A few weeks ago, I wrote that I intended to verify claims that purslane (Portulaca oleracea) has “amazing health benefits.” I had read an article about this supposedly nutritional plant that seemed a little too good to be true. Being ever the skeptic, I dug in—and learned some things. I’ll use this as a case study on how to verify health claims that you read online.Here is what the article said about purslane as a food crop:
- It is GMO free, contains essential antioxidants and vitamins.
- Its high protein levels will give you strength.
- It is rich in Omega 3 fatty acids. So it can protect you from stroke and heart diseases. Moreover, it lowers the chance of ADHD in children, autism and other developmental disorders.
- It contains the most vitamin A of all green leafy vegetables that can protect you from cancer.
- It contains calcium and iron that are very important for the bones.
- It provides six times more vitamin E than spinach and seven times more beta carotene than carrots.
- It is rich in dietary fiber and low in calories.
- It’s also rich in vitamin C, magnesium, riboflavin, potassium and phosphorus.
Of course, if all this is true, we should all be cultivating purslane instead of weeding it out! (Don’t toss it on the compost heap, however, as parts of the plant can re-root, and you’ll just have more!)
Let’s take these claims one at a time. My numbers are based on a 100 gram serving of raw purslane, which is quite large—over two cups’ worth.
- “It is GMO free….” Yup, it’s GMO free. No one has bothered to mess with purslane DNA. In fact, all leafy greens are GMO free.
- It has high protein levels. Um, not so much. 100 grams provide 2.03 grams of protein, or 4% of the recommended daily value (DV). The same amount of spinach has 2.86 grams, 6% DV. Of course, most of us don’t eat leafy green vegetables for their protein.
- “It’s rich in Omega 3 fatty acids.” A study in the Journal of the American College of Nutrition concluded that “purslane is a nutritious food rich in omega-3 fatty acids and antioxidants.” “Moreover, it lowers the chance of ADHD in children, autism and other developmental disorders.” Conclusive studies are lacking, but it’s a current area of research.[i] Stating that it lowers the chance of these disorders is premature.
- “It has the most vitamin A of all leafy green vegetables.”
- I found this claim scattered across the internet, but it’s not true. Purslane does have 1,320 IU (international units), or 26% DV. Spinach, on the other hand, has 9,377 IU, or 188%, making it a far better source. “… that can protect you from cancer.” There is currently no consensus that vitamin A protects against cancer. Again, studies are underway.
- “It contains calcium and iron.” Yes… it contains 65 mg (6% DV) of calcium, not at all a rich source. There’s more iron… 1.99 mg, or 11% DV—still not an overwhelmingly rich source, but not bad. For comparison, spinach has 99 mg (10% DV) calcium, and 2.71 mg, or 15% DV iron.
- “It provides six times more vitamin E than spinach…” First of all, vitamin E deficiency is very rare, and is usually due to an underlying medical issue, not a dietary one. But yes, it’s true. Purslane provides 81% of the DV of vitamin E while spinach offers only 7%.
- “…and seven times more beta carotene than carrots.” I wasn’t able to find a beta carotene value for purslane. However, since beta carotene is one of the precursors to vitamin A, we can look at the vitamin A levels as a reasonable comparison. As mentioned above, purslane has 1,320 IU while carrots pack a whopping 16,706 IU, or 334% DV! There’s no contest.
- “It is rich in dietary fiber and low in calories.” There are only 20 calories in that 100 gram serving, so it is definitely low in calories. However, while many articles claimed that purslane is high in fiber, I only found one site that provided an actual number. According to those nutrition facts—there isn’t any! (Note that many data sets confuse “we don’t know” with zero.)
- “It’s also rich in vitamin C, magnesium, riboflavin, potassium and phosphorus.” Here are the stats: Vitamin C: 21 mg, or 25% DV; magnesium: 68 mg, or 19% DV; riboflavin: .112 mg, or 9% DV; potassium: 494 mg, or 11%; and phosphorus: 44 mg, or 6%. Are those rich sources? It all depends on how you define “rich.”
What can we conclude from all these numbers? Things you read online can be accurate—or not. If it’s a topic important to you, then spend a little time and check the facts. Looks for reputable sources, as many popular sites simply repeat things they find elsewhere, regardless of how true it is. The don’t care—they simply want to sell their products, or amass eyeballs for their advertisers.
And when it comes to purslane—if you like it, eat it. If not, there are other sources for its nutrients. Just don’t let it go to seed in your garden unless you love pulling weeds!
[i] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5634395/ and https://clinicaltrials.gov/ct2/show/NCT01248728. Note that the National Institute of Health does not assess the quality of the studies it lists. These were behind a paywall, so I couldn’t read them for myself.