Appetite suppression
Dietary fiber from flaxseed reduces appetite. Even as little as 3 grams consumed with a meal can reduce appetite and lead to weight loss.

Blood pressure lowering, decrease of hypertension
It appears that taking a flax seed and oil supplement could be useful in those who have hypertension but my preference is to consume whole flax seeds.

J Nutr. 2015. Flaxseed consumption may reduce blood pressure: a systematic review and meta-analysis of controlled trials. The purpose of this study was to clarify the effect of flaxseed consumption on blood pressure. Further, the influence of baseline blood pressure, type of flaxseed supplementation, and duration of flaxseed supplementation on blood pressure was explored. The present meta-analysis suggests that consumption of flaxseed may lower blood pressure slightly. The beneficial potential of flaxseed to reduce blood pressure (especially diastolic blood pressure) may be greater when it is consumed as a whole seed and for a duration of >12 wk.

Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients.
The purpose of the present study was to examine the effect of increased alpha linolenic acid intake on blood pressure in man. We used a prospective, two-group, parallel-arm design to examine the effect of a 12-week dietary supplementation with flaxseed oil, rich in alpha linolenic acid (8 g/day), on blood pressure in middle-aged dyslipidaemic men. The diet of the control group was supplemented with safflower oil, containing the equivalent n-6 fatty acid (11 g/day linoleic acid). Supplementation with flax seed oil resulted in significantly lower systolic and diastolic blood pressure levels compared with linoleic acid.

Hypertension. 2013. Potent antihypertensive action of dietary flaxseed in hypertensive patients. The purpose of the study was to examine the effects of daily ingestion of flaxseed on systolic (SBP) and diastolic blood pressure (DBP) in peripheral artery disease patients. In this prospective, double-blinded, placebo-controlled, randomized trial, patients (110 in total) ingested a variety of foods that contained 30 g of milled flaxseed or placebo each day over 6 months. Plasma levels of the ω-3 fatty acid α-linolenic acid and enterolignans increased 2- to 50-fold in the flaxseed-fed group but did not increase significantly in the placebo group. Patient body weights were not significantly different between the 2 groups at any time. SBP was ≈ 10 mm Hg lower, and DBP was ≈ 7 mm Hg lower in the flaxseed group compared with placebo after 6 months. Patients who entered the trial with a SBP ≥ 140 mm Hg at baseline obtained a significant reduction of 15 mm Hg in SBP and 7 mm Hg in DBP from flaxseed ingestion. The antihypertensive effect was achieved selectively in hypertensive patients. Circulating α-linolenic acid levels correlated with SBP and DBP, and lignan levels correlated with changes in DBP. In summary, flaxseed induced one of the most potent antihypertensive effects achieved by a dietary intervention.

Brain benefit, depression, mood
Doctors generally believe that the best way to treat mood, thought, and memory disorders is with pharmaceutical medicines that directly influence levels of brain chemicals such as serotonin, dopamine, and acetylcholine. Although drugs have very important clinical uses, they are only part of the solution. A comprehensive approach to treating cognitive disorders should include foods and supplements that benefit the overall health of brain cells. These include omega-3 fatty acids found in flaxseed and fish.
   One way to influence brain health through diet is to consume the right fats and oils. About 60 percent of the brain consists of lipids (fats) which make up the lining, or cell membrane, of every brain cell. The types of fats present in the brain influence its structure and function. How well your mind works depends, in the long run, on what you eat.

I have been taking flaxseed oil as per your recommendation in your book Mind Boosters.  I like it better than fish oils because one, I don't get those annoying fish burps, and two I notice a slight mood elevation. 
   Yes, some people notice a mood elevation taking flax seed oil.

Love your site. I discovered Flaxseed oil for me is like regular "meds" are for people with mood swings. No doubt about it. I've been off and on too many times and am now 100% convinced that flaxseed oil is indispensable for leveling the mood especially under stress.

Cancer Inhibitor With a Little Crunch
Researchers at Duke University Medical Center in North Carolina took a look at the seed's role as a food supplement in 161 men who were scheduled to undergo surgery for prostate cancer. Half of the men added 30 grams of flaxseed (about one ounce) to their diets for about 30 days. After the surgery, the researchers looked at the men's tumor cells to see how quickly the cancer had multiplied. The cancer cells in the flaxseed group were growing about 30 to 40 percent slower than in the control group. If you want to get the health benefits of flaxseeds, you can add half a teaspoon or a teaspoon of raw flaxseeds to soups and salads. Or you can take a flaxseed oil supplement in the form of one or two softgels a day. You can find flaxseeds and flaxseed oil in health food stores or online.

Omega-3 fatty acids from fish have a stronger effect than flaxseed and other oils when it comes to cancer prevention.

