Is Spinach Good For You?

In recent years Spinach has been touted as a superfood. It has been claimed it  helps fight cancer and metabolic syndrome, and that it’s good for your mood, your brain, and your eyes. Apparently it also makes you strong like Popeye :)

But critics tell us that spinach absorbs a lot of pesticides, and that it’s high in oxalates, which are an anti-nutrient that keeps most of the minerals in spinach  being absorbed by your body.

Well the facts are there some truths in each of these views, so let's delve a little deeper;

Health Benefits of Spinach

The nutrients and potent plant compounds in spinach make it one of the healthiest foods on the planet. Below are some of the known health benefits of making spinach a regular part of your diet.

1. May have anticancer effects

Some epidemiological studies have observed a protective role of spinach consumption when it comes to cancers of the breast, colon, and esophagus. In one study, which included 6,888 cases and 9,428 controls, women who ate at least two servings of spinach per week had a 45% lower risk for breast cancer. (Carrots had the same effect, in case you prefer orange to green.) Some of the anticancer effects of spinach may come from its lutein content, a type of carotenoid that provides a yellow pigment to plants.

In case you’re wondering why spinach isn’t yellow, consider this lesson from Kindergarten: Yellow and blue combine to make green. Which does make me wonder — if spinach didn’t have so much lutein, would it be blue? We may never know. But what we do know is that regular inclusion of spinach in your diet may be cancer-preventive.

2. May improve metabolic syndrome

Metabolic syndrome refers to a cluster of conditions that raise your risk for chronic diseases like heart disease, cancer, and type 2 diabetes. Some of these conditions include high blood pressure and blood lipids, abdominal obesity, and poor blood sugar management. Eating spinach may help prevent some or all of these conditions.

A combination of regularly consuming spinach and practicing aerobic exercise was observed to offer the best improvement in metabolic syndrome markers in one animal study.

In another animal study, spinach consumption improved insulin resistance, high cholesterol, high triglycerides, and endothelial function. Some of this benefit may come from the dietary nitrates found in spinach. Nitrates convert to nitric oxide in the body which is a gas that dilates arteries and improves circulation which in turn improves heart health.

And in a 2021 case-control study published in the journal BMC Gastroenterology, researchers analyzed 225 patients who had been diagnosed with non-alcoholic fatty liver disease (NAFLD), a condition closely linked with metabolic syndrome, and 450 controls. Researchers found a significant inverse correlation between the consumption of spinach and rates of NAFLD. The more spinach (including both raw and cooked) that the study participants ate, the lower their odds of suffering from NAFLD.

3. May help boost your mood

Some people may find that consuming spinach makes them happy. One telltale sign is declaring loudly, publicly, and repeatedly, “I yam what I yam.” It’s not just in their heads, though; there’s solid scientific evidence that spinach is good for our brains and may actually help boost mood.

In one 2018 study, researchers examined the mental health effects of eating raw versus cooked or canned fruits and vegetables on young adults. They found that eating raw, unprocessed produce predicted significantly better mental health outcomes compared to cooked or canned produce. Spinach was among their top 10 fruits and veggies, which were most strongly related to mental health.

Another 2018 study among mice went as far as to suggest that spinach specifically offers anti-stress and antidepressant properties. The researchers observed that frozen spinach powder extract increased glutamate and glutamine levels in the prefrontal cortex of the brain. Low levels of these two compounds often appear among people with depression.

4. May be good for your brain

In addition to boosting your mood, eating spinach and other leafy greens may have other beneficial effects on your brain.

In a 2018 study published in Neurology, researchers found that green leafy vegetables (including spinach, kale, collards, and lettuce) were positively — and significantly — associated with slower cognitive decline in dementia-free older adults (average age of 81). Even better, these benefits appeared with just one single serving of leafy greens per day. But what’s most impressive? The rate of cognitive decline among those who consumed the most greens, compared to those who consumed the least, was the equivalent of being 11 years younger.

5. May increase your strength and athletic performance

Spinach contains a phytosteroid called ecdysterone, which may be responsible for some of its strength benefits. In a 2019 comparative study, researchers concluded that the performance effects of this naturally occurring steroid hormone were so significant that ecdysterone could warrant an addition to the list of prohibited substances for sports, along with other anabolic agents. Good thing that Popeye lyricist Sammy Lerner didn’t know this — “I’m strong to the finich ‘cause I get my ecdysterone” just isn’t as catchy as the original.

The nitrates found in spinach may offer other strength benefits, too. A Swedish study found that adding nitrate to the drinking water of mice for one week resulted in much stronger muscles, compared to those of mice that didn’t get nitrates.

