Several months ago I attended the Weston Price Foundation annual conference and spent a very interesting day on the learning tract entitled “plant toxins”. While we are not exactly dealing with Audrey II the man eating plant of the Little Shop of Horrors, there is definitely some very important and useful information to understand about naturally occurring chemicals in plants that may be toxic to some people. Think about it – a plant is a living being and just like you and I, wants to survive. Therefore, it has some built in mechanisms to do so.

Nature has placed a variety of anti-nutritional factors and toxins in grains, nuts, seeds and beans for a variety of reasons. Let’s take a look at a few of them.

Phytates are found in beans, grains, and seeds. Their primary function is to prevent premature sprouting. Ever wonder why we’ve found seeds that are thousands of years old, still intact, and able to grow plants from them? That’s why – the phytates have protected them from being “digested” and maturing. However, when we eat them, phytates that are still intact block proper absorption of many minerals, including zinc, calcium, and iron. So – while we are told that whole grains, nuts and seeds contain many valuable vitamins and minerals – our ability to digest and assimilate them is greatly diminished if the phytates are still present. This is why sprouting and fermentation are promoted to deactivate the phytates so the nutrients are available. And, this is why I encourage my clients to eat sprouted breads and fermented vegetables.

Protease inhibitors disrupt our ability to utilize the enzymes that help us digest protein. An example is trypsin, found in soybeans, other beans, grains, nuts, seeds, vegetables of the nightshade family (more about them later) and other fruits and vegetables. In most cases trypsin is neutralized by cooking, however not in the case of the soybean. So – while we are told that soy is an excellent source of protein – the actual truth is that it is difficult to digest and when mixed with other proteins (“protein shakes” or “health bars”) it is also inhibiting the digestion of those proteins. As I like to say, “It is not what happens in a test tube, but what happens in your body.” This is only one of the reasons why soy is not a health food despite what the food manufacturers tell you!

Back to the nightshade family. This includes white potatoes, tomatoes, peppers, and eggplant. These foods have been linked to muscle pain and tightness, morning stiffness, poor healing, arthritis, insomnia, heart burn and gall bladder problems. Many people have eliminated the above symptoms by removing nightshades from their diet. The reason behind this – nightshades contain calcitriol, the most active form of Vitamin D. To make a long story short, calcitriol signals the intestines to absorb calcium from the diet. If we have too much it leads to high blood calcium. The quick and easy solution for the body is to store the extra calcium in the soft tissues. Overtime these deposits build up, a condition known as calcinosis. Rather than your joints wearing out (the common view of osteoarthritis) perhaps the truth is that the cartilage is being slowly calcified?

One last plant toxin – oxalates – the salt form of oxalic acid. Again, I’ll get right to the point. Oxalates inhibit the absorption of calcium and represent about 80% of all kidney stone issues. Oxalates are found in a variety of plant foods, but the highest sources are in soy protein, spinach, peppercorns, and peanuts. Please note that cooking does not destroy oxalates, although they will reduce them slightly. This is another reason to avoid soy and why I recommend that spinach be cooked and not consumed as a large salad. One of the doctors at the conference told the story of another doctor who decided to eat healthy. Part of his plan was to have a large spinach salad every day for lunch. Within two months, he had developed severe kidney stones!

So where am I going with all of this? We are all individuals and all react differently to food. However, there are times when we think we are eating healthy foods, yet still seem to have discomfort, gas, indigestion, or a variety of other symptoms. It is at those times when we need to look really closely to see if there is something in the diet that is at the root cause.

Bernard Rosen, PhD is a Nutrition Consultant and Educator. He works with individuals, groups, and at corporations to create individualized nutrition and wellness programs. His office is in Thiensville, WI. To learn more or to schedule an appointment, e-mail at, call (262) 389-9907 or go to