Ask a Flax Expert
Flax and Your Health
Q. What are the health benefits of flaxseed?
A: Flaxseed contains several disease-fighting compounds, primarily the omega-3 fatty acid, alpha-linolenic acid (ALA), fibre, and lignans. Flaxseed is one of the richest sources of ALA, an omega-3 polyunsaturated fat that offers unique heart health benefits. Flaxseed is an excellent source of both soluble and insoluble fibre, providing three grams of fibre per tablespoon. It also is packed full of lignans, natural cancer-preventative phytonutrients, and vitamins and minerals such as folate, vitamin E, vitamin B-6, copper, zinc, magnesium, and (dry ounce for ounce) more potassium than seven bananas. Flaxseed has been shown to help reduce the risk heart disease, reduce symptoms of inflammatory disorders, protect against some cancer symptoms, reduce cholesterol, and even ease the effects of type 2 diabetes. Learn more about the health benefits of flaxseed and make it an important part of your daily diet.
Q. What is so beneficial about omega-3 fatty acids?
A: The majority of Western diets no longer contain the amount of omega-3 fatty acids needed for overall health and wellness. Today, we are consuming more than 10 times as many omega-6 fatty acids as we are omega-3 fatty acids because of the increase of highly processed foods in modern diets. Linoleic acid is an essential omega-6 fatty acid required by the body in moderate, not excessive, amounts. It is the primary fat in soybean and corn oils. Eating less omega-6 and more omega-3 fats, from foods like ALA-rich flaxseed, can help lower the risk of chronic diseases like heart disease, stroke, and cancer, as well as lower LDL "bad" cholesterol. In fact, large scale studies confirm that plant-derived omega-3's offer unique heart-healthy benefits. Recently, scientists have discovered that flaxseed may play an important anti-inflammatory role in reducing immune system diseases. Flaxseed ALA has been shown to lower blood levels of a compound called C-reactive protein (CRP). Reducing this inflammatory compound appears to be as important as lowering LDL-cholesterol in lowering the risk of heart attacks and strokes.
Q. How much ALA does flaxseed contain compared to other food sources?
A: As shown in the following table, flaxseed is the richest source of ALA in comparison to other foods found in the North American diet.
|Food Item||Average content %|
Q. Does flaxseed contain protein?
A: Flaxseed is a great source of plant-based protein. The protein found in flaxseed is very similar to that of soybean protein, which is considered one of the most nutritious plant proteins. This is attributed to the type of amino acids present, which are the building blocks of protein. Flaxseed contains numerous “essential amino acids”, which the body cannot produce and therefore must obtain from the diet. This is of significance to vegetarians relying on plant sources to meet their daily protein requirements.
Q. What are lignans?
A: Lignans are natural antioxidants that reduce the activity of cell-damaging free radicals, slow the aging process, and increase overall wellness. Flaxseed contains up to 800 times more lignans than other plant sources, such as whole grains and legumes. Besides acting as antioxidants, lignans are phytoestrogens — active substances derived from plants that mimic the action of estrogen hormones in the body. Research continues to show the potential of lignans for treating menopausal symptoms without traditional drugs and reducing the risk of hormone-sensitive cancers of the breast, prostate, and endometrium. Lignans are especially important for women as studies have shown that they may decrease the risk of breast cancer, as well as minimize cancer symptoms, and reduce the spread and growth of breast cancer after diagnosis. Lignans also possess powerful antioxidant and anti-inflammatory properties associated with a lower risk of artery-clogging plaques. Lignans also have been found effective in lowering the risk of type 1 and 2 diabetes.
