Last week, I gave you the definitive guide to nuts, focusing on the ten most widely available types. Today I give the same treatment to edible seeds. If you’ve ever wondered whether chia seeds are good to eat, or sesame seeds can be legitimate snacks, or flaxseed actually isn’t as good (or bad) as you may have thought, this is the post for you. If you need to choose sides in a long-standing and bitter blood feud pitting the sunflower seed farmers on your mother’s side of the family against the pepita producers on your father’s, this post will help you decide. If your trustafarian friend’s obsession with the industrial applications of hemp is getting on your nerves, this post will give you the tools to analyze his arguments.
As you’ll see below, seeds are nutrient-dense little guys that can really pack in the minerals. Let’s get to it:
Multi-level marketers hawk it. Food manufacturers add a teaspoon of it to juice drinks and double the price. Bulk bins in health food stores across the world stock it. The prominence of the chia seed as a dietary supplement has supplanted its prominence in the “As Seen on TV” market. Should you be eating it?
In an ounce:
- 137.8 calories
- 11.9 g carbs: 9.8 g fiber
- 8.7 g fat 0.7 g MUFA, 1.7 g LA, 5.1 g ALA (omega-3), 1.1 g SFA
- 4.7 g protein
- 11% vitamin B3 (niacin)
- 23% vitamin B6
- 167% vitamin K
- 15% calcium
- 29% copper
- 58% iron
- 26% magnesium
- 34% manganese
- 28% selenium
- 12% zinc
- Chia seed supplementation may modestly reduce CRP levels, at least compared to an equal amount of wheat bran.
- I’m not gonna lie. The broad range of nutrients you get from just an ounce of chia seeds is impressive.
- Chia seed fiber absorbs a lot of water. So much that if you let whole chia seeds sit in liquid, they’ll become gelatinous globules. If you blend the seeds in a liquid, it becomes gelatinous pudding. This is handy for creating dishes with interesting textures, and although no studies show this to be definitively the case, it also indicates prebiotic potential.
- Great for thickening smoothies.
- The magical health claims, which are overblown and exaggerated. In overweight women, chia seed supplementation increased plasma levels of ALA and EPA, suggesting the successful conversion of short chain omega-3s to long chain omesga-3s. However, chia seed had no effect on inflammatory markers or risk factors for metabolic diseases, and DHA decreased slightly in another study of postmenopausal women. Chia also seems to have no effect on bodyweight (good or bad) or disease risk factors in overweight adults. Chia seeds aren’t miracles, in other words. They’re probably just a decent source of micronutrients, (hopefully prebiotic) fiber, and vegetarian-friendly omega-3s.
- The fiber is mostly insoluble, large amounts of which can aggravate IBS and other intestinal conditions.
- Short chain omega-3s (ALA from chia, flax, and hemp) cannot replace long chain omega-3s (EPA and DHA from seafood). Conversion from ALA into EPA/DHA is just too inefficient in humans.
- Phytic acid.
Flaxseed gets a bad rap in the ancestral health community. Sure, when it goes bad it smells like paint thinner. Sure, flaxseed oil is actually used as paint thinner. It doesn’t taste particularly good, and the seeds get stuck in your teeth if you’re not careful about thoroughly milling them. The accolades it receives in both conventional and alternative health circles can be cloying, I know. And yeah, the omega-3s aren’t a good replacement for fish fats. But don’t count flaxseed out just yet. As you’ll see, it has some interesting components that may offer unique health benefits — even if you eat plenty of wild salmon.
In an ounce:
- 151.4 calories
- 8.2 g carbs: 7.7 g fiber
- 12 g fat: 2.1 g MUFA, 6.5 g ALA, 1.7 g LA, 1 g SFA
- 5.2 g protein
- 39% vitamin B1 (thiamine)
- 38% copper
- 20% iron
- 26% magnesium
- 31% manganese
- 13% selenium
- 11% zinc
- Can reduce hypertension. A total of 30 grams of milled flaxseed every day “induced one of the most potent anti-hypertensive effects achieved by a dietary intervention,” but only in those patients with actual hypertension; it didn’t reduce blood pressure if subjects were normotensive.
- Flaxseed lignans reduce oxidized LDL, an independent risk factor for heart disease.
