. Modulation of immune function by dietary lectins in rheumatoid arthritis. The British journal of nutrition 2000;83(3):207-17.

I find the Quackwatch paragraph amusing because who doesn't abuse crap foods? It's kind of patronizing to say they did it because they are ignorant. I ate whole bags of reeses cups for dinner while I was studying for Food Science tests. Crap is addictive and it does cause malnutrion as it almost always displaces food with actual nutrients.

posted by melissam at 6:03 AM on November 18, 2009 [3 favorites]

Have you looked into the concept or hormesis? Meaning that taking small amounts of a toxin helps teach your body to prepare for larger amounts? I'm not advocating taking poison! But the slight amounts of toxins that are naturally present in many foods are actually good for you. They stimulate stress response pathways in your cells. (But everything in moderation, right?)

Most plants have got some low levels of toxins, evolutionary adaptations to keep themselves from being completely* devoured. The exception, I think, is fruit. Fruit is meant to be eaten so that the seeds (themselves having toxins) can be spread about - ideally excreted in a pile of fertilizer, so to speak - and that helps the tree reproduce.

*Completely, meaning the whole population in a given area.
posted by Knowyournuts at 10:09 AM on November 18, 2009

Oh and - how timely, this post from one of my favorite medical researchers just came through my feed reader.
posted by chez shoes at 10:21 AM on November 18, 2009 [3 favorites]

Sounds like you've been reading Richard over at free the animal. He's a bit overzealous about terms like "anti nutrients".

This is not pseudoscience, the paleo crowd usually discusses topics like this in terms of actual research eg. read this paper, or glance at tables 4 and 5:
Minerals, trace elements, and potential hazards

Stephan over at whole health source has several posts on this topic:
- How to Eat Grains
- Dietary Fiber and Mineral Availability
- A few thoughts on Minerals, Milling, Grains and Tubers

Wheat also may play a role in many diseases. Nephropal has an interesting post on schizophrenia and gluten.

This also is not just limited to particular anti-toxins, but how different dietary habits affect the gastro-intestinal tract, including gut bacteria.

This post from whole health source outlines some types of food that increase hydrogen gas production in the gut, which in turn feeds H. pylori bacteria (which everyone is infected with, references provided in article). H. pylori secrets urease, which produces bicarbonate a few steps later, reducing stomach acidity, which reduces nutrient absorption.

Digging deeper, Molecular biologist Art Ayers explains how carbohydrates, H. pylori, K. pneumonia and gut biofilms interact in this post at cooling inflammation.

The NHS of England and ADA consider paleo bunk as they both still support the idea that saturated fat is bad, low fat diets are good.

Again, Stephan and whole health source lays the ground work discussing saturated fat, MRFIT, Anti-Coronary Club trial, Lyon Diet-Heart Study and the Women's health initiative dietary modification trial.

Dr. B G has a five part series on the benefits of high saturated fat diets: part 1, part 2, part 3, part 4 and part 5.
posted by zentrification at 1:55 PM on November 18, 2009 [3 favorites]

Dr. Kellog was a nut, but there must have been some basis for his pro-grain and pro-clean living wackyness.

No. The stopped clock is right twice a day, and eating more fruits and vegetables and whole grains were probably a net benefit for people who ate tons of cured meat and pie (which were staples of the middle-class US diet in the 19th century), but Kellogg was just pulling stuff out of his ass.

Literally--he advocated daily enemas.
posted by Sidhedevil at 3:59 PM on November 18, 2009

chez shoes, Jenny, is not a medical researcher any more than I am. She is just a person without a degree in science who has diabetes and who reads medical research. Some of the people she "debunks," like Stephen from Whole Health Source or Kurt from Panu have Phds in science. But she doesn't really reference them...just straw men from commenters.
posted by melissam at 4:13 PM on November 19, 2009

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