Q. What's the difference between omega-3 fatty acids from flaxseed and those found in fish oil?
A: Flaxseed is very high in the omega-3 fat alpha-linolenic acid (ALA). This is an "essential" omega-3 fat because our bodies are not able to produce it and we must consume it in our diets from sources like flaxseed. Other omega-3 fats, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), found in marine sources such as fish, krill and algae, are vital for health, but are not considered "essential” because our bodies can make them from ALA. All of these omega-3 fatty acids help decrease inflammation, which is a trigger for heart disease, diabetes, cancer, and arthritis. Flaxseed is unique in that it also is a rich source of lignans, a type of phytoestrogen that may reduce the risk of cancer, as well as a rich source of fibre, which lowers cholesterol and maintains digestive health. Although fish does not have lignans and fibre like flaxseed, it is a good source of protein. Fish can contain traces of mercury, and the Food and Drug Administration (FDA) and Health Canada advise women who are pregnant, nursing, or may become pregnant, as well as young children, to avoid eating certain fish. As a plant food, flaxseed is also advantageous over fish sources of omega-3 fatty acids due to concerns regarding the limited global availability, high cost, allergenicity, and sustainability of seafood products.
Q. Are there any permitted health claims for flaxseed?
A: In 2014, Health Canada approved a health claim linking ground whole flaxseed to blood cholesterol lowering, a major risk factor for heart disease. The claim – only one of eleven approved in Canada - was based on evidence that flaxseed intake can decrease total cholesterol by 0.6 to 9 percent and LDL “bad” cholesterol by 3.4 to 14.9 percent. These reductions in cholesterol are related to a one to 18 percent decrease in heart disease risk. To achieve the maximum heart health benefits, it is recommended that we consume 5 tablespoons (40 g) of ground whole flaxseed over three eating occasions in the day.
Q. How does flaxseed reduce the risk of heart disease?
A: The ALA, lignans and fibre components in flaxseed promote heart health. Dietary intake of ALA is associated with lower risk of having a heart attack or stroke, helps to maintain a stable heartbeat, and reduces the formation of dangerous blood clots. Lignans act as antioxidants to protect against the development of heart disease and improve blood pressure. The dietary fibre in flaxseed helps to decrease the risk of heart disease by reducing total cholesterol and LDL “bad” cholesterol.
Q. Does flaxseed reduce the risk of cancer?
A: Flaxseed is the richest source of lignans, a type of phytoestrogen that have cancer preventive properties. Prostate and breast cancer are leading types of cancer in men and women, respectively. Sex hormones (estrogen and testosterone) play important roles in the development and spread of these cancers. Lignans can beneficially alter the activity of estrogen and testosterone in our bodies to help reduce the risk of hormone-related cancers. The antioxidant properties of lignans also can reduce inflammation. Inflammation is to cancer like fuel is to fire. The ALA in flaxseed also may provide anti-inflammatory effects. Regular consumption of flaxseed increases dietary fibre intake. Diets high in fibre are associated with reduced risk of death due to cancer. For individuals diagnosed with cancer, flaxseed does not appear to interact with drug therapy.
Q. Can people with diabetes eat flaxseed?
A: Yes. Flaxseed is packed with nutrients that help in the fight against diabetes. Flaxseed lignans and fibre protect against the development of diabetes and assist those with diabetes in controlling their blood sugar levels. Dietary intake of ALA is associated with a modest reduction in diabetes risk and may help to increase insulin sensitivity.
Q. I am trying to lose weight. Can I eat flaxseed?
A: Yes. While the caloric content is relatively high for flaxseed due to its oil content, flaxseed may actually help promote weight management. Consumption of nutrient-rich, high fibre foods such as flaxseed contribute to satiety and may help with weight loss or, possibly more importantly, preventing weight gain. Flaxseed also can help improve your health while you are losing weight by decreasing blood cholesterol levels and inflammation.
Q. Does flaxseed contain gluten?
A: No. Sources of gluten include wheat, barley and rye. People diagnosed with celiac disease or gluten intolerance need to eliminate gluten from their diet. Flaxseed is permitted on a gluten-free diet.
Q. How much fibre should I consume each day?
A: The recommended intake of total dietary fibre is 25 g/day for women and 38 g/day for men. Soluble fibre can lower blood cholesterol levels, while insoluble fibre moves the stool through the colon more quickly, helping bowel movements. In spite of the health benefits of fibre, average intake among Canadians is only about half the recommended amount and about 90% of the U.S. population does not consume enough fibre. Flaxseed contains both soluble and insoluble fibre. Two tablespoons of flaxseed provides about 4 g of total dietary fibre – a significant amount to boost your daily fibre intake!