- A milled mixture of 18 g flax, 6 gsesame, and 6 g pumpkin seeds administered to hemodialysis patients lowered inflammatory markers, improved omega-3 status (due to the flax, no doubt), and lowered insulin resistance.
- Whole flax is notoriously indigestible. If you want to make the flax components more bioavailable, mill or blend it before consuming.
- Phytic acid is high. It’s a seed, so there’s really no getting away from phytic acid.
If you’ve spent any time in hazy college dorm rooms with towels blocking the space under the door and “Buffalo Soldier” playing on repeat, you’ll have heard about the universal utility of hemp. It makes better, stronger, and more breathable clothing than cotton. It can replace synthetic building materials. It doesn’t use many pesticides. It’ll save the world, man. And, they say, it can even feed it. Yeah? Well, I wouldn’t go quite that far, but hemp seed is a viable food source, certainly edible and pleasantly nutty. How does it stack up nutritionally?
In an ounce:
- 149.1 calories
- 7.8 carbs: 7.8 g fiber (all fiber)
- 10.1 g fat: 1.1 g MUFA, 2.2 g ALA, 4.8 g LA, 0.8 g SFA
- 7 g protein
- 24% vitamin A
- 63% copper
- 50% iron
- 33% magnesium
- 86% manganese
- 13% selenium
- 18% zinc
- Hemp seed is one of the few sources of stearidonic acid, an intermediate omega-3 fat in the conversion pathway from ALA to EPA with a knack for increasing the EPA content of red blood cells in humans.
- Hemp seeds contain a host of bioactive compounds with potentially beneficial health effects (PDF), including cannabidiol, beta-sitosterol, methyl-salicylate, tocopherols, and unique antioxidants.
- Hemp seed is high in phytic acid, like essentially all seeds. A recent study into Italian and French cultivars found a range of 64.9-74.1 g phytate/kg hemp seed (PDF), or 6.49-7.41 g/100 g.
- Allergy (though uncommon).
Pumpkin seeds, or pepitas, are my favorite. Roasted with a light dusting of sea salt and eaten as snacks, scattered across a salad for texture and crunch, lightly toasted and ground up to make a green mole sauce? It’s a versatile little seed. I have fond childhood memories of scooping out the innards of Halloween jack-o-lanterns, separating the seeds, and roasting them in the oven. That pumpkin and squash seeds get lumped into the same category whichever online nutritional database you use, though, has always irked me. But that’s what I have to go on. Don’t blame me if you rely exclusively on delicata squash seeds for your magnesium and they end up having very little.
In an ounce:
- 162.7 calories
- 4.2 g carbs: 1.8 g fiber
- 13.9 g fat: 4.5 g MUFA, 5.6 g linoleic acid (LA), 2.4 g SFA
- 8.5 g protein
- 40% copper
- 29% iron
- 37% magnesium
- 55% manganese
- 20% zinc
Most research has looked at the health effects of pumpkin seed oil rather than the pumpkin seeds themselves. Still, since the seeds contain the oil, any benefits the oil confers should also apply to seed eaters.
Pumpkin seed oil has been shown to:
- Improve nocturnal urination in patients with overactive bladders (and by “improve” I mean reduce).
- Increase hair growth in men with androgenetic alopecia.
- Reduce aflatoxin toxicity in mice.
- Have antihypertensive effects.
As for the seeds?
- “Pumpkin byproducts,” aka seeds, contain significant levels of antioxidant and bioactive compounds. Same for the seed fiber. The pumpkin seed lipids also contain bioactive compounds relevant to human health.
- In men with Benign Prostatic Hyperplasia, a year of supplementing with pumpkin seeds every day reduced their International Prostate Symptom Score compared to placebo.
- They can increase iron status in adult women.
- Pumpkin seeds are quite high in phytic acid, with one recent study placing the content at 4.2 g phytate/100 g pumpkin seed. If that holds for other pumpkin seeds, you’d be looking at close to a gram of phytate in an ounce. Somewhat reassuring is the fact that adult women who added pumpkin seeds to their diet saw an increase in iron status
- Rectal bezoars.
- Pumpkin seed aspiration.
