Are Your Veggies Poisoned? – By Dr. Alan Christianson
Hi, there! Dr. Alan Christianson here. Are your veggies poisoned? What do I mean by this? There has been a big trend in popular literature, discussing certain foods. A lot of blog posts and experts have talked about things hidden in your food that seem really dangerous. The big dangers you hear about are oxalates, nightshade compounds, phytic acid and goitrogens. Honestly, if you follow all these lists, you would come away with no foods left to eat. So, let’s talk about this.
In general, these compounds are all in a class, called phytotoxins. Sounds pretty scary, right? Here, in the Sonora desert, a lot of our plants have physical defenses – sharp things on them. However, many plants have chemical defenses. These chemical defenses cause other plants not to grow right next to them, fight off fungi and repel insects. What are some of these major chemical defenses? What foods are they in? What are the most important steps you should be taking in your diet? Let’s talk about these things individually.
We are hearing a lot about oxalates. Oxalates are found in a large variety of foods. The argument is when you consume more oxalates, your body generates more oxalic acid. It has been known that some people make too much oxalic acid. About 1-3 people per million have a condition, called hyperoxaluria. That means they generate a lot of oxalic acid (make too much in their urine), which causes a rare type of kidney stone to form. The foods that have been known to raise urinary oxalates include blackberries, beets, spinach, rhubarb, strawberries, a few different types of nuts, chocolates, tea, wheat bran and many types of dry beans and legumes (with the exception of lima beans). It has been debated whether these foods raise urinary oxalate and whether they worsen kidney stones in those who have the genetic condition. The data is pretty strong that even though tea may raise oxalates in the urine, it actually decreases kidney stones, even in those with hyperoxaluria.
There have been theories stating oxalates get into the body, cross into the brain, hurt the joints and cause a variety of symptoms. Not only has there never been solid data correlating that, but there is also not even a strong mechanism or plausible way that would happen. Our body naturally makes the vast majority of oxalates we have and the oxalic acid in our bloodstream. If you have a condition, like arthritis, chronic pain conditions or mood changes, you know there are better days and worse days. If you have high-oxalate food on a day when you’re symptomatic, you could think the food caused that. However, the oxalates are not coming from your diet; you are naturally producing it.
There are a number of apps and lists that show which foods are high in oxalates. The problem is they are not in agreement. If you look through any number of those sources, the lists of foods are inconsistent. There have actually been academic studies done on this. The studies looked at many lists of oxalates – data such as how many milligrams of oxalates are in the listed foods. The consensus among researchers is all these different lists and apps have no real correlation to one another. If you are in the rare subset of people with the genetic condition, hyperoxaluria, you usually get kidney stones early in life before adolescence. This often gets diagnosed because it is a very uncommon type of kidney stone. For these people, there still is a general idea that you are better off avoiding those few, high-oxalate foods, with the exception of tea. For the rest of us, the high-oxalate foods are healthy foods, like beets and blackberries. So, I would not stress too much about this.
Another category that has gotten a lot of attention lately is nightshade foods. They are part of the solanine-type plants, which is a group of plants, called Solanaceae. They include potatoes, tomatoes, eggplants, bell pepper, goji berries and a few other odds and ends. It has been known for some time that portions of the plant have an alkaloid, called solanine. There is no debate that solanine is toxic. For example, if you make a big giant salad from potato plant leaves, that is not a good idea. It could be fatal. The other concern is when these plants are unripe or overripe they can have more solanine. So, if you were to take a lot of sprouting or overripe potatoes with lots of green around the sprouts and eat them, you could get poisoned from that. The last case of solanine poisoning was around 1950 in the United States. So, it is not a common problem.
I grew up in Northern Minnesota, and our house had a root cellar. This was an area in the basement where we kept the root vegetables during the wintertime – potatoes, carrots, rutabagas, squash and parsnips. There was a problem if the area was warm or if the vegetables were too close to things that were heated. They could sprout and start to go bad. In the past, there were isolated cases of people eating too many green potatoes when they had fewer food options. These people were getting poisoned.
Before tomatoes were brought to the new world, it was believed they were poisonous. It is true that the leaves of the tomato plant, like the potato plant, is something you do not want to eat, but we know that tomatoes are not poisonous foods. Even though it was believed that people die from tomatoes, this is not true. I have talked about the lycopene from tomatoes being really good for the health of your eyes. It off-sets macular degeneration. It is also good for maintaining good prostate health and prostate function. Eggplant is another great food. It is rich in some fibers and also some unique B-vitamins.
In the early 1980’s, there was a researcher who theorized that tiny amounts of solanine were the culprit behind arthritis and aggravated it’s symptoms. Based on this theory, there were a large number of studies done. It was argued that some have a lower threshold of sensitivity than others. We’re not sure if that is possible or not. There is a chance that some can be more sensitive or more allergic to solanine, but it has not been documented just yet. We know in cases of actual solanine toxicity, people can get joint pain. In one study, one group of people were placed on diets including potatoes, and another group were not. Their symptoms were monitored to see when they had more joint pain and when they did not. The researchers did not know who was eating the higher solanine diet until after the monitoring was done. When that study was completed, they found there was really no correlation between eating nightshade plants and joint pain.
Another big category I want to talk about is phytic acid or phytates. This theory came up a lot with the Paleo movement. The argument said some foods contain phytic acid and categorized it as both a phytotoxin and an antinutrient. An antinutrient is something that can bind up with nutrients and make them less absorbent. The idea is that certain foods, especially beans, legumes and grains are higher in phytic acid. So, it is said if you eat them, the phytic acid will take away nutrients from your body and also damage your intestinal tract. It has been argued that it can lead to autoimmune disease and other problems. Let’s take a look at this one.