Q. What is the recommended amount of omega-3 fatty acids?
A: The Institute of Medicine set the Adequate Intake of ALA at 1.6 g/day for men and 1.1 g/day for women, or 0.6-1.2% of energy intake, with a dietary omega-6 to omega-3 ratio of 5:1 to 10:1. However, the consumption of this essential fatty acid is very inadequate in North America with approximately 41% of adults not meeting the Adequate Intake for ALA. No recommended intake level has been set by the Institute of Medicine for the omega-3 fatty acids EPA or DHA. The reason for this is that ALA is the only true "essential" omega-3 fatty acid in our diet. An essential nutrient (like ALA) is one that must be obtained from foods because our bodies cannot make it. Because EPA and DHA can be made from ALA, they are not considered "essential" nutrients in the strictest sense. Eating 5 g of flaxseed oil (less than a tablespoon) or 8 g of milled flaxseed (one tablespoon) daily provides enough ALA to meeting the Adequate Intake.
Q. How does flaxseed benefit athletes and sports training?
A: The omega-3 fatty acid, alpha-linolenic (ALA), is an essential fatty acid found in flaxseed that helps to improve the metabolism of fats, which is especially helpful for endurance sports, such as marathons. When a runner "hits the wall" and their glycogen stores are used up, the body begins burning fats. In this case, efficient burning of fats makes a difference in performance. ALA also improves response time. Electrical impulses move from the brain to muscles across cell membranes, which are rich in ALA when consumed in the diet. Omega-3 fatty acids, such as ALA, are the most efficient fatty acids in allowing these electrical impulses to move from cell to cell. Thus, response time is improved. ALA also aids in muscle repair at the cellular level. Omega-3 fatty acids present on the cell membrane significantly affect the speed and quality of tissue repair.
Q. How does flaxseed promote healthy, radiant skin?
A: Flaxseed has a unique and healthy fatty acid profile in the oil with 57 percent as ALA, giving the seed a very favourable omega-6 to omega-3 ratio of 0.3:1. Flaxseed therefore provides a very important source of omega-3 for skin health. Flaxseed naturally contains a very active and stable antioxidant system that protects its oil content of ALA. The antioxidant system in flaxseed represents the interaction of a group of compounds working synergistically. Flaxseed contains several bioactive compounds such as lignans, phenolic acids, anthocyanin pigments, several flavonols and flavones, and phytic acid – all known to have antioxidant activity. These powerful antioxidants can reduce the activity of cell-damaging free radicals that are generated through oxidation in the body and thus, can help protect the skin from damage.
Q. I've heard that I need to grind whole flaxseed. Why is that?
A: While whole and ground flaxseed have the same nutritional content your body gets more benefit from ground flaxseed. That's because the goodness in flaxseed is wrapped up in a hard, shiny seed coat that's hard to crack, even with careful chewing. Grinding or roasting flaxseed breaks this seed coat making all the nutrients easier to digest. Flaxseeds are easy to grind at home using a coffee grinder, food processor or blender. You also can buy ground or "milled" flaxseed in most stores where whole flaxseed is sold.
Q. Is there a difference between flaxseed and flaxseed oil?
A: Yes. Flaxseed oil is the purified fat that results from the cold-pressing of flaxseeds. Because it is the fat portion of the seed, it contains high levels of omega-3 ALA (55-58 percent on a per weight basis in comparison to 18-23 percent from whole or milled seed). Flaxseed oil doesn't have the fibre and protein found in the rest of the seed. Some flaxseed oil manufacturers do “add” back in the lignans – check the label for these products. If the label doesn’t identify lignans, they are not present.
Q. What is flaxseed oil and what types are available?
A: Flaxseed oil results from pressing the oil from the seed. There are two types of flaxseed oil available — conventional and organic. These types of flaxseed oil differ in the way the seed is grown, but the nutritional content is the same.
