Grown since the beginning of civilization, flax seeds are one of the oldest crops. There are two types, brown and golden, which are equally nutritious.
A typical serving size for ground flax seeds is 1 tablespoon (7 grams).
Just one tablespoon provides a good amount of protein, fiber and omega-3 fatty acids, in addition to being a rich source of some vitamins and minerals.
One tablespoon of ground flax seeds contains the following (1):
Protein: 1.3 grams
Carbs: 2 grams
Fiber: 1.9 grams
Total fat: 3 grams
Saturated fat: 0.3 grams
Monounsaturated fat: 0.5 grams
Polyunsaturated fat: 2.0 grams
Omega-3 fatty acids: 1,597 mg
Vitamin B1: 8% of the RDI
Vitamin B6: 2% of the RDI
Folate: 2% of the RDI
Calcium: 2% of the RDI
Iron: 2% of the RDI
Magnesium: 7% of the RDI
Phosphorus: 4% of the RDI
Potassium: 2% of the RDI
Interestingly, flax seeds' health benefits are mainly attributed to the omega-3 fatty acids, lignans and fiber they contain.
2. Flax Seeds Are High in Omega-3 Fats
If you are a vegetarian or don't eat fish, flax seeds can be your best source of omega-3 fats.
They are a rich source of alpha-linolenic acid (ALA), a mostly plant-based omega-3 fatty acid (2Trusted Source).
ALA is one of the two essential fatty acids that you have to obtain from the food you eat, as your body doesn't produce them.
Animal studies have shown that the ALA in flax seeds prevented cholesterol from being deposited in the blood vessels of the heart, reduced inflammation in the arteries and reduced tumor growth (3Trusted Source, 4Trusted Source, 5Trusted Source).
A Costa Rican study involving 3,638 people found that those who ate more ALA had a lower risk of heart attack than those who consumed less ALA (6Trusted Source).
Also, a large review of 27 studies involving more than 250,000 people found that ALA was linked to a 14% lower risk of heart disease (7Trusted Source).
Furthermore, a recent review of observational data concluded that ALA had heart health benefits comparable to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two of the more well-known omega-3 fats (11).
3. Flax Seeds Are a Rich Source of Lignans, Which May Reduce Cancer Risk
Lignans are plant compounds that have antioxidant and estrogen properties, both of which can help lower the risk of cancer and improve health (12Trusted Source).
Interestingly, flax seeds contain up to 800 times more lignans than other plant foods (5Trusted Source).
Observational studies show that those who eat flax seeds have a lower risk of breast cancer, particularly postmenopausal women (13Trusted Source).
Additionally, according to a Canadian study involving more than 6,000 women, those who eat flax seeds are 18% less likely to develop breast cancer (14Trusted Source).
However, men can also benefit from eating flax seeds.
In a small study including 15 men, those given 30 grams of flax seeds a day while following a low-fat diet showed reduced levels of a prostate cancer marker, suggesting a lower risk of prostate cancer (15Trusted Source).
Flax seeds also appeared to have the potential to prevent colon and skin cancers in laboratory and animal studies. Yet, more research is needed to confirm this (16).
Nevertheless, the evidence thus far points to flax seeds being a potentially valuable food in the fight against various cancers.
4. Flax Seeds Are Rich in Dietary Fiber
Just one tablespoon of flax seeds contains 3 grams of fiber, which is 8–12% of the daily recommended intake for men and women, respectively (17Trusted Source).
This fiber duo gets fermented by the bacteria in the large bowel, bulks up stools and results in more regular bowel movements.
On one hand, soluble fiber increases the consistency of the contents of your intestine and slows down your digestion rate. This has been shown to help regulate blood sugar and lower cholesterol (18Trusted Source).
On the other hand, insoluble fiber allows more water to bind to the stools, increases their bulk and results in softer stools. This is useful for preventing constipation and for those who have irritable bowel syndrome or diverticular disease (5Trusted Source).
5. Flax Seeds May Improve Cholesterol
Another health benefit of flax seeds is their ability to lower cholesterol levels.
