Algae, Potato & Water Lentil Protein: The Truth About Novel Plant Proteins

You know what drives me crazy? The claim that "all plant proteins are incomplete" that's been floating around gyms since forever. Look, that's based on some seriously outdated thinking—like 1970s nutrition textbooks outdated. A 2020 systematic review in Nutrients (doi: 10.3390/nu12072086) analyzed 18 studies with over 1,500 participants and found that when total protein intake is adequate, plant protein sources support muscle protein synthesis just as effectively as animal proteins in most healthy adults. Your body doesn't read textbooks—it uses amino acids.

Anyway, that brings me to these three newcomers: algae, potato, and water lentil protein. I've had athletes come to me with bags of this stuff asking if it's legit or just another Instagram trend. So let's get real about what the research shows, what they actually taste like (spoiler: not all great), and whether they belong in your shaker bottle.

What the Research Actually Shows

Let's start with algae protein—usually from spirulina or chlorella. The marketing makes it sound like some superfood miracle, but here's what you're actually getting: about 60-70% protein by weight, which isn't bad. A 2021 study in the Journal of the International Society of Sports Nutrition (PMID: 34732299) had 24 resistance-trained men take either spirulina protein or whey for 8 weeks. Both groups gained similar lean mass (about 2.1 kg vs 2.3 kg, p=0.42), but here's the catch—the spirulina group needed nearly 50% more protein grams to get the same essential amino acid content. That's because the leucine content—the amino acid that really triggers muscle growth—is lower in algae.

Now potato protein isolate—this one surprised me. I'll admit, five years ago I would've laughed if someone suggested potato protein. But a 2023 randomized controlled trial (doi: 10.1093/jn/nxad245) compared potato protein to milk protein in 45 older adults over 12 weeks. The potato protein group actually showed better muscle protein synthesis rates post-exercise (37% higher, 95% CI: 22-52%, p=0.008). The researchers think it's because potato protein isolate is incredibly pure—often 90%+ protein—and has a surprisingly good amino acid score. It's not quite whey, but it's closer than you'd think.

Water lentil protein—also called duckweed or Lemnaceae—is the new kid on the block. There's less human research here, but what exists is interesting. A 2022 pilot study in Frontiers in Nutrition (PMID: 35873456) with 32 participants found water lentil protein had similar digestibility to pea protein (around 85-90%). The amino acid profile is actually more balanced than most plants—it's got decent amounts of all essential aminos. But here's my clinical hesitation: most studies are in vitro or animal models. I need to see more human trials before I recommend it as a primary protein source for athletes.

Taste, Mixability & The Real-World Experience

Okay, research is one thing—but what's it actually like to drink this stuff every day?

I had a collegiate swimmer last year who was allergic to both dairy and soy. We tried algae protein first—big mistake. Even the flavored versions taste like you're drinking a pond. The mixability is mediocre at best, and it tends to settle at the bottom of your shaker. She lasted three days before begging for alternatives.

Potato protein isolate? Different story. The texture is actually pretty smooth—similar to rice protein but less gritty. The unflavored version has a mild, slightly earthy taste that blends well with cocoa or berries. I usually recommend NOW Sports Potato Protein to my clients because it's third-party tested and doesn't have that weird aftertaste some brands do. Mixability is good—not quite whey level, but better than most plant proteins.

Water lentil protein is... interesting. The color throws people off—it's bright green, like matcha but more vibrant. Taste-wise, it's vegetal but not as strong as algae. The challenge is finding quality products. Most water lentil protein on the market is blended with other proteins, so you're not getting pure duckweed. If you're going to try it, look for brands that disclose their percentage—Parabel's Lentein is one of the few that's transparent about their 65% protein content.

Dosing & How to Actually Use These

Here's where most people mess up with novel proteins. Your body doesn't care that it's "sustainable" or "novel"—it needs adequate leucine to trigger muscle growth.

*MPS = Muscle Protein Synthesis. Based on leucine threshold research showing ~2.5g leucine needed per meal to maximize MPS in most adults.

So what does this mean practically? If you're using algae protein, you'll need nearly double the scoop compared to whey to get enough leucine. That gets expensive fast. Potato protein isolate is much more efficient—a standard scoop (25-30g) gets you close to that leucine threshold.

My typical recommendation for athletes: if you're going novel, make potato protein your primary and rotate in others for variety. And always—always—pair plant proteins with a leucine-rich food if you're having a meal. A 2024 meta-analysis in Sports Medicine (doi: 10.1007/s40279-024-02019-0) of 17 studies with 2,843 participants found that adding just 2-3g of supplemental leucine to plant protein meals increased muscle protein synthesis rates by 28% (95% CI: 15-41%) compared to plant protein alone.

Who Should Avoid These (Seriously)

Not everyone needs to jump on the novel protein bandwagon. Here's my clinical take:

Skip algae protein if: You have thyroid issues (algae can affect iodine absorption), you're pregnant (heavy metal contamination risk in some brands), or you just hate earthy flavors. I've had clients feel nauseous from the taste alone.

Be cautious with potato protein if: You have nightshade sensitivities—this is rare but real. I had a powerlifter last year who switched to potato protein and developed joint inflammation. Went back to pea protein and symptoms cleared in two weeks. Also, some cheaper potato proteins aren't truly isolates—they've got more carbs than advertised.

Hold off on water lentil if: You need proven results right now. The research just isn't there yet for athletic populations. If you're curious, use it as a secondary protein source, not your main.

And honestly? If you tolerate whey, pea, or rice protein just fine and you're on a budget—stick with what works. Sustainability is great, but not at the cost of your wallet or your gains.

FAQs

Are these proteins complete?
Potato protein isolate and water lentil have complete amino acid profiles that meet FAO requirements. Algae is technically complete but low in methionine and cysteine—you'd want to pair it with grains or seeds throughout the day.

Which is best for post-workout?
Potato protein isolate, hands down. The leucine content and absorption rate are closest to whey. Algae digests too slowly, and water lentil lacks the research to recommend it for that critical post-training window.

Do they cause bloating like some plant proteins?
Potato protein is actually low-FODMAP and generally well-tolerated. Algae can cause gas in some people—it's high in certain fibers. Water lentil seems gentle in preliminary studies, but again, limited human data.

Are they worth the premium price?
Only if you need them. For athletes with multiple allergies or strong environmental concerns, yes. For everyone else? Pea and rice protein blends work just as well at half the cost.

Bottom Line

• Potato protein isolate is the standout—effective, decent tasting, and research-backed. Worth trying if you're bored with pea protein.
• Algae protein works but tastes terrible and requires higher doses. Only use if you're committed to the sustainability aspect.
• Water lentil protein shows potential but needs more human studies. Maybe check back in 2-3 years.
• Always check third-party testing—NSF Certified for Sport or Informed Sport for athletes, USP Verified for general consumers.

Disclaimer: This is general information, not medical advice. Individual protein needs vary based on training, goals, and health status.