Super food or expensive pond scum? Is this “green food” worth the greenbacks? Find out what nutritional benefits spirulina offers. Also, we review promising research on saffron for mental health and cognition.
Super food or expensive pond scum? Is this “green food” worth the greenbacks? Find out what nutritional benefits spirulina offers. Also, we review promising research on saffron for mental health and cognition.
Related listening:
Why You Need More (Not Less) Phytic Acid in Your Diet (Nutrition Diva #612)
Are powdered green supplements like AG1 worth the money? (Nutrition Diva #754)
Research references:
Blue-Green Algae (Medline Plus)
Hello and welcome to the Nutrition Diva podcast, a show where we take a closer look at the latest nutrition trends, products, and claims so that you can make more informed decisions about what to eat. I’m your host, Monica Reinagel, and today I have a couple of questions from listeners about specific foods and supplements.
Larry wrote to ask what I thought about spirulina. He says it’s one of many ingredients in a green powder drink mix that he recently purchased. But before we dig into that, a question from Donny, who wrote:
“I've heard there are benefits to taking saffron as a supplement. including treatment of Alzheimer's disease as well as it being an anti depressant and an anticonvulsant, among other things. Is there any truth to these claims?”
There is, in fact, some intriguing research on saffron and its effects on the brain. It appears to regulate neurotransmitters, it may help protect the brain against the effects of stress and even promote neuroplasticity. Although this is all very exciting, the clinical research is still very much in the preliminary stages, limited to small, short-duration studies that need to be replicated in larger and more diverse populations before we can feel confident in their validity.
That said, multiple small trials have shown a moderate improvement in symptoms of depression and anxiety, in some cases rivaling the impact of prescription anti-depressants. Other small trials found that saffron led to modest cognitive improvement in people suffering from Alzheimer’s disease.
Saffron supplements should be completely avoided by anyone who is pregnant or could become pregnant. And this is not the usual situation where there is insufficient evidence to demonstrate that it is safe during pregnancy. In this case, there is actual evidence to suggest that it is not safe. (The amount of saffron that you’d be exposed to from normal dietary intake would not be a concern.)
Other than during pregnancy, the supplement is generally safe when used at the typical dosage of 30mg a day–although a variety of side effects have been reported, including nausea, dry mouth, headache, and drowsiness. Higher dosages have produced more serious issues and are not recommended.
All in all, Donny, this is a story that’s not quite baked but definitely worth following as more research is conducted.
And now, let’s turn our attention to Larry’s question about spirulina.
For those who aren’t familiar with it, spirulina is a dark green algae that grows on the surface of lakes. In other words: it’s basically pond scum—but really nutritious pond scum! The ancient Aztecs used to skim spirulina algae off the surface of lakes and dry it into cakes, which served as an important source of nutrients. Today, you’re most likely to find dried spirulina powder in the health food store, where it’s sold as a “green” supplement, or added to smoothies, juices, and other “health” drinks..
Spirulina is a good source of plant-based protein. Adding an ounce of spirulina powder (which is about 3 tablespoons) to a smoothie, for example, would add a pretty significant amount of protein—around 15 grams, which is what you’d get in two jumbo eggs or a half a serving of chicken breast. However, like most plant-based proteins, spirulina is not a complete protein. Similar to legumes, spirulina is a good source of lysine but contains only limited amounts of methionine (an amino acid which is supplied by grains).
Spirulina also provides various vitamins, minerals, and essential fatty acids. It’s particularly rich in beta-carotene and vitamin K, although if you’re eating a reasonable amount of fruits and vegetables, you’re probably getting plenty of these vitamins already.
Although it does contain several B-vitamins, spirulina is not a reliable source of vitamin B-12. Although the label may show a high level of B-12, the form of B-12 in spirulina is largely inactive in humans. Although certain processing methods have been found to increase the bioavailability, vegans should not rely on spirulina as a source of B-12
Spirulina is also quite high in iron—however, your body may not absorb very much of it. Spirulina also contains phytates, which bind to iron in the gut and reduce the amount you are able to absorb. So, if you are vegetarian or vegan, you wouldn’t wouldn’t want to rely on spirulina as your primary source of iron. In fact, spirulina can even reduce the absorption of iron from other foods eaten with it.
This is not to throw shade on phytates. These natural plant compounds also play a beneficial role in human health and nutrition. You can learn more about that in episode #612.
Like many nutritious plant foods, spirulina has antioxidant effects that reduce oxidative stress. Research also shows that it may boost immune function. In fact, the National Institutes of Health recommends that people with auto-immune diseases such as multiple sclerosis, lupus, or rheumatoid arthritis should avoid it for that reason. The concern is that boosting the immune system could increase the symptoms of auto-immune diseases. Frankly, this seems like an abundance of caution to me as the effects on immune function that have been observed are relatively modest.
Spirulina has also been found to have positive effects on a range of cardiovascular and metabolic parameters, including blood pressure, cholesterol, blood sugar, and blood clotting. In most cases, the impacts were relatively modest, but enough that the NIH recommends caution when combining spirulina with other herbs or medications that may lower blood pressure, blood sugar, or thin the blood, to avoid compound effects. And because of the blood thinning actions, spirulina is one of several herbal or nutritional supplements that should be discontinued prior to surgery. (Others in that group include ginger, garlic, fish oil and vitamin E. )
And finally, there’s evidence that spirulina promotes the growth of beneficial bacteria in the gut– a benefit that plenty of other prebiotic foods can claim as well.
And if this is just one of many “superfoods” in your powdered green drink, the amount of spirulina that you’re actually getting per serving may be pretty minimal.
Related Listening: 754 https://nutrition-diva.simplecast.com/episodes/are-powdered-green-supplements-like-ag1-worth-the-money
Folks promoting spirulina often make a lot of claims for special super-powers, such as suppressing the appetite, aiding with weight loss, “energizing” or “alkalizing” the body—but I’d consider most of it to be marketing hype.
What are the Disadvantages of Spirulina?
Although spirulina does contain a lot of important nutrients, it’s not cheap. An ounce of spirulina will run you between $1.50 and $3.00. You could get the same nutrients from other sources more cheaply.
Spirulina isn’t exactly prized for its flavor, which could best be described as…well, algal. Most people enjoy spirulina mixed with other ingredients. Being a pleasure glutton myself, I prefer to get my nutrients from foods I enjoy eating.
There have also been concerns about contamination in spirulina and other blue-green algae supplements. Spirulina can absorb and accumulate heavy metals from its growing environment, including arsenic, cadmium, lead, and mercury. The presence of these metals in supplements can pose significant health risks, particularly if these supplements are consumed regularly over a long period. Products with labels indicating testing for heavy metals can provide an added layer of safety.
The Bottom Line on Spirulina
Spirulina is undoubtedly nutritious. It may offer a valuable source of protein, especially for vegans. If you’re viewing it as a sort of vitamin supplement, it’s on the expensive side—and doesn’t provide anything you can’t get from a healthy diet. If it’s the more targeted health benefits you’re after, such as the impact on blood pressure or blood sugar, there are likely to be other dietary interventions or nutritional supplements that give you a bigger bang for the buck.
If you have a question you'd like me to answer, you can email me at nutrition@quickanddirtytips.com You can also leave me a message at 443-961-6206
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Nutrition Diva is a Quick and Dirty Tips podcast and is supported by a fantastic team, which includes Brannan Goetschius, Nathan Semes, Davina Tomlin, Holly Hutchings, Morgan Christianson, and Kamryn Lacy.
That's all for this episode. Thanks for listening! I'll see you next week.