Seeds are widely recommended as part of a healthy, balanced diet – and with good reason. They’re packed with healthy plant fats, fibre, protein, vitamins, minerals and antioxidants. Plus, they’re naturally gluten-free. As an excellent source of healthy polyunsaturated fats, seeds are superfoods that play a role in weight management, as well as the prevention of life-threatening chronic diseases such as heart disease, diabetes and cancer.
Judith Johnson and Gabriel Eksteen, two registered dieticians from Cape Town, South Africa, give us some insight into the “seediest characters” out there and how to include them in your diet.
These tiny black seeds originate in Central America, dating back to the Mayan and Aztec cultures. Ever since, native South Americans have enjoyed them, often using them to up endurance during fitness training.
Chia seeds are a good source of protein, iron, folate, calcium, magnesium, zinc and manganese, and are very high in antioxidants, which are known to protect us against disease-causing free radicals.
Their claim to fame, however, is their high omega-3 content. Chia seeds are one of the best plant-based sources of omega-3 fatty acids, which are required for optimal health throughout one’s life. If you consume a typical western diet, chances are that you’re not getting enough of these essential fatty acids.
Chia seeds are also very high in soluble fibre, a type of fibre that attracts water and turns into a gel-like substance during digestion, making you feel fuller for longer and stabilising blood-glucose levels. At the same time, it may also decrease total cholesterol and helps clean out the digestive tract. For this reason, chia seeds are often used to manage constipation, bloating and irritable bowel syndrome (IBS).
Read: What is constipation?
In a study done by Gayathri Balakrishnan from the University of Florida, it was shown that incorporating chia seeds into your diet as a source of fibre may promote and enhance satiety over time by increasing fullness long after a meal.
These seeds also make an excellent substitute for gelatine or corn starch in cold desserts and stews. As milled flour, they add moisture to baked goods and can even be used as an egg replacement in some recipes.
We see them on our burger buns and seed loaves, and many of us use sesame oil in Asian cooking. In addition to essential omega-6 oils, sesame seeds are rich in various minerals, including iron and magnesium.
Sesame seeds are also exceptionally rich in a group of compounds called lignans. These plant molecules are present in many foods, but sesame seeds contain exceptionally high quantities. Lignans function as antioxidants known to help inhibit the process of atherosclerosis (thickening of the artery walls). It may also lower the risk of certain types of cancers, specifically the hormone-related breast and prostate cancers, and may contribute to increased brain function. Lignans have also shown promising effects in other health conditions such as diabetes and inflammation.
Read: Inflammation – the unseen enemy
Sesame seeds are a good source of calcium. According to Manfred Urs Koch in Laugh with Health: The Complete Guide to Health, Diet, Nutrition and Natural Foods, sesame seeds are the ideal non-dairy calcium food. Not only do they provide more calcium than cheese, but they contain no cholesterol. As a matter of fact, they actually lower blood-cholesterol levels through their phytosterol and high fibre content. Among all the seeds and nuts, sesame seeds contain the highest amount of phytosterols, which is good news for those of us with high cholesterol.
The humble flaxseed, or linseed, is one of the most versatile and value-for-money seeds. They’re an excellent source of protein and soluble fibre, and are best known as a rich source of alpha-linolenic acid, an essential omega-3 fatty acid. For this reason, they’re a favourite among vegetarians and those who dislike anything fishy. Incorporating just two tablespoons of flaxseed into your daily diet is a sure-fire way to get all of the omega-3s you need.
Similar to sesame seeds, flaxseeds contain lignans, an excellent source of plant oestrogens and antioxidants, which have potential anti-cancerous and cardio-protective properties. Due to their low carbohydrate and high protein and fibre content, flaxseeds have also been shown to stabilise blood-glucose levels, which may aid in the management of diabetes, according to a study published in the Journal of dietary supplements. What’s more, flaxseeds are also great for preventing constipation and bloating, promoting optimum gut health.