Q. How much flaxseed should I eat each day?
A: To get the full health benefits of flaxseed, we recommend eating 2 tablespoons (about 16 g) of ground flaxseed per day. If you are concerned about, or have been diagnosed with, high blood cholesterol levels, Health Canada recommends eating 5 tablespoons (40 g) of ground whole flaxseed over three eating occasions in the day.
When using ground flaxseed, because of its high fibre content, increase the amount you eat slowly, starting with about one-half to one tablespoon per day and working up to the higher levels.
Q. Is flaxseed safe for children and toddlers?
A: Flaxseed is a natural plant source of vital nutrients and is considered safe for healthy people of all age groups. We recommend no more than one-quarter tablespoon daily for young children.
Q. What is the nutrient profile of ground flaxseed and flaxseed oil?
A: On average, Canadian flaxseed contains 41% fat (23% as ALA), 20% protein, and 28% total dietary fibre. A detailed nutrient breakdown of flaxseed and its oil is found in the below table.
|Form of Flax||Weight (g)||Common Measure||Energy (kcal)||Total Fat (g)||ALA (g)||Protein (g)||CHO (g)||Dietary Fibre|
|Ground Seed||130||1 cup||585||53.0||30.0||26.0||38.0||36.0|
|Ground Seed||8||1 tbsp||36||3.3||1.8||1.6||2.3||2.2|
|Ground Seed||2.7||1 tsp||12||1.1||0.6||0.5||0.8||0.8|
|Flaxseed Oil||14||1 tbsp||124||14.0||8.0||-||-||-|
|Flaxseed Oil||5||1 tsp||44||5.0||2.8||-||-||-|
Q. How can I add flaxseed into my diet?
A: Flaxseed is added to many products on today's grocery shelves because of the omega-3 fats, lignans, and fibre found in the seed, all of which help deliver a unique and nutritious health boost that aids in overall wellness.
Here are some ways to use flax:
- Whole flaxseed. Whole flaxseed adds colour and crunch to foods. You can sprinkle flaxseeds on top of home baking or mix them into dough. However, to obtain maximal benefits from flaxseed, you should grind them first because whole seeds will pass through your body undigested.
- Milled (ground) flaxseed. Grinding whole seeds breaks their tough outer shell, creating a light coloured powder. Milled flaxseed is available for purchase, or you can make your own in a coffee grinder, blender, or food processor. Making your own has the added benefit of maximizing freshness. Milled flaxseed can be sprinkled on cereal, or add it to doughs, batters, casseroles, and other cooked foods. Mix some into your salad dressing or in your fruit and cottage cheese for a crunchy flaxseed punch. Stir it into thicker soups such as lentil or bean varieties or into pasta sauces just before serving. Another option is to use it in burgers, meatloaf, and fish or vegetable patties as a healthy filler.
- Flaxseed oil. Flaxseed oil is sold in bottles. The oil is extracted from whole flaxseeds using a cold-press process especially developed for plant oils. Pour flax oil on fresh salads. The amount of omega-3 alpha-linolenic acid is higher in purified flaxseed oil than whole flaxseed, but the oil does not contain the beneficial fibre or lignans.
- Gel capsules. Flaxseed oil is sealed in gel capsules and sold as a dietary supplement. Please follow the manufacturers’ recommended dosages.
- Omega-3-enriched eggs. These eggs contain extra omega-3 fatty acids from flaxseed fed to laying hens. You can use omega-3 eggs wherever you would use regular eggs – there’s no taste or functionality difference, only nutritional enrichment.
- Omega-3-enriched foods. These foods, such as yogurt and milk, may contain flaxseed oil, while baked goods, such as breads, can include milled or whole flaxseed.
Check out our healthy recipes for more ideas!
Q. Can omega-3-enriched eggs help me meet the recommended dietary intake for ALA?
A: Hens are fed flaxseed to produce omega-3-enriched eggs. One omega-3-enriched egg provides on average 0.34 g of ALA and 0.13 g of EPA + DHA. By itself, one omega-3-enriched egg provides about one-quarter to one-half of the Adequate Intake of ALA, depending on your age and gender. If eaten on a regular basis, omega-3-enriched eggs make a substantial contribution to your need for omega-3 fatty acids. While the omega-3 content may vary substantially between different brands, the caloric value and protein content of omega-3-enriched eggs are similar to that of regular eggs.