In one study in people with high cholesterol, consuming 3 tablespoons (30 grams) of flaxseed powder daily for three months lowered total cholesterol by 17% and "bad" LDL cholesterol by almost 20% (19Trusted Source).
Another study of people with diabetes found that taking 1 tablespoon (10 grams) of flaxseed powder daily for one month resulted in a 12% increase in "good" HDL cholesterol (20Trusted Source).
In postmenopausal women, consuming 30 grams of flax seeds daily lowered total cholesterol and LDL cholesterol by approximately 7% and 10%, respectively (21Trusted Source).
These effects appear to be due to the fiber in flax seeds, as it binds to bile salts and is then excreted by the body.
To replenish these bile salts, cholesterol is pulled from your blood into your liver. This process lowers your blood levels of cholesterol (18Trusted Source).
This is definitely good news for those wanting to improve their cholesterol.
A Canadian study found eating 30 grams of flax seeds daily for six months lowered systolic and diastolic blood pressure by 10 mmHg and 7 mmHg, respectively (23Trusted Source).
For those who were already taking blood pressure medication, flax seeds lowered blood pressure even further and decreased the number of patients with uncontrolled high blood pressure by 17% (23Trusted Source).
Furthermore, according to a large review that looked at data from 11 studies, taking flax seeds daily for more than three months lowered blood pressure by 2 mmHg (24Trusted Source).
While that might seem insignificant, a 2-mmHg reduction in blood pressure can lower the risk of dying from stroke by 10% and from heart disease by 7% (25Trusted Source).
7. They Contain High-Quality Protein
Flax seeds are a great source of plant-based protein, and there's growing interest in flaxseed protein and its health benefits. Flaxseed protein is rich in the amino acids arginine, aspartic acid and glutamic acid (26, 27).
Numerous lab and animal studies have shown that flaxseed protein helped improve immune function, lowered cholesterol, prevented tumors and had anti-fungal properties (28, 29, 30Trusted Source).
If you are considering cutting back on meat and worried that you will be too hungry, flax seeds may just be your answer.
In fact, in one recent study, 21 adults were given an animal protein meal or plant protein meal. The study found no difference in terms of appetite, satiety or food intake noted between the two meals (31Trusted Source).
It's likely both the animal and plant protein meals stimulated hormones in the gut to bring about the feeling of fullness, which resulted in eating less at the next meal.
8. Flax Seeds May Help Control Blood Sugar
Type 2 diabetes is a major health problem worldwide.
A few studies have found that people with type 2 diabetes who added 10–20 grams of flaxseed powder to their daily diet for at least one month saw reductions of 8–20% in blood sugar levels (20Trusted Source, 32, 33).
This blood sugar-lowering effect is notably due to flax seeds' insoluble fiber content. Research has found that insoluble fiber slows down the release of sugar into the blood and reduces blood sugar (5Trusted Source, 34Trusted Source).
However, one study found no change in blood sugar levels or any improvement in diabetes management (35Trusted Source).
This might be due to the small numbers of subjects in the study and the use of flaxseed oil. Flaxseed oil lacks fiber, which is credited with flax seeds' ability to lower blood sugar.
Overall, flax seeds can be a beneficial and nutritious addition to the diet of people with diabetes.
9. Flax Seeds Keep Hunger at Bay, Which May Aid Weight Control
If you have the tendency to snack between meals, you might want to consider adding flax seeds to your beverage to stave off hunger pangs.
The feelings of reduced hunger were likely due to the soluble fiber content of flax seeds. It slows digestion in the stomach, which triggers a host of hormones that control appetite and provide a feeling of fullness (37Trusted Source, 38Trusted Source, 39Trusted Source).
Flax seeds' dietary fiber content may aid weight control by suppressing hunger and increasing feelings of fullness.
10. Flax Seeds Can Be a Versatile Ingredient
Flax seeds or flaxseed oil can be added to many common foods. Try the following:
Adding them to water and drinking it as part of your daily fluid intake
Drizzling flaxseed oil as a dressing on salad
Sprinkling ground flax seeds over your hot or cold breakfast cereal
Mixing them into your favorite yogurt
Adding them into cookie, muffin, bread or other batters
Mixing them into smoothies to thicken up the consistency