Flaxseed Pro and Con

[SunnySmile501]

There has been some discussion about the benefits and risks of flaxseed and flaxseed oil. Since most that have researched the benefits have only seen what is posted on websites selling flax products. I am starting this thread to have a central location for research both pro and con.

[SunnySmile501]

From the Mayo Clinic

http://www.mayoclinic.com/health/flaxseed/ns_patient-flaxseed
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Flaxseed and its derivative flaxseed oil/linseed oil are rich sources of the essential fatty acid alpha-linolenic acid, which is a biologic precursor to omega-3 fatty acids such as eicosapentaenoic acid. Although omega-3 fatty acids have been associated with improved cardiovascular outcomes, evidence from human trials is mixed regarding the efficacy of flaxseed products for coronary artery disease or hyperlipidemia.
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As a source of fiber mucilage, oral flaxseed (not flaxseed oil) may possess laxative properties, although only one human trial has been conducted for this indication. In large doses, or when taken with inadequate water, flaxseed may precipitate bowel obstruction via a mass effect. The effects of flaxseed on blood glucose levels are not clear, although hyperglycemic effects have been reported in one case series.

[SunnySmile501]

All Omega-3’s are not created equal. Flaxseed only contains alpha-linolenic acid (ALA). You will notice that most sites promoting flaxseed Omega-3’s will give examples of health benefits of the Omega-3’s, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are from fish oils. Then they make statements about flaxseed being high in Omega-3’s. ALA is not readily converted to DHA and EPA after ingesting. Some people lack the ability to convert ALA to DHA/EPA.

From University of Maryland Medical Center

Omega-3 fatty acids

People with either diabetes or schizophrenia may lack the ability to convert alpha-linolenic acid (ALA) to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the forms more readily used in the body. Therefore, people with these conditions should obtain their omega-3 fatty acids from dietary sources rich in EPA and DHA. Also, individuals with type 2 diabetes may experience increases in fasting blood sugar levels while taking fish oil supplements. If you have type 2 diabetes, only use fish oil supplements under the supervision of a health care provider.

Although studies have found that regular consumption of fish (which includes the omega-3 fatty acids EPA and DHA) may reduce the risk of macular degeneration, a recent study including 2 large groups of men and women found that diets rich in ALA may substantially increase the risk of this disease. More research is needed in this area. Until this information becomes available, it is best for people with macular degeneration to obtain omega-3 fatty acids from sources of EPA and DHA, rather than ALA.
Similar to macular degeneration, fish and fish oil may protect against prostate cancer, but ALA may be associated with increased risk of prostate cancer in men. More research in this area is needed.

[SunnySmile501]

These risks are for women, especially pregnant women.

Flaxseed Oil Consumption Raises Premature Birth Risk If Consumed During Last Two Trimesters

Article Date: 31 Oct 2008 - 3:00 PDT

Flaxseed Oil Consumption Raises Premature Birth Risk If Consumed During Last Two Trimesters

A study has found that the risks of a premature birth quadruple if flaxseed oil is consumed in the last two trimesters of pregnancy. The research was conducted by Professor Anick Bérard of the Université de Montréal's Faculty of Pharmacy and the Sainte-Justine Hospital Research Center and Master's student Krystel Moussally.

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The most consumed natural health products by pregnant women are chamomile (19 percent), green tea (17 percent), peppered mint (12 percent), and flaxseed oil (12 percent). Bérard and Moussally correlated these products to premature births and only one product had a very strong correlation: flaxseed oil.

"In the general population, the average rate of premature births is 2 to 3 percent. But for women consuming flaxseed oil in their last two trimesters that number jumps up to 12 percent," says Bérard. "It's an enormous risk."
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From Women’s Health Omega-3 fish oil | flaxseed oil
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Some doctors say that pregnant women should avoid flaxseed oil and/or flax seed supplements as they can have an effect upon estrogen and hormones.

If you are a postmenopausal stage of life then flax seed can be a good way to help you get more of the good fats in your daily diet, while also helping to balance your hormones.
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Flaxseed oil does have omega-3 in it and is preferred by some people however some doctors say flaxseed oil should not be taken by pregnant women.