Q. Is flaxseed organic?
A: There are a few companies that offer organically grown flaxseed, labeling the seeds and oils with an "organic" symbol. The "organic" symbol is a mark which is earned when companies have met the requirements of organic food production. You can expect to pay a premium for organic flaxseed. Any flaxseed that you buy from a reputable retailer is perfectly safe to eat, organic or not.
Q. Is flaxseed genetically modified?
A: No. Genetically modified flaxseed is not legal for sale in Canada or the US. Although a genetically modified flaxseed variety was developed in the 1990s, the variety has been deregistered and ordered destroyed.
Q. Can I eat too much flaxseed?
A: While flaxseed provides numerous health benefits, it is possible to get too much of a good thing. Cooking or baking with flaxseed is a perfectly safe practice. However, when raw flaxseed is added in large quantities to diets that do not contain a healthy mix of foods, health problems can develop. Like thousands of other plant seeds, flaxseed contains moderate amounts of natural compounds called cyanogenic glucosides. In an unbalanced diet containing too much uncooked flaxseed, cyanogenic compounds can build up in the body, leading to unpleasant and, on occasion, life-threatening reactions. Such a buildup has been documented in populations relying solely on a staple such as cassava in their diet. In these cases, the illness-causing deposits were not blocked by enzymes supplied by other foods in the diet. A balanced diet containing 50 g (approximately ¼ cup) of flaxseed daily does not increase glucoside buildup. In addition, cyanogenic compounds are made harmless by cooking.
Q. I am on blood thinners. Can I eat flaxseed?
A: Warfarin (brand name Coumadin®) is a common medication used to prevent blood clots. Since warfarin can interact with some foods and over-the-counter supplements, it is important to tell your doctor about any other medications or supplements that you take. Vitamin K is one of the nutrients with which warfarin can interact. For people taking warfarin, better control of blood clotting is achieved when dietary vitamin K intake remains fairly constant from day to day. The Institute of Medicine has set the Adequate Intake value for vitamin K at 120 µg per day for males and 90 µg per day for females. Flaxseed contains 4.3 µg of vitamin K per 100 g, so the vitamin K content is quite low relative to the recommended intake level. The omega-3 alpha-linolenic content of flaxseed oil has also been suggested to affect the international normalized ratio (INR; a measure of blood clotting) when taking warfarin. However, the research is limited and the amount that may pose a risk is uncertain. If you are taking warfarin, it is best to keep your diet as consistent as possible each day. Flaxseed is a healthy addition to the diet of patients taking warfarin, but should be consumed in moderation and a similar amount should be eaten daily. Patients on warfarin are encouraged to have their INR monitored regularly and to speak with their healthcare professional before making any substantial dietary changes.
Q. I have diverticular disease. Can I eat flaxseed?
A: Diverticulosis is the formation of tiny pockets, called diverticula, in the wall of the large intestine. Many people with diverticulosis do not even know that they have it. However, some people experience symptoms due to diverticular bleeding or diverticulitis (infection of the diverticula). In the past it was recommended that people with diverticulosis avoid seeds, nuts, corn, and popcorn because it was believed these foods might get caught in the diverticula. However, research shows that these foods may actually protect against diverticulitis. Thus, flaxseed is generally considered safe for people with diverticular disease.
A high fibre diet is recommended for people with diverticulosis. Increasing dietary fibre will not result in adverse symptoms in people with existing diverticula and is associated with a decreased risk of developing more pockets. However, fibre will not repair diverticula that are already present. As a fibre-rich food, flaxseed can help boost fibre intake for people with diverticular disease. Increased fibre intake should go hand-in-hand with increased fluid intake. Treatment of acute diverticulitis depends on the severity of the symptoms that may include a low fibre, high fluid diet, but once symptoms improve, dietary fibre intake usually is recommended to be gradually increased.
