Seeds are packed full of nutritional goodness, essential to a plant-based diet. From seeds you can get healthy fats like omega 3 and 6, B vitamins, protein and trace minerals. They can be eaten raw, roasted, sprouted or ground into seed butter.
As they must contain all the energy a plant needs to start out in life, seeds are pretty high in calories – particularly fat. That said, it’s largely ‘good’ fat. Due to their high fat and fibre content, seeds can also slow down the absorption of food, so you feel fuller for longer.
Lignans – a type of phytoestrogen, especially found in flax seeds, but also notable in chia and sesame – are even thought to have fat-burning qualities. In addition, they’re potentially beneficial for cardiovascular disease, breast cancer (and other hormone-related cancers), diabetes and menopausal symptoms (1).
Let’s look at some nutritional benefits of seeds, followed by a couple of pitfalls, then we’ll have a closer look at 6 of the most common types.
Below are the nutritional values of 6 common types…
Bear in mind that 100g is quite a lot of seeds 🙂
Pitfall #1: Antinutrients
Seeds can be high in antinutrients such as phytates. The role of phytates is to stop the seed germinating too early, then to protect the mature plant from predators. Of all the parts of a plant, the seed (especially its husk), will most likely have the highest concentration of phytates.
Roasting or sprouting will help reduce the level of phytic acid in seeds. Recent research has shown that there is no benefit to soaking nuts. Whole nuts showed no discernible change in antinutrient levels. Chopped nuts showed a reduction, but also a reduction in minerals, cancelling out the benefit of soaking (2). We assume the same would apply to seeds, as they have a similar nutritional profile.
You can buy some seeds dehulled – without the husk – so they’ll already have lower levels of phytic acid. Flax and chia are sold whole. Pumpkin and sunflower are generally sold as kernels or ‘hearts’ – without their tough outer shell. Sesame and hemp are sold either whole or dehulled.
If you’re going to sprout seeds, make sure they’re raw. Industrially removing the shell often involves heat processes, meaning the seed can’t be activated. Avoid hemp hearts or de-hulled sesame in this case. Pumpkin and sunflower hearts are usually still raw, but check the packaging. Hemp, chia and flax are tricky (though not impossible) to sprout, because they develop a gel-like coating when wet. More tips on that at a later date. If you sprout any seeds, rinse them carefully, refrigerate and use them within a couple of days. Hygiene is very important here, as they can easily go mouldy.
The simplest way to reduce phytic acid in seeds is to roast them in the oven, or toast them dry in a pan. As long as you don’t let them go too far, they’ll retain most of their nutritional value, and their flavour will be deliciously enhanced. We roast at 180°C (355°F), with the seeds spread out in a thin layer. The timing depends on the size and quantity, but it’s usually around 10-15 minutes. Keep a very close eye on them, and stir them up every 5 minutes. Alternatively, you can just use them in baking or cooking.
If you soak seeds, make sure you dehydrate and/or roast right away. We soak pumpkin, sunflower and sesame for 4 hours in salt water, rinse, then dehydrate before roasting. We don’t pre-soak hemp, chia or flax if we’re cooking them, because of the gel-like coating.
Pitfall #2: Essential Fatty Acids
Omega 3 and 6 are both essential in the diet, but they need to work in harmony. In short, omega 3 and one type of omega 6 – gamma linolenic acid – have an anti-inflammatory effect on the body. The most common form of omega 6 though – linoleic acid – has an inflammatory effect. So if you have too much 6 and not enough 3, you could be at higher risk of inflammatory conditions such as arthritis, Crohn’s disease, heart disease and cancer (3). Humans are thought to have evolved with a 1:1 ratio of 6 to 3, but in the typical Western diet it’s more like 16:1 (4). This is largely due to the increased consumption of processed oils, such as soy and corn oil.
On a plant-based diet it can be especially tricky to get the omega balance right, while also getting a good protein-carbohydrate balance, as most nuts and seeds tend to be higher in 6 than 3. Notable exceptions are chia and flax, so it’s worth trying to add them in where possible. But those higher in 6 and lower in 3 – sesame, sunflower and pumpkin – are also high in monounsaturated fats, which can help reduce inflammation to some extent.
A further complication is that the omega 3 found in chia and flax is alpha-linolenic acid (LNA), which is harder for the body to process than the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) most commonly found in animal products (3). So you may also want to consider taking an omega 3 supplement. Vegan types made from marine algae – high in DHA and EPA – are widely available. We use Testa. At the time of writing there are no certified organic options. We asked Testa about that, and this was their response:
“Algae oil is not produced in an agricultural environment and the principles of organic agriculture therefore do not apply here. However, the algae oil is produced under very controlled conditions, making our oil very pure and fresh compared to fish- or krill oil.”
High in calcium, magnesium, iron, phosphorus, potassium, zinc. High in omega 6, low in omega 3.
Sesame is one of the oldest known seed crops, cultivated as far back as 3000 years ago. Big producers are Tanzania, India, and Sudan.