6. May help support eye health

Spinach contains the antioxidant-rich carotenoids lutein and zeaxanthin. These compounds provide pigment to plants and are also responsible for many of their health benefits, particularly to your eyes. Lutein and zeaxanthin have been extensively studied for their association with a reduced risk for cataracts and age-related macular degeneration, a condition that may, over time, result in blurred eyesight or blindness.

According to a 2016 pilot study, consistent intake of lutein-rich spinach increased macular pigment optical density, visual acuity, and blood levels of lutein. The 11 healthy participants consumed 75 grams (approximately ⅓ cup) of frozen spinach containing 10 mg of lutein every day for 2 months.

Potential Spinach Health Risks

Despite its numerous health benefits, spinach does also come with a few potential downsides to consider. While some populations may want to avoid large amounts of spinach in their diet, for most people its benefits far outweigh its risks, which are discussed below.

Contains Oxalates

First, spinach contains oxalates. Oxalates, or oxalic acid, bind to minerals like iron and calcium, making them less bioavailable for your body to use.

And spinach does contain a higher concentration of oxalates than most other plant foods. Just a half-cup of cooked spinach contains around 755 mg of oxalic acid, though most of this is excreted from your body through urine.

While oxalic acid doesn’t pose a risk for most people at the levels in which they’re normally consumed, there are some concerns that they may increase the risk of kidney stones in people prone to them. Healthcare providers will sometimes prescribe a low-oxalate diet to people with this susceptibility. Adhering to such a diet generally means eating less than 100 mg of oxalic acid per day, which means no spinach (or beet greens or Swiss chard). When this diet is prescribed, it’s usually out of an abundance of caution because the role of dietary oxalates and kidney stone formation is inconclusive.

Oxalates may also pose concerns for people who have a history of frequent antibiotic use. This is because some of the oxalates you eat are broken down by bacteria in the gut. But some people may lack those bacteria due to antibiotic overuse, and therefore may benefit from a lower-oxalate diet.

However, oxalates are not evil. In fact, they are present in almost every food we eat, to some degree. But some foods like peanuts, rhubarb, spinach, beets, Swiss chard, chocolate, and sweet potatoes contain more than others.

The bottom line? Spinach is a highly nutritious food. If you have concerns about your iron or calcium levels and don’t eat a lot of other sources of these nutrients, or if you are prone to kidney stones, you may want to moderate your spinach consumption. But eating a well-balanced diet can give you more of the minerals that may otherwise be inhibited by oxalates.

Interference with Medications

Spinach contains large amounts of vitamin K1, in both its raw and cooked forms. Vitamin K1 is known to support natural blood clotting and to prevent excessive bleeding. Getting enough is also important for the strength of your teeth and bones, helping to regulate calcium balance and reduce the risk for fractures.

On the other hand, too much vitamin K1 can reduce the effectiveness of blood thinners like Warfarin. If you’re on Warfarin, or a similar medication, there’s probably no need to completely avoid spinach. Rather, maintaining a consistent intake of spinach and other sources of vitamin K1 can help keep blood levels of this nutrient even. And, of course, this could be a good thing to discuss with your healthcare provider.

May Contain Pesticides

Spinach remains on the Environmental Working Group’s Dirty Dozen list, where it’s listed as the second most pesticide-contaminated produce item when grown conventionally. To help minimize your consumption of pesticides, choose organically grown spinach whenever possible.

How to Choose & Store Spinach

Choose spinach bunches with vibrant green leaves, and avoid spinach that has yellowed leaves as this is indicative of a loss of nutrients. Where possible deal direct with farmers and or support food d0-ops that support farmers. Better still grow it yourself if you have that available, always try to deal get organinc and grown in nutrient rich soil. If you need to store for longer rather than eat fresh go for frozen organic spinach.

If organic is too expensive or not available where you live then stick with conventional grown. When you get home, store fresh spinach in the refrigerator, in produce bags, or in airtight containers. Don’t wash your spinach until you’re ready to eat it, as washing it too early creates a moisture-rich environment that can promote bacterial growth and premature wilting. If you buy fresh spinach that’s not organic, wash it with water and a bit of baking soda when you’re ready to use it. This combination has been shown to be more effective for removing pesticides on the surface of produce than water alone or even commercial produce cleaners.

It turns out that Popeye was right all along, spinach is good for you and can make you strong!, although there some negative effects when added to your lifestyle in a balanced way the health benefits far outweigh any negative factors from oxalates etc. 

John Cawley

John Cawley

John Cawley is the founder of Plant Based Life. John is a Personal Trainer that believes every weakness can be turned into a strength and is passionate about instilling this belief with all clients. John has a lot of experience in helping clients who have had injuries, and is dedicated to helping everyone keep moving and leading a healthy lifestyle, with a big focus on movement, mobility and functional training.