Q. Does flaxseed help with prostate health?
A: Prostate cancer is a leading type of cancer diagnosed in men. Sex hormones (estrogen and testosterone) play key roles in the development and progression of prostate cancer by increasing production of new cancer cells, spreading the cancer to other organs, and promoting the growth of new blood vessels that support the spread of the cancer. The lignans in flaxseed are a type of phytoestrogen, which can affect the activity of estrogen and testosterone in our bodies and may help to prevent cancers such as prostate cancer.
Flaxseed is a rich source of alpha-linolenic acid (ALA). Some research has suggested that diets high in ALA are associated with increased risk of prostate cancer, but more recent studies have not found this link. More research is still needed to confirm if flaxseed can help to prevent prostate cancer or provide additional therapeutic benefit for men undergoing prostate cancer treatment. If you have prostate cancer or may be at risk of developing the disease, it is advisable to speak to your healthcare professional before increasing sources of plant based omega-3 fatty acids.
Q. Is flaxseed or flaxseed oil safe to consume during pregnancy?
A: The lignans in flaxseed have the potential to exert mild estrogenic effects during pregnancy. Limited evidence from animal studies suggests adverse effects in the offspring of pregnant animals fed diets high in flaxseed. The Natural Health Products Division of Health Canada does not advise of any contraindications during pregnancy or lactation for flaxseed (whole or ground) at doses up to 45 g/day or flaxseed oil up to 32 g (2 tbsp) per day. Flaxseed is a good source of alpha-linolenic acid (ALA), an essential nutrient for women during pregnancy. Until more information is known, a sensible recommendation is for pregnant women to limit their daily intake of flaxseed and flaxseed oil to amounts that achieves the Adequate Intake for alpha-linolenic acid during pregnancy. The Adequate Intake for ALA is 1.4 g/day for pregnant women and 1.3 g/day for lactating women. Approximately 15 ml (1 tbsp, 7 g) of ground flaxseed provides 1.6 g of ALA, and 2.5 ml (½ tsp) flaxseed oil provides 1.3 g ALA.
Q. Does flaxseed contain trans fat?
A: Trans fat increases the risk of heart disease and should be avoided. Trans fat is created when liquid vegetable oils are made into solid fats by a process called hydrogenation. Hydrogenated oils are often used in processed foods because they improve the taste and texture of the food and help keep the food fresher for longer. Flaxseed oil may contain a very tracer level of natural trans fats that do not cause heart disease (as associated with synthetic trans fatty acids). Most of the fat in flaxseed is polyunsaturated, including the heart healthy omega-3 fatty acid alpha-linolenic acid.
Flax in comparison to other Nutritional supplements
Q. Should I take fish or flaxseed oil supplements?
A: There are solid health benefits attributable to both fish and flaxseed oils. The omega 3 fatty acid, alpha-linolenic acid (ALA), in flaxseed oil is entirely different from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fish oil. It is ideal to consume fish and flaxseed as whole foods rather than supplements so that you receive the benefits from the oils as well as the other nutrients found in these foods. In addition to the omega-3 fatty acids, fish provides high quality protein, and flaxseed has lignans and fibre. However, fish and flaxseed oil supplements are good alternatives if the whole foods are not an option due to allergies, taste preference, or convenience. Contamination of fish oils is less of a concern these days with modern refining practices. Good fish oil supplements actually are safer to consume than whole fish which have detectable levels of heavy metals and other contaminants. Extraction of oils from fish eliminates water soluble heavy metals. For most people there is value to consuming both plant (ALA) and animal (EPA and DHA) omega-3 fatty acids, either from the whole foods or supplements.
