I could reveal my age, but a popular comic book hero growing up, Popeye ate spinach to build muscle. They always urged us to “eat our spinach and be like Popeye”.
Unfortunately, the spinach that was mostly available back then was the nasty, overcooked variety that came in a can. It wasn’t until my family started growing spinach in our own garden that I learned to love the tender, sweet, freshly cut leaves in a salad or lightly fry them with lemon and butter. Its delicate texture and mild taste make it a favorite side dish for smoothies, soups, and stir-fries. Americans today consume nearly 2½ pounds of spinach a year per head, according to the USDA.
Spinach is a dark green leafy vegetable that is rich in nutrients, high in niacin and other B vitamins, vitamins A, C, E, K, high in calcium, iron, magnesium, phosphorus, potassium, copper, and manganese.
Spinach also contains serious antioxidants that fight free radicals that damage the cells in your body and help prevent cancer, chronic diseases, aging, and other serious health problems. The folic acid it contains, an essential B vitamin, is particularly important for pregnant women and their fetuses and also protects their cardiovascular system, combined with magnesium, which essentially supports all body functions as well as the maintenance of healthy blood pressure. Spinach is also a great food for the brain and improves memory and mental clarity.
Spinach belongs to the same family as beets and Swiss chard. These superfoods are known to reduce inflammation and slow down the aging process. No wonder spinach looks like a superstar.
Spinach’s high content in antioxidants, which include beta-carotene, lutein, and zeaxanthin, helps fight cancer, heart disease, diabetes, and obesity. Spinach protects immunity by reducing inflammatory responses, reducing cell damage, and promoting digestive health.
It should also be noted that spinach contains a healthy natural type of steroid that increases sugar/glucose metabolism and helps maintain healthy blood sugar levels. This, of course, is especially beneficial for people with prediabetes or diabetes as it helps eliminate insulin needs.
So yes, spinach has some very surprising health benefits, but it can have downsides too.
Although spinach is high in iron and calcium, these nutrients from spinach are difficult to absorb. And while there is a lot of calcium, it is practically useless in our bodies because spinach contains one of the less bioavailable forms of calcium.
This is in part because spinach contains substances that inhibit the proper absorption of certain nutrients. Spinach also contains a substance called oxalic acid, or oxalates, which can bind calcium and iron in the body and prevent the body from absorbing them. Oxalic acid is a substance found naturally in a number of plant foods, including rhubarb (its leaves are high in oxalic acid), chard, and beet leaves.
Oxalic acid binds to certain minerals so that the body cannot absorb them. So if you consume large amounts of foods high in oxalic acid on a daily basis, you may experience nutritional deficiencies over time. However, we’re talking weeks to months, not just a meal or two. . . .
In some people, the high levels of oxalate in spinach can also put them at increased risk of kidney stones and joint problems.
Oxalates can build up in the body, especially in the kidneys. When oxalates combine with calcium, kidney stones can form. Calcium oxalate is actually responsible for around 80% of kidney stones. And this is where spinach gets its bad reputation.
Oxalates are not recommended for people with inflammatory conditions like gout, arthritis, and even vulvodynia. These people tend to have higher levels of oxalate and calcium absorption. But for most of us, this shouldn’t be a problem as long as you don’t eat spinach every day.
In fact, gut bacteria are believed to play an important role in the absorption of oxalate, as certain types of gut bacteria break down oxalate, particularly Oxalobacter formigenes, lactobacilli, and bifidobacteria. Other research has shown that oxalate absorption is related to the combination of foods consumed during a meal. For example, even if your body has problems absorbing calcium from spinach when it is eaten with other calcium-rich foods like milk or cheese, calcium from other foods will be absorbed easily.
Cooking spinach was thought to reduce oxalate levels, but research shows that it does very little to reduce oxalates.
In general, unhealthy oxalate buildup is a rare problem with spinach and other oxalate-rich foods. So there is no reason to avoid spinach unless your doctor tells you to. or if you have gout or arthritis as mentioned above.
In general, spinach can be a healthy addition to most people’s diets, but be careful not to overdo it to avoid consuming excess oxalates on a daily basis. So pour a handful of smoothies, have a healthy spinach salad for lunch, and maybe even try a spinach cream for dinner. But for many people, it may be better to eat spinach several times a week than every day.