Cholesterol and blood lipids
Meta-analysis of the effects of flaxseed interventions on blood lipids
Am J Clin Nutrition 2009.
Flaxseed interventions reduced total and LDL cholesterol. Significant reductions were observed with whole flaxseed and lignan supplements but not with flaxseed oil. The cholesterol-lowering effects were more apparent in females (particularly postmenopausal women), and in individuals with high initial cholesterol concentrations. No significant changes were found in the concentrations of HDL cholesterol and triglycerides. Flaxseed significantly reduced circulating total and LDL-cholesterol concentrations, but the changes were dependent on the type of intervention, sex, and initial lipid profiles of the subjects.

Constipation
Without a doubt whole flax seeds make stools softer, larger, and improve problems with constipation.

Cystic fibrosis
BMC Complement Altern Med. 2015. Flaxseed modulates inflammatory and oxidative stress biomarkers in cystic fibrosis: a pilot study. Cystic fibrosis (CF) leads to advanced lung disease despite aggressive care. Persistent inflammation and oxidative stress contribute to exacerbations and disease progression. Flaxseed (FS), a dietary botanical supplement with high fiber, lignan phenolics, and omega-3 fatty acids has anti-inflammatory and antioxidant properties in murine models of acute and chronic lung injury. This pilot study was designed to determine whether CF patients could tolerate FS, evaluate circulating FS metabolites, and study biomarkers of lung damage, as a prelude to studying clinical outcomes. 10 CF patients and 5 healthy volunteers consumed 40 g of flax seed daily for 4 weeks with safety and tolerability being assessed. Urine was evaluated for systemic oxidative stress and plasma for FS metabolites (enterolignans) and cytokine levels. Buccal swabs were analyzed for gene expression of Nrf2-regulated antioxidant enzymes including Heme Oxygenase-1 and NAD(P)H Quinone Oxidoreductase 1 (NQO1). :All subjects completed the study without serious adverse events. Plasma levels of enterolignans were detectable in both healthy controls and CF volunteers. CF patients were stratified based on plasma enterolignan levels after 2 weeks of FS administration into high and low plasma lignan cohorts. The low enterolignan level cohort experienced a statistically significant drop in urinary inflammatory IsoP and plasma TNFα levels, while demonstrating higher average NQO1 mRNA levels in buccal epithelium compared to high-lignan patients. This pilot study demonstrated that FS is tolerated by CF patients. FS metabolites could be detected in the plasma. Future studies will assess appropriate dosing and target populations for FS, while exploring clinical outcomes.

Diabetes
Nutr Res. May 2013. Daily flaxseed consumption improves glycemic control in obese men and women with pre-diabetes: a randomized study.

Heart disease
Flaxseed and cardiovascular risk. Nutr Reviews. 2004.
This plant is a rich source of both alpha-linolenic acid (ALA) and the phytoestrogen, lignans, as well as being a good source of soluble fiber. Human studies have shown that flaxseed can modestly reduce serum total and low-density lipoprotein cholesterol concentrations, reduce postprandial glucose absorption, decrease some markers of inflammation, and raise serum levels of the omega-3 fatty acids, ALA and eicosapentaenoic acid.

Flaxseed and cardiovascular health. J Cardiovasc Pharmacol. 2009.
Flaxseed contains 35% of its mass as oil, of which 55% is alpha-linolenic acid (ALA). Flax meal, which is devoid of oil, contains the lignan secoisolariciresinol diglucoside. Suppression of atherosclerosis is the result of its lignan content and not the result of ALA content.

Flaxseed reverses atherosclerotic lesion formation and lowers lipoprotein(a) in ovarian hormone deficiency. Menopause 2013.
Seventy-two female Golden Syrian hamsters were randomly divided into six groups (n = 12), sham-operated (sham) or ovariectomized (ovx), and kept on the same diet for 120 days to allow for atherosclerotic lesion development. After this 120-day period, whole flaxseed was introduced to the diets of hamsters in three of the groups: group 1 (sham + casein); group 2 (ovx + casein); group 3 (ovx + 7.5% flaxseed); group 4 (ovx + 15% flaxseed); group 5 (ovx + 22.5% flaxseed); and group 6 (ovx + 17β-estradiol). This diet was maintained for an additional 120 days. Lesion regression was examined histologically, and serum was analyzed for total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, Apo A, Apo B, and lipoprotein(a). Results showed that 15% and 22.5% flaxseed, compared with ovx animals, significantly reduced lipoprotein(a) and Apo B. Flax reduced by 67% the number of animals with aortic arch lesions. All three doses of flax reduce the severity of lesion formation compared with ovx controls. These results support the efficacy of flaxseed in reducing cardiovascular disease risk.

