Recently, some health specialists have expressed concern over the high levels of Oxalic Acid found in some very nutritious foods, (some listed below). Oxalic Acid has been blamed for causing kidney stones. This is because oxalic acid, or oxalates, can interfere with our body’s absorption of calcium.
When calcium is not properly absorbed or assimilated, the excess calcium can actually become toxic and contribute to health conditions like kidney stones. Menopausal women should be more concerned about calcium absorption as their bone density can be compromised. Through research, I found that if you take calcium two hours before or after you consume these foods, you will absorb them safely – if they are the right form. Because of this concern, some have suggested that people cut back on eating foods high in oxalates.
My advice is to do your own research. For example, on healthline.com, Dr. Andrew Weil’s website and others, generally advise against cutting back on foods high in oxalates, not only because these foods provide other essential nutrients, but because cooking them significantly lowers their oxalic acid levels. Also, calcium-rich choices can be consumed along with these foods to counteract any negative effects of the oxalates. Research says to increase your fluid intake by drinking fluoride-free water, not more sodas, which are actually part of the problem. We’re seeing stones in very young children now because of these unhealthy drinks. By substituting water for soda, you don’t have to give up nutritious foods like spinach, sweet potatoes and turnip greens.
In addition, avoid sugar, especially high fructose corn syrup, and non-fermented soy and make sure you get enough magnesium . Dr. Weil suggests women only, who don’t get enough calcium from food, should supplement their diet “with 500 to 700 mg of calcium citrate in two divided doses , taken with meals.” He strongly advises against men taking calcium supplements because of the link between high calcium intake and prostate cancer.
Other doctors and experts feel it’s best that everyone get their calcium from foods and warn that taking supplements can increase the risk of kidney stones. Some calcium supplements can contain heavy metals. Please note, there’s a new evidence of a better calcium supplement that comes from algae, AlgaeCal and is not a carbonate form of calcium, an inferior form that Vivian Goldschmidt of saveourbones.com says is not well-absorbed. Heathline.com adds that the good bacteria in our gut helps break down oxalates, before they can combine to minerals and cause any harm. However, because of antibiotic use or for other reasons, some people don’t have enough good bacteria to protect them from oxalate harm.
For those who feel they need to limit their intake of the following foods, make sure you eat these foods cooked and/or combined with ones rich in calcium:
Foods high in oxalate (100–900 mg per serving)
- Beet greens
- Rhubarb
- Spinach
- Beets
- Swiss chard
- Endive
- Cocoa powder
- Kale
- Sweet potatoes
- Peanuts
- Turnip greens
- Star fruit
Calcium-rich foods that are low in oxalates include:
- Cheese
- Plain yogurt
- Canned fish with bones
- Bok choy
- Broccoli
In conclusion, most of us don’t have a problem with oxalates. There are ways to limit any negative affect they might have, which several experts believe is minimal – if any. Answering an osteoporosis patient’s worries about oxalates in the green smoothies she drinks, health coach Vivian Goldschmidt says the following, which should alleviate a lot of concern over consuming these healthy foods, “While laboratory studies have shown that oxalates may interfere with calcium absorption (it doesn’t actually leech calcium from the bones), the reduction is relatively small and should not prevent you from eating oxalate-rich foods in moderation, such as spinach, which contains many valuable nutrients.”
You can read more about oxalates and how to prevent kidney stones at the following websites:
https://articles.mercola.com/sites/articles/archive/2014/11/19/kidney-stone-prevention.aspx
https://www.drweil.com/diet-nutrition/nutrition/avoid-vegetables-with-oxalic-acid/
https://www.healthline.com/nutrition/oxalate-good-or-bad#section2