Photo of a Strawberry Hedgehog in bloom.
Using cactus while in the desert can have adverse effects on the human body. I have found a relation between eating cactus and the lowering of the core body temperature, as it has happened to myself. The reason this happens is because of toxins that are present in all cactus, regardless if they are considered edible or not. I have found that most if not all have various amounts of calcium oxalate crystals which will have two effects on the body. These are kidney stones and the reduction of core temp. Kidney stones usually come from the build up of these crystals in the kidneys. Under normal conditions being well hydrated and being able to flush the body will aid in reducing this likelihood. While most of us walk around dehydrated, this can speed the development of kidney stones.
One of the ways I have looked at useful or so called “edible” cactus while in the field is as a refrigerant. This means that the benefit of having the ability to lower your core temperature can in fact aid in the prevention of heat stroke. In the past I have ran an experiment using prickly pear cactus and hedgehog cactus in the heat of summer. I also repeated this later in the fall and into winter. I found that I was a lot more comfortable in the extreme heat. This was because of the effects the plant was having on my body. I found that when the temperatures lowered I began to get chills and that it was very difficult to warm up. To make things worse, when I had eaten these in abundance these chills were accompanied by body aches. This condition can directly cause hypothermia, a potentially fatal condition. While some cultures make the nopal or prickly pear part of their diets, this is a more domesticated version of the cactus. The compounds that cause these issues are less in these particular plants. Also keep in mind that calcium oxalate crystals are not necessarily destroyed let alone lessened during the cooking process.
One of the biggest questions I get asked about is the Barrel Cactus. Does it in fact hold water? The answer is yes, but there a few things you need to know about this cactus beforehand. Personally, the only time I have used the barrel cactus was during the hottest part of the summer, when the monsoon rains have started moving across the desert (This was done by purchasing a native cactus from a nursery). The reason for this is because of the compounds found in this plant. As the cactus uses its water stores, these compounds can actually become more concentrated. You can access the inner juice by cutting off the top of the cactus but keep in mind this will destroy the cactus and they are a highly protected species. This juice is contained in a spongy material that really can be wrung out into a container or by using your thumb as a spout. The drawbacks of this liquid are as mentioned earlier the lowing of the body’s core temperature. Also the liquid is very thirst provoking. This will keep you alive but, keep in mind the issues that can come from using these types of plants.
Another way I have come into contact with the juice of a cactus is while pasteurizing water. This may sound a little strange; however in knife only or no knife classes I have held in the past we used prickly pear pads to pasteurize our drinking water. This is done by harvesting a large pad, don’t be stingy these things are very abundant, cut off the base of the pad and open it like a canteen. I will then place a round stone into the opening to hold it open and add my water. You will then place this next to the fire to slowly heat up for an extended period of time. The prickly plant compounds will mix with the water when consumed. At the same time we are able to keep hydrated and help our body flush the oxalate crystals out of our kidneys. Needless to say, this method is not used during the colder months.
I have also used a prickly pear and a hedgehog cactus to clear drinking water. I will simply cut a section out of the plant and scrape it gently till the juice is flowing. This will then be added to the bottom of a found container. As the water settles this viscous material in the cactus will hold the sediment in place allowing you to carefully pour into a secondary container or drink directly from the one in use.
When using cactus in the field don’t let this article scare you. Understand that these plants have uses and can be utilized by being educated and understanding how and when they are in fact safe. Also when thinking of primitive cultures, yes they did utilize these plants as part of their everyday life. By researching and learning about climates and the terrain of that time I have found that there was a lot more water here then. This is long before we came along and damned up all the rivers. That being said I am sure they had plenty of water to offset some of the effects of the oxalate crystals. I also strongly believe that they knew exactly how to utilize the plants in every way possible. Today however, we have moved away from this way of life and our bodies are not adapted to their use. Their bodies could well have had a natural tolerance to some of the toxins as well. With the understanding that not only are our bodies different, but our metabolisms are as well. This has a big effect on us when it comes to using some plants.
A little off subject, just merely living in the desert will have its own set of health issues that come with it. For one, most water that we use in our homes and gather in the field is VERY hard. This means there is a very high amount of dissolved minerals. These minerals can and will get into our kidneys and cause kidney stones to form. Some of these are in the form of arsenic which leaches from some stone naturally, as well as heavy metals and other toxins caused by septic tanks and mine run off. Secondly I am doing some research on this one, a lot of the sand that blows around is mixed in with the dust of many different minerals such as silica and mica. When this enters our bodies by way of breathing, over a long period of time can cause silicosis. This really brought on something to ponder when it comes to spending a lot of time in the field being exposed to these types of things.