Hormone influence
It appears that compounds in flaxseed influence levels of hormones in the body, such as estrogens and perhaps testosterone. The exact nature of this influence is still being evaluated.
   Mice fed plenty of flaxseed seem to be protected against the worst forms of prostate cancer, which suggests flaxseed contains some protective components. Flaxseed is a rich source of omega-3 fatty acids, fiber and compounds known as lignans, all of which may play a role in protecting against cancer and perhaps also heart disease.

I  am just starting to take flax hull lignans. I notice in their product literature that flax hull lignans "reduce serum testosterone". (Maybe estrogen also?). As a health-conscious man I am concerned about this as a reduction in serum testosterone is an important negative factor in male ageing. Could you kindly clarify this issue with me? Also, I have read this, Lignans may reduce the amount of testosterone available due to their ability to increase sex hormone binding globulin (SHBG). This protein binds circulating testosterone.
   There are countless chemical interactions in the body along with countless hormonal influences a the cellular, tissue and organ levels. Focusing on the level of one hormone as a result of a specific food ingestion does not give us the overall health benefits and risks of a particular food. Flax seed supplements are a healthy choice to one's diet. The specific effects of flax seed lignans on hormonal levels in humans has not been well defined and the amount consumed makes a difference.

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.
Phytoestrogens, which are abundant in flaxseed and soy, have chemical structures resembling those of endogenous estrogens and have been shown to exert hormonal effects, thereby affecting chronic diseases. We compared the effects of consuming equal amounts of flaxseed or soy on estrogen metabolism and biochemical markers of bone metabolism in postmenopausal women. In a parallel design, the diet of postmenopausal women was supplemented with either a placebo, soy (25 g soy flour), or flaxseed (25 g ground flaxseed) muffin for 16 wk. Blood and 24-h urine samples were collected at baseline and at the endpoint. Urine samples were analyzed for phytoestrogens, estrogen metabolites (2-hydroxyestrone, 16alpha-hydroxyestrone), and serum hormones (estradiol, estrone, estrone sulfate). Serum and urine samples were also analyzed for biochemical markers of bone metabolism. Urinary concentrations of 2-hydroxyestrone, but not of 16alpha-hydroxyestrone, increased significantly in the flaxseed group. In the flaxseed group, the ratio of 2-hydroxyestrone to 16alpha-hydroxyestrone was positively correlated with urinary lignan excretion. In the soy and placebo groups, no significant correlation was observed. No significant change in serum hormones or biochemical markers of bone metabolism was observed within or between the treatment groups. Supplementation with flaxseed modifies urinary estrogen metabolite excretion to a greater extent than does supplementation with an equal amount of soy. This modification by flaxseed is associated with an increase in urinary lignan excretion. Despite the shift in estrogen metabolism to favor the less biologically active estrogens, a negative effect on bone cell metabolism was not observed.

Hemodyalisis, kidney disease
Iran J Kidney Dis. 2016. Effects of Flaxseed Oil on Serum Lipids and Lipoproteins in Hemodialysis Patients: a Randomized Controlled Trial. Mirfatahi M. Daily consumption of 6 g of flaxseed oil reduces serum triglyceride concentration, which is a risk factor for cardiovascular disease in hemodialysis patients, whereas it has no effects on other lipid parameters, especially lipoprotein(a).

Mirfatahi M, Tabibi H. Effect of flaxseed oil on serum systematic and vascular inflammation markers and oxidative stress in hemodialysis patients: a randomized controlled trial. Int Urol. 2016.
Mirfatahi M, Tabibi H. Effects of flaxseed oil on serum lipid and lipoproteins in hemodialysis patient: a rondomized controlled trial. Iranian journal of kidney disease. 2016.
Hadi tabibi, Maryam Mirfatahi, Effect of flaxseed oil on blood hepcidin and hematologic factors in hemodilysis patients, 2016.

Hot flash symptoms
Pilot evaluation of flaxseed for the management of hot flashes.
J Soc Integr Oncol. 2007.
The objective of this study was to evaluate tolerability and the effect of 6 weeks of flaxseed therapy on hot flash scores in women not wishing to receive estrogen therapy. To be included in the study, women had to have at least 14 hot flashes per week. The women were asked to add 40 grams of crushed flaxseed  daily to their diet. There was a fifty percent reduction in hot flash symptoms in the women who added flaxseed to their diet. However, half of the women had side effects which included to mild or moderate abdominal distention. Three out of tem experienced mild diarrhea, one experienced excess gas.