The reason is that flax seed, like soy or even more so, seems to have an effect on estrogen and hormones and might interfere with your body during pregnancy. Ask your doctor.

One study on this was: Brooks JD, Ward WE, Lewis JE, et al. Supplementation with flaxseed alters estrogen metabolism in postmenopausal women to a greater extent than does supplementation with an equal amount of soy. Am J Clin Nutr 2004;Feb, 79(2):318-325.

Also, flaxseed oil does not have as high an amount of DHA as fish oil, so fish oil is just better anyway at giving you the DHA you want.
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[Zarabelle]

Blimey! I have never seen any negatives before so thanks for starting a neutral thread. Are you against it then?

[not2late]

Here's another link:
Gaia Research - Flaxseed Lignans & The Immune System

Cyanogenic Glycosides
Flaxseed is increasingly being used in some food products because of its high content of alpha-linolenic acid and dietary fibre. However, flaxseed contains cyanogenic glycosides, which release toxic hydrogen cyanide in the presence of water (autohydrolysis). (Chadha R, et al (Food Research Division, Bureau of Chemical Safety, Ottawa, Ontario, Canada), Food Addit Contam, 12: 527, 1995) Cyanogenic glycosides (linamarin, linustatin, neolinustatin) were highest in extracted flaxseed mucilage. We conclude that up to 50 g high-alpha-linolenic acid flaxseed is palatable, safe and may be nutritionally beneficial in humans by raising n-3 fatty acids in plasma and erythrocytes and by decreasing post-prandial glucose responses. Cunnane S, et al, (University of Toronto, Toronto, Canada) Br J Nutr, 69:443, 1993)
The presence of cyanogenic glycosides and diglucosides in flaxseeds is a concern, as they may release cyanide upon hydrolysis. In addition, the polyunsaturated fatty acids may undergo thermal or auto-oxidation (rancidity) when exposed to air or high temperatures that are used in food preparation (& needed to detoxify the cyanogenic glycosides in the mucilage). Cyanide levels produced as a result of autolysis, are below the harmful limits to humans (remember however that “the dose maketh the poison”). (Wanasundara P & Shahidi F, Adv Exp Med Biol, 434: 307, 199

Cyanogenic Glycosides in Flaxseed
By Robin J. Marles, Ph.D.

The presence of cyanogenic glycosides in the diet is significant only in relation to dose and the nutritional status of the consumer. Flax seed meal contains two cyanogenic glycosides, linustatin and neolinustatin. Many foods are slightly cyanogenic (e.g. wheat and barley!), probably as an evolutionary adaptation to discourage herbivory, and our body has a limited capacity to detoxify low concentrations of cyanide through addition of sulphur (from amino acids) to form thiocyanate or reaction with cysteine directly to form beta-cyanoalanine. Thus if the dietary levels of sulphur-containing amino acids are high the body can resist a low intake of cyanide, but if the diet is low in protein overall or due to imbalances in vegetable protein amino acid composition it is low in the sulphur-containing amino acids, then we see toxicity.
The two most common symptoms of chronic cyanide intoxication are goitre, probably caused by high levels of thiocyanate formation where dietary protein levels are adequate and the detoxification mechanism is operating in high gear but the body can't clear the thiocyanate product quickly enough, and fibrocalculous pancreatic diabetes associated with protein malnutrition, where toxicity is probably directly due to cyanide because of the lack of adequate detoxification. Few of us are likely to consume significant quantities of flax seed, nor are those people consuming flax seed likely to have protein malnutrition.
Robin J. Marles, Ph.D.

The prior article on this website gave a figure of heating the flax to 375 degrees F for 15 minutes to deactivate the cyanide compounds.

[SunnySmile501]

Generic risks of flaxseed, plus FDA claims

Possible risks of flaxseed

Flaxseed oil health benefits information from iVillage Total Health

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When consuming any food high in fiber, including flaxseed, it is important to drink ample amounts of calorie- and caffeine-free liquids to prevent intestinal blockage or a worsening of constipation. In addition, the fiber in flaxseed may interfere with the body’s absorption of certain medications. Flaxseed should not be taken at the same time as other medications or supplements.