We don’t normally think of sesame seeds as a snack item because trying to snack on a baggie of sesame seeds doesn’t really work. They’re too small to chew and they don’t handle like larger seeds. Instead, sesame seeds are garnishes. They’re sprinkled over dishes as finishers and flavorers. If you want to use larger amounts of sesame, you grind it up into tahini paste, like in hummus, or mix the whole seeds with molten sugar to form clusters or brittle. As a result, sesame seeds rarely contribute much caloric bulk to a person’s diet. Is that a mistake?
In an ounce:
- 178.9 calories
- 3.3 g carbs: 3.3 g fiber (all fiber)
- 17.4 g fat: 6.8 MUFA, 0.1 ALA, 7.2 LA, 2.6 g SFA
- 5.8 g protein
- 17% vitamin B1 (thiamine)
- 10% vitamin B3 (niacin)
- 44% copper
- 23% iron
- 23% magnesium
- 18% manganese
- 18% selenium
- 17% zinc
- 40 grams a day of sesame seed improved clinical signs and symptoms in patients with knee osteoarthritis.
- Sesame paste (just ground seeds) improved triglycerides and triglyceride/HDL ratios.
- In hyperlipidemic patients, sesame seed consumption improved lipid numbers and (most importantly) lowered lipid oxidation.
- Sesame meal lowered oxidative stress, improved hypertensive status, and increased antioxidant capacity in pre-hypertensive patients.
- A potential benefit to sesame seed consumption are its bioactive lignans, which show anticancer, antihypertensive, cardioprotective, and antioxidant effects.
- It’s really hard to eat enough sesame seeds to get into trouble. I guess you could just spoon the things into your gaping maw and chew for a few minutes and hope for the best, but why?
- Phytic acid.
Growing up a young lad in Maine, my summertime roaming radius was a dozen miles across. And if you wanted to find me, you followed the sunflower seed hulls I spat out at a steady clip all day long. Eating sunflower seeds and spitting out the hulls is about as American as apple pie. Actually, seeing as many Native American tribes grew and harvested sunflowers right along with their squash, corn, and beans, sunflower seeds are way more American than apple pie. And even though they exist, let’s ignore those deviant monsters who eat the entire shell along with the seed inside.
In an ounce:
- 165.6 calories
- 5.7 g carbs: 2.4 g fiber
- 14.6 g fat: 5.3 g MUFA, 6.5 g LA, 1.3 g SFA
- 5.9 g protein
- 35% vitamin B1 (thiamine)
- 15% vitamin B3 (niacin)
- 22% vitamin B6
- 16% folate
- 66% vitamin E
- 57% copper
- 19% iron
- 22% magnesium
- 24% manganese
- 27% selenium
- 13% zinc
- Sunflower seeds possess considerable levels of antioxidant compounds which may reduce oxidative stress.
- Rich in phytosterols, which lower cholesterol.
- Rich in phytosterols, which lower cholesterol. Huh? Isn’t that a benefit? Maybe, but there’s also considerable evidence that elevated plasma levels of phytosterols — which are kinda like the plant version of cholesterol — are associated with atherosclerosis and heart disease. Meanwhile, save for studies in animals (who are largely herbivorous and habitual consumers of a high-phytosterol diet), phytosterol supplementation has never been shown to reduce the incidence of heart disease or inhibit atherosclerosis in people. My inclination is to avoid “phytosterol-enriched” products and inordinate amounts of phytosterol-rich foods like sunflower seeds. Normal amounts of seeds should be fine.
- Springtime fecal impaction.
- High in phytate.
Seeds are potent, made all the more so by the diminutiveness that masks them. It’s easy to absentmindedly snack all day long and end up eating an entire cup of pumpkin or sunflower seeds. They’re almost uniformly high in phytic acid, which may have its good side but definitely can impair mineral absorption at high levels. Many are high in omega-6 fats, which aren’t really a problem in the context of whole foods but may be if those foods are eaten to excess. And the rich body of evidence supporting regular nut consumption just isn’t there for seeds. I suspect seeds are quite beneficial in the right amounts given their nutrient levels and the limited research that does exist in their favor, particularly if you soak and perhaps even sprout them, but exercise caution just the same. We are neither birds nor rodents, and a seed-based diet probably doesn’t suit us.
That’s it for today, folks. How’s your relationship to edible seeds? Do they agree with you? What are your favorites?
Thanks for reading, everyone. Take care.
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