Inflammation reduction
Systemic inflammation in morbidly obese subjects: response to oral supplementation with alpha-linolenic acid.
Obesity Surgury. 2007.
Morbidly obese patients frequently display asymptomatic chronic activation of acute phase response, with potentially adverse metabolic and cardiovascular consequences. Aiming to investigate the supplementation of flaxseed flour, a source of omega-3 fatty acids, a prospective randomized double-blind cross-over study was designed. Outpatient obese subjects were given flaxseed flour (Farinha de Linhaca Dourada LinoLive, Cisbra, Brazil) in the amount of 30 g/day (5 g of alpha-linolenic acid - omega-3) and an equal mass of placebo (manioc flour) were administered for 2 weeks each. Variables included general biochemical investigation, white blood cell count (WBC), C-reactive protein (CRP), serum amyloid A (SAA) and fibronectin. Various inflammatory markers were elevated in the studied population, although not necessarily exceeding the normal range; Significant reduction could be demonstrated; Some persistent effects of flaxseed supplement 2 weeks after discontinuation were observed.

Inflammation
Flaxseed ingestion reduces circulating concentrations of c-reactive-protein and tumor necrosis factor alpha.

Metabolic syndrome
J Nutr. 2010. Lifestyle counseling and supplementation with flaxseed or walnuts influence the management of metabolic syndrome. Flaxseed and walnut supplementation may ameliorate central obesity.

Multiple Sclerosis
Supplementation is associated with a lower multiple sclerosis relapse rate.

Prostate cancer
At the American Society of Clinical Oncology's annual meeting, researchers discussed a study: of about half the 161 prostate-cancer patients were asked to eat three rounded tablespoons of flaxseed per day for a few weeks. They then underwent surgery to have their tumors removed. On post-surgical examination, their cancer cells were dividing less rapidly, perhaps because they had less access to active forms of testosterone. Scientists don't know if healthy people who eat a lot of flaxseed would have a lower risk for prostate cancer.

J Med Food. 2014 Jan 24. Preventive Effects of Lignan Extract from Flax Hulls on Experimentally Induced Benign Prostate Hyperplasia.

Flaxseed may slow growth of prostate tumors. Including it as part of a low-fat diet may slow the growth of tumors in men with prostate cancer. According to a study published in the journal Urology, 25 men with prostate cancer supplemented with 3 tablespoons of ground flaxseed daily for an average of one month had a greater rate of prostate tumor cell death than men who did not follow this diet.
    Flaxseed contains a fiber-like compound, lignan, which is thought to bind to testosterone and possibly help remove it from the body. This could, in turn, help suppress the growth of prostate cancer cells. Testosterone stimulates prostate cancer growth. Several conventional therapies block androgens such as testosterone as a way to control the spread of cancer.

Fish oil versus flaxseed oil
Why not just take flaxseed oil since it has omega 3s?
   There are several omega 3 fatty acids. They are named ALA (alpha linolenic acid ), EPA (eicosapentanoic acid) and DHA (docosahexanoic acid). ALA is found in flaxseed oil whereas EPA and DHA are found in fish oils. ALA is able to convert into EPA and then into DHA, but this takes several enzymatic steps in the body. Although most young people are able to easily convert ALA into EPA and DHA, older people may not be able to do so as well. So, the bottom line, I prefer fish oils to flaxseed oil, although flaxseed oil is an excellent source of omega-3 fatty acids and, as the study below indicates, ALA from flax seed oil can be easily converted into EPA and DHA, at least by its incorporation into red blood cells. For those of you who don't want to take any fish products, DHA, extracted from algae, is sold by itself.

An increase in plasma n–3 fatty acid content, particularly eicosapentaenoic acid (20:5n–3; EPA) and docosahexaenoic acid (22:6n–3; DHA), is observed after consumption of fish oil–enriched supplements. Because {alpha}-linolenic acid (18:3n–3; ALA) is the direct precursor of EPA and DHA, ALA-enriched supplements such as flax may have a similar effect although it is not clear if older adults have the same ability to make these metabolic conversions.

Biological activity of flaxseed oil as the source of omega-3 alpha-linolenic acid
Biomed Khim. 2004.
ALA is not equivalent in its biological effects to the long-chain omega-3 fatty acids found in marine fish oils. However, ALA is metabolized to eicosapentaenoic acid, which may replace arachidonic acid in membrane phospholipides. Ingestion of flaxseed oil may alter the generation of eicosanoids, procoagulant activity and other membrane-dependent responses and exert antiallergic, antiatherosclerotic, antiarrhythmic effects. Beneficial effects of flaxseed oil have been shown in prevention and management of cardiovascular disease.

It was suggested to supplement the Eyesight Rx with fish oil capsules. Can I substitute the flaxseed oil capsules instead?
    Flaxseed oil will not work as well for vision as would fish oils, but it could still be helpful for visual acuity.

Flax seed oil side effects, safety, danger
Unless taken in large amounts, flax seed oil has few side effects. Nevertheless, it's best not to overuse flax seed oil, one reason it that it is rich in calories.