Flaxseed may not be appropriate for people in certain circumstances, including:




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• Women with hormone-sensitive conditions. The estrogen-like effects of the lignans in flaxseed may not be appropriate for women with endometriosis, polycystic ovary syndrome, uterine fibroids, or cancers of the breast, uterus or ovary.

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• Pregnant or breastfeeding women. Although there is little scientific evidence regarding the effects of flaxseed on pregnant or breastfeeding women, the use of flaxseed in these circumstances is not recommended. Its hormonal effects may stimulate menstruation or otherwise be harmful during pregnancy.
• People who may be harmed by increased bleeding. Certain omega-3 fatty acids produced in the body after consumption of flaxseed may increase the risk of bleeding, which may be dangerous for people on anticoagulant medications or those with a history of bleeding disorders.

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FDA Health Claims For Flaxseed

No health claims or qualified health claims have been approved by the U.S. Food and Drug Administration (FDA) that associate the consumption of flaxseed or flaxseed oil with a reduced risk of any type of disease or medical condition.

Health claims have been approved for fiber, a component of flaxseed. These may be considered dietary guidance claims because they involve broad statements of health benefits for an entire food group. These claims do not apply to flaxseed oil or flaxseed supplements because they do not contain fiber. The FDA-approved health claims concerning fiber are:

• Fiber and cancer risk. Diets low in fat and rich in fiber-containing ingredients may reduce the risk of some types of cancer.

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• Fiber and cardiovascular disease. Fruits, vegetables and grain products that contain at least 0.6 grams of soluble fiber per serving and are low in saturated fat, cholesterol and total fat, may lower the risk of heart disease.

The FDA approved qualified health claims for the types of omega-3 fatty acids found in some fish – eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) – and the risk of coronary heart disease. The claims apply to conventional foods (e.g., salmon, herring) that contain EPA and DHA, or fish oil supplements with EPA and DHA. Because flaxseed and flaxseed oil contain the omega-3 fatty acid known as alpha-linolenic acid, but not EPA or DHA, these qualified health claims do not apply to flaxseed, flaxseed oil or flaxseed supplements. The FDA recommends that people do not exceed more than a total of 3 grams per day of EPA and DHA omega-3 fatty acids, with no more than 2 grams per day from a dietary supplement.

[SunnySmile501]

Originally Posted by Zarabelle

Blimey! I have never seen any negatives before so thanks for starting a neutral thread. Are you against it then?

The jury is still out for me. I had never read anything negative until I started doing research for my book. The lawyer in me is insisting I check as many sources as possible to get the full story before making my decision. One thing is sure, the risks I have found so far from reliable sources needs to be known, especially by women in childbearing years.

[sadie147]

Wow thanks for doing that research Sunny!

It can be very hard to find unbiased studies. The minute you type flax benefits or information into a search engine it's basically just sales pitches/company sponsored studies.

Originally Posted by SunnySmile501

The jury is still out for me. I had never read anything negative until I started doing research for my book. The lawyer in me is insisting I check as many sources as possible to get the full story before making my decision. One thing is sure, the risks I have found so far from reliable sources needs to be known, especially by women in childbearing years.

These are the risks i'd seen in my research i had done too...and for me it was enough to stop eating it daily. I now occaisionaly use it added to my baking, but mostly just to up the fibre. But that's rare.

I've found chia/Salba to be a good alternative (though a bit more pricey..but I don't use nearly as much). I've researched this as well and haven't really found anything negative yet.

Women with hormone-sensitive conditions. The estrogen-like effects of the lignans in flaxseed may not be appropriate for women with endometriosis, polycystic ovary syndrome, uterine fibroids, or cancers of the breast, uterus or ovary.

This is what worries me most. I feel the same way about processed soy products, and I do try to avoid them as well and stick with Almond Breeze milk, though i've had to give in to soy milk occaisionally when the other is not available.

[Sherri]

Great information Sunny, Thank you for sharing.
I've been curious if there is a link between keeping my thyroid levels stable and eating flaxmeal. I hadn't had a problem keeping levels stable until I started eating flaxmeal nearly 2 years ago. Is there a connection between the two?
Any thought or info on that?
Thanks again Sis, Sherri