Read: Banish the bloat
Flaxseeds are often used whole in seed loafs. But, grounded up, they’re even better. If you don’t grind the seeds, they can pass through your body undigested, which means you’re not absorbing the essential nutrients from the seed. Ground flaxseeds are commonly used as a low-carbohydrate substitute for wheat in baked products. You’ll find that it’s used in many of grain-free bread and cracker recipes, where the flaxseed powder replaces some of the flour. It’s also commonly used as an egg substitute.
Pumpkin seeds not only make bread look more attractive, they’re also extremely healthy. These seeds are a tasty source of protein, B vitamins, iron and zinc, and provide much magnesium – a mineral used in more than 300 biochemical reactions in the body. Pumpkin seeds also contain omega-6 essential fatty acids, and are rich in antioxidants and fibre.
Some reports show pumpkin seeds can improve symptoms of prostate enlargement and urinary disorders. Research suggests they promote overall prostate health by reducing the uptake of the hormone DHEA (di-hydro-epi-androstenedione), which has been linked to the development of gonadoblastoma – a rare, benign tumour that has cancerous potential. Furthermore, pumpkin seeds may provide anti-hypertensive and heart-protective effects.
Pumpkin seeds may also have anti-depressive and anti-anxiety properties. In a research paper by Shemi George and co-authors, published in the International Journal of Pharma Medicine and Biological Sciences in 2012, it was found that pumpkin seeds could reduce depression because they contain L-tryptophan, a highly concentrated amino acid that is a serotonin precursor. Many athletes use pumpkin seeds quite liberally as a source of magnesium and, of course, protein.
Read: Protein facts
Raw or roasted, they make for the perfect, high-fibre snack. Be sure to eat them whole with the shells. Add them to trail mixes, muesli and healthy baked products, or use these seeds as a garnish for salads and soups.
These seeds are very popular worldwide and are used to add flavour and texture to all kinds of dishes, particularly when dehulled and roasted. That said, they’re much healthier when eaten raw, as their fatty-acid profile remains intact.
Other than that, sunflower seeds are a good source of fibre, folic acid and vitamins B and E. According to Nuts and Seeds in Health and Disease Prevention by Victor R. Preedy et al., organic sunflower seeds are an excellent source of vitamin E, which is the body’s primary soluble antioxidant. As an antioxidant, it plays a role in the prevention of cancer and cardiovascular disease. It also provides anti-inflammatory effects in the body.
Sunflower seeds are a good source of selenium, a trace mineral that plays a role in preventing cell damage and regulating metabolism.A handful of sunflower seeds make for a great, filling snack. These seeds are delicious raw or roasted, and are generally more affordable in comparison to other seeds. Pop them into muesli, trail mixes and seed loaves, or give them a roast and add them to salads or stir fries for crunch.
A word of warning
There have been several reports of intestinal obstruction due to seeds like chia, flax and even pumpkin seeds. This proves that you can get too much of a good thing! As with most things in life, practise moderation, but do enjoy seeds as part of a balanced, healthy diet.
Weekly tip - Sesame seeds packed with calcium
Sesame (Sesamum indicum)
The magic of Chia
- Balakrishnan, G. 2012. Influence of Chia Seeds on Satiety (Doctoral dissertation, University of Florida).
- George, S., & Nazni, P. 2012. Antidepressive Activity of Processed Pumpkin (Cucurbita Maxima) Seeds on Rats. International Journal of Pharma Medicine and Biological Sciences, 1(2), 225-231.
- Koch, M. U. 2011. Laugh with Health: The Complete Guide to Health, Diet, Nutrition and Natural Foods. Exisle Publishing.
- Mani, U. V., Mani, I., Biswas, M., & Kumar, S. N. 2011. An open-label study on the effect of flax seed powder (Linum usitatissimum) supplementation in the management of diabetes mellitus. Journal of dietary supplements, 8(3), 257-265.
- Preedy, V. R., Watson, R. R., & Patel, V. B. (Eds.). (2011). Nuts and seeds in health and disease prevention. Academic press.
Image: Sunflower seeds from Shutterstock