Which foods have phytic acid and which do not? A lot of foods that we call “Paleo foods” have a ton of phytic acid. Green vegetables have it also. Coconut has phytic acid. Coffee has pretty fair amounts of it. Nuts and seeds have good amounts. Even meats and animal protein can have it, based upon the diet of the animal you are eating. So, you really cannot get away from it. Some foods are a bit higher in it than others. Beans and grains are higher than some, but they are not top on the list. Per calorie, greens, nuts and seeds tend to be quite a bit higher in phytic acid then grains and beans.
There is actually a lot of research on phytic acid. If you were to go on medical databases and see what has been studied, there is tons of data about it being cancer protective. It protects you against big cancer types, such as breast, prostate, rectal and lung cancers. The risks for these cancers are all lower in those who have more phytic acid. So, more phytic acid is a good thing. There is a version of phytic acid, called IP6 or inositol hexakisphosphate. This is such a powerful cancer-fighter that it is the subject of many phase II clinical trials. They are actually testing it as a cancer remedy. Not only would I not encourage you to be afraid of phytic acid, but I would encourage you to have it in your diets. There is no data supporting that it has harmful effects on the intestinal tract or causes autoimmunity. There was one argument hypothesizing this could happen, but there are no studies showing this has happened. On the contrary, there are a lot of studies showing it is actually a very good thing for the immune system, such as lowering the risk of cancers.
Let’s look at this antinutrient thing. I almost imagine this being a ninja breaking into your body, grabbing all of your zinc and manganese and running out with it before it gets caught! Not so much though. What happens is this: A food has a certain amount of nutrients. Let’s say you absorb 100 milligrams of magnesium (just making this up) from your beans. If the beans did not have the phytic acid, it is possible that you may absorb 120 milligrams of magnesium. The phytic acid inhibits some of the absorption of it. That does not mean it takes out what you have in your body, but it causes you to absorb less from that food. We have known about and expected that. The phytic acid also does not prevent you from absorbing minerals from other foods in that same meal.
There was a big study done on this mechanism. One of the common minerals we will see with nutrient absorption is zinc. Zinc can be really hard to get into the body. Some populations are at risk for low zinc. One of the biggest is adolescent boys. They need more of it, and their diets may not contain much of it. There was a study done on adolescent boys on diets that were unusually high in phytic acid. It was shown they did not develop zinc deficiency from that. So, this is not a big factor, but theoretically it could be. There have been some cases where people at risk for anemias were a little more anemic when their diets were higher in phytic acid, but honestly, a well-rounded diet can help circumvent that.
The other last class of compounds we have been told to be afraid of is goitrogens. This would include cruciferous vegetables, especially. These are vegetables like broccoli, cauliflower, brussels sprouts, kale and spinach. Soy and millet also get put in this class. If you are in an area with iodine malabsorption (which causes goiters or thyroid enlargements), then a high-goitrogenic diet will make that just a little bit worse.
Let’s wind back the clock and go to upper Michigan in the 1910’s. About that time, around a third of the kids in school had goiters and large necks. If the kids had a diet high in raw, cruciferous vegetables, that ratio might have only increased from 30% to 35% – a very small increase. There is no relevance of goitrogens being bad for your health in the modern world now that we have iodine-fortified salt. The same compounds that are goitrogenic are also cancer-fighters. There is a lot of data proving it is especially good against the hormonal cancers. So, the breast, ovarian and prostate cancers are all at lower risk when you have a higher intake of cruciferous vegetables. They are very good things.
The one goitrogenic food I would question is soy. We have concerns back and forth about its hormonal effects on autoimmune thyroid disease. So, I am not a fan of soy. There are unfermented versions of soy, like textured vegetable protein, soy protein isolates or tofu, which are the most questionable. The fermented versions of soy, such as miso or tempeh or natto, are clearly not dangerous. I had some of this a few days ago with my daughter, as we wanted to try it. Natto is pretty intense stuff. It is a fermented paste with some chunks of soy. It is ridiculously healthy. It is very high in vitamin K2, which is a powerful thing from keeping your body from calcifying. It is also very good for the immune system and the intestinal tract, but you do have to acquire a taste for it. Other goitrogens are actually really good foods and healthy for you.
So, why are we told to fear so many different foods, and what is the relevance of this to our health? I think there are a lot of things we are justified in avoiding. I do not know that fear is the best response, but there is validity to avoiding and limiting certain foods in our diets. I would put all the weird, processed foods on that list and sugar on the top of that list. So, we have got enough to worry about there. Let’s not add unnecessary fear of foods that are naturally occurring.
If we could rewind 100 years and look at the foods our grandparents had access to, we would find they are not dangerous foods. No one has wrecked their health because they did not know to avoid blackberries, beets or broccoli. Quite the opposite is true, and these are wonder foods. The exact same compounds that are planned defenses are things that help our bodies. Planned defenses are specific, so you really want a variety. You would not want just one type of food forever. Let’s say you were really still concerned and wanted to avoid all these phytotoxins. Well you cannot eat plants. You cannot eat legumes. You cannot eat nuts and seeds because everything in that category has phytotoxins. Also, animals have it because our animals eat plants. They end up with a number of these phytotoxins in their bodies and in their meat. So what you would be left to eat would be purely synthetic, processed, isolated foods. Twinkies are pretty low in phytotoxins. I would not advise those. The only way to be off phytotoxins is to be off natural foods. That is a bad thing. So much data shows that having a variety of non-processed foods serves us well.
As a closing point, I want to give a teaser for a future topic. How is it that someone could eat a food that is medically safe but have symptoms afterwards? There is something, called the nocebo effect. It is very real and powerful. We will talk more about this in a future topic. I am going to teach you how to avoid that and have greater tolerance of more good foods.
Thanks for tuning in. Dr. Christianson signing out. I will see you all real soon.