Q. Which is healthier – flaxseed or chia seed?
A: Chia seed is a whole grain that has been used by humans for centuries. Like flaxseed, chia seeds are high in dietary fibre and alpha-linolenic acid (ALA), with over 50% of its oil content being ALA. The below table shows the nutrient content of chia seed and flaxseed from the Canadian Nutrient File. On a weight basis, flaxseed is higher in omega-3 fatty acids (from ALA) and protein, whereas chia seed is higher in total dietary fibre. Flaxseed is a richer source of lignans than chia, which act as potent antioxidants in the body. The large body of research showing the heart-health benefits of flaxseed has led Health Canada to approve a health claim for flaxseed. No such claims have been approved for chia. Both seeds are healthy additions to your diet, though flaxseed may have some unique advantages.
|Food Item||Average content %|
Q. Why do we need Omega 3 fats from flaxseed?
A: ALA is the true essential omega-3 fatty acid, being required in our diets because our bodies do not make it; the other omega-3 fatty acids like EPA and DHA are not “essential” in the strictest sense because our bodies make them from dietary ALA and tissue stores of ALA. Nonetheless, all omega-3 fatty acids – including ALA, EPA and DHA – are often called “essential fatty acids” because their importance in human nutrition and health is widely recognized.
Q. What are omega-6 fatty acids?
A: Omega-6 fatty acids belong to an entirely different family of fatty acids than the omega-3 fatty acids. The main omega-6 fatty acid in the diet is linoleic acid, which is the essential omega-6 fatty acid, being required in the diet because our bodies do not make it. The main dietary sources of omega-6 fatty acids are vegetable oils like sunflower oil, corn oil and soybean oil and food products made with these oils.
Q. Is the dietary omega-6/omega-3 ratio important?
A: The diet of humans living in the Paleolithic era was rich in omega-3 fatty acids, with a dietary ratio of omega-6 fatty acids to omega-3 fatty acids of about 1:1. Today’s North American diet is high in omega-6
fats and low in omega-3 fats, giving a ratio of upwards of 16:1. Current omega-3 fat intakes may not be optimum for preventing heart disease and other chronic diseases. For this reason, consumers are advised to consume more omega-3 fatty acids and to limit omega-6 fatty acids from sources such as soybean and corn oils.
Q. Is omega-3 fatty acid production sustainable?
A: Current intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the long-chain omega-3 fatty acids found mainly in fatty fish, are about 100 to 200 mg/day. Achieving recommended higher intakes of 500 mg to 1 g of EPA + DHA daily will be challenging on several fronts. Any increase in consumers’ fish intake is likely to place additional pressures on global fish stocks, many of which are overfished. In addition, concerns about the contamination of fish with methylmercury, dioxins, pesticides and other chemicals have led to federal advisories in both Canada and the United States. Finally, many low-income and middle-class families may not be able to afford to buy fatty fish, the main source of EPA and DHA. Compared with seafood, plant-based sources of the essential omega-3 fatty acid alpha-linolenic acid (ALA) are a sustainable, renewable and relatively inexpensive source of essential omega-3 fat. Many consumers may find it easier, more convenient and more environmentally friendly to add a little ground flax or flax oil to the diet than to learn to cook or enjoy the taste of fatty fish.
Q. How healthy are people who do not eat fish or take fish oil supplements?
A: Plants are a source of alpha-linolenic acid (ALA). Many populations do not consume fish relying instead on plant based diets. Full-term infants, for example, obtain an adequate amount of omega-3 fatty acids, including DHA, for brain development from breast milk or enriched infant formula. Furthermore, full-term infants born to vegan and vegetarian women, who typically have low DHA intakes, appear to develop normally and do not exhibit deficits in brain development. Adult vegans and vegetarians, who obtain most or all of their omega-3 fats in the form of ALA-rich plants, are remarkably healthy and have low rates of heart disease and some types of cancer. Plus, plant-based diets are more environmentally friendly, contributing less to green-house gases and requiring fewer energy inputs than meat-based diets.
Q. Do we need to consume more omega-3 fatty acids?
A: Current intakes of omega-3 fatty acids may not be optimal. Most diets only contain about 0.1 to 0.2 g or 100 to 200 mg of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) per day. Some experts recommend higher intakes of all omega-3 fatty acids, based on clinical evidence showing that omega-3 fats help reduce inflammatory reactions, promote the health of blood vessels and reduce the risk of heart attack, stroke and other chronic diseases. Higher ALA intakes of 2 g to 3 g per day have been proposed. An intake of 500 mg of EPA + DHA daily has been recommended to reduce risk of heart disease. For people with existing heart disease, an intake of 1 g (1000 mg) of EPA + DHA daily is recommended.