The sort we usually see in shops is white when de-hulled (as pictured below). The black and brown varieties are most commonly seen in Asian cuisine, where the oil is also used as a flavouring. Sesame is very popular in the Middle East and Africa, often ground into tahini.
Of all these 6 common seeds, sesame are highest in phytosterols, which help reduce cholesterol levels in the blood (5). They are also high in lignans.
Although rare, sesame can cause a serious allergic reaction in some people. Apart from that, these little seeds are pretty amazing.
High in B1, B3, B5, B6, B9, E, magnesium, phosphorus, potassium, zinc, manganese, copper, omega 6. Low in omega 3.
Sunflower seeds are typically eaten raw or roasted as a snack. They’re also a popular addition to bread. Increasingly they’re ground into sunflower butter (AKA sunbutter), as an alternative to peanut butter. This is useful either for those allergic to peanuts, or those following a strict paleo diet (peanuts are technically legumes).
Of all these 6 seeds, sunflower has by far the highest level of vitamin E.
High in vitamin B1, B3, B9, iron, copper, magnesium, phosphorus, potassium, manganese, zinc, omega 3 and omega 6.
Let’s start with the elephant in the room. As it’s related to cannabis, hemp is surrounded by suspicion. In fact it’s only a very distant cousin, containing negligible amounts of the psychoactive THC (6). Even that may be reduced by naturally occurring CBD (cannabidiol). Some countries, including the UK, have very strict regulations for hemp production and import. To be sold for consumption in the UK it must have practically no THC, so the sort you buy from health food stores can be considered safe (7).
That’s good news, as hemp seed is an incredible superfood. It has the highest protein level of all these common seeds, including all 9 essential amino acids, and a further 11 besides. It’s also the highest in magnesium, potassium, zinc and manganese.
Hemp has a decent amount of omega 3. It’s also high in omega 6, but some of this is GLA, so the overall balance of omega oil is considered beneficial.
Hemp seed is well known for suppressing the appetite. This is especially due to the high fibre content in the whole seeds (around 30% of weight), as opposed to just the hearts. As it has good levels of both soluble and insoluble fibre, it also helps digestion, and is believed to support healthy gut flora.
Many people claim hemp is free from phytic acid. We find that hard to believe, and have not found any scientific evidence, so we’ll assume it’s a myth.
High in protein, iron, copper, magnesium, phosphorus, potassium, manganese, zinc and omega 6. Low in omega 3.
The pumpkin seed, or pepita, has been prized in the Americas since Aztec times. It contains almost 30% protein. Pumpkin seeds are high in antioxidants. They are also thought to have antiviral, antifungal and antiparasitic qualities (8).
High in vitamin B1, iron, copper, magnesium, phosphorus, potassium, zinc. Very high in omega 3 (as alpha-linolenic acid) and with a good 3 to 6 ratio.
Flax, AKA linseed, is known to have been cultivated in Europe for at last 5000 years – initially for linen production and linseed oil. Today Canada is the biggest producer.
Flax seeds are an especially rich source of lignans (9), and are also high in antioxidants. Flax is high in both soluble and insoluble fibre. When wet it forms a gel-like coating, aiding digestion, improving nutrient absorption and helping you feel fuller for longer.
Flax can pass through the gut intact, so make sure you either sprout or grind it before use, unless you’re ready to chew it very thoroughly 🙂 It can be bought pre-ground, but will lose its nutrients within a few days in this form. Best to buy it whole and grind it in a food processor or coffee mill at home, then refrigerate and use it as soon as possible.
Flax seeds soak up a lot of water, so make sure you drink plenty if you eat a significant amount. Due to the gel substance they form, they’re often used as an egg replacement in baking. Just mix 1 tbsp of ground flax with 3 tbsp of water and leave it to soak for a few minutes. Although this won’t rise as eggs do, it works well as a binder.
High in vitamin B3, calcium, iron, magnesium, phosphorus and manganese. Really good for omega 3 and with a high 3 to 6 ratio. Very high in copper.
The chia seed is native to Mexico, and was an important crop to the Aztecs – so valuable it was even used as currency. It was taken for endurance by warriors as far back as 3500 BC. In modern times it’s prized by athletes for improving stamina and aiding hydration, as it can absorb up to 12 times its weight in water.
As with hemp and flax, chia forms a gel when ingested. Along with its high fibre content, this helps slow down digestion, suppresses the appetite. In the case of chia, it has even been shown to regulate blood sugar, potentially helpful for diabetes, and to aid the prevention of cardiovascular disease (10).
More than 50% of the fat in chia seeds is omega 3. Around 20% of their weight is protein. Like flax, chia is sometimes used as an egg replacement in recipes.
Whichever seeds you choose, make sure to buy them as fresh as possible, and store them in an air-tight container. Although they will be edible for several months, their nutritional value will naturally degrade over time.
We get all our organic seeds from Healthy Supplies. For their own label products they tell you the batch date and source online, and they have good bulk prices. (We don’t get a commission from them 🙂 )
Got any tips or questions of your own about seeds? Leave us a comment below, we’d love to hear from you.