Q. I’ve heard coconut oil is the new superfood and can help with weight loss, even though it’s high in saturated fat. Is this true?
A: There are many misconceptions regarding the health effects of coconut oil which is extracted from the kernel of coconut palm. Coconut oil is mostly (91%) saturated fat. Because of its high saturated fat content it is slow to oxidize making it resistant to fatty acid “breakdown”. As such it is commonly used in cooking, especially for frying.
The majority of the saturated fat in coconut oil is lauric acid. The structure of this type of fat is called a “medium chain triglyceride (MCT)”. Lauric acid and other MCTs are digested and handled by the body in a different way than most fats that are “long chain” (i.e. polyunsaturated fatty acids). Oils with MCTs provide quick energy for the body and therefore may be less likely to be stored as body fat. MCTs are a source of “quick” fuel and appear to behave more like a carbohydrate than a fat (Assuncao et al. 2009. Lipids. 44:593–601).
Much of this research is very preliminary and still needs to be confirmed in further clinical studies. Some health professionals argue that the studies being performed are for short periods of time, the number of study participants is too small, and many of the results stated have not been significant enough to prove any benefit to coconut oil consumption. And since coconut oil, like all oils is high in calories, it is premature to recommend it as a part of a weight loss diet.
Overall, the fatty acid profile of coconut oil is not deemed as healthy. In comparison with flaxseed oil which has a high level of the essential fatty acid (EFA), omega 6 linoleic acid (about 16%) and the EFA omega 3 fatty acid alpha-linolenic (ALA, 55-57%), coconut contains no omega 3 and only 3% omega 6 fats. The high levels of saturated fatty acids and very low levels of polyunsaturated fats (the EFAs) can lead to increased risk of heart disease.
Due to its very high saturate levels, many health organizations advise against the consumption of coconut oil, including the United States Food and Drug Administration (https://web.archive.org/web/20140201190357/http:/www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm282425.htm); the World Health Organization (http://whqlibdoc.who.int/publications/2005/9241546727.pdf); the International College of Nutrition (Singh et al. 1996. J Cardiovasc Risk 3 (6): 489); the United States Department of Health and Human Services (Dietary Guidelines for Americans 2010); the American Heart Association (http://newsroom.heart.org/news/no-change-in-aha-recommendations-on-saturated-or-poly-unsaturated-fat); the British National Health Services (http://www.nhs.uk/conditions/coronary-heart-disease/pages/prevention.aspx) and Dietitians and Canada (http://www.dietitians.ca/Your-Health/Nutrition-A-Z/Heart-Health/Healthy-Eating-Guidelines-to-Prevent-Heart-Disease.aspx). These recommendations are made based upon decades of research that have shown a relationship between the intake of saturated fatty acids and an increase in blood cholesterol levels, especially LDL (or "bad") cholesterol levels. Saturated fat consumption has also been linked to higher risks of heart disease and stroke.
Several studies confirm that in contrast to coconut oil, dietary flaxseed inhibits atherosclerosis, the plaque build-up in arteries that can lead to heart disease. Dupasquier et al. (2007. Am J Physiol Heart Circ Physiol 293: H2394) reported that flaxseed has powerful anti-inflammatory actions. In an animal model that closely represents the human atherosclerotic condition, a 10% flaxseed-supplemented diet (FX) was compared to a diet with 5% coconut oil (CS) for 24 wk. The CS mice exhibited elevated levels of plasma cholesterol, triglycerides, and saturated fatty acids and an increase in plaque development. Supplementation of the cholesterol-enriched diet with 10% (wt/wt) ground flaxseed lowered plasma cholesterol and saturated fatty acids, increased plasma ALA, and inhibited plaque formation in the aorta.