The warm, earthy and subtly nutty flavor of flaxseeds combined with an abundance of omega-3 fatty acids makes them an increasingly popular addition to the diets of many a health conscious consumer. Whole and ground flaxseeds, as well as flaxseed oil, are available throughout the year.

Flaxseeds are slightly larger than sesame seeds and have a hard shell that is smooth and shiny. Their color ranges from deep amber to reddish brown depending upon whether the flax is of the golden or brown variety. While whole flaxseeds feature a soft crunch, the nutrients in ground seeds are more easily absorbed. 

Health Benefits

Flaxseeds are rich in alpha linolenic acid (ALA), an omega-3 fat that is a precursor to the form of omega-3 found in fish oils called eicosapentaenoic acid or EPA. Since the fats are found in their isolated form in flaxseed oil, it is a more concentrated source of ALA than the seeds themselves (although it doesn't have the other nutrients that the seeds do). ALA, in addition to providing several beneficial effects of its own, can be converted in the body to EPA, thus providing EPA's beneficial effects. For this conversion to readily take place, however, depends on the presence and activity of an enzyme called delta-6-destaurase, which, in some individuals, is less available or less active than in others. In addition, delta-6-desaturase function is inhibited in diabetes and by the consumption of saturated fat and alcohol. For these reasons, higher amounts of ALA-rich flaxseeds or its oil must be consumed to provide the same benefits as the omega-3 fats found in the oil of cold-water fish.

Yet research indicates that for those who do not eat fish or wish to take fish oil supplements, flaxseed oil does provide a good alternative. A study published in the Journal of Nutrition found that flaxseed oil capsules providing 3 grams of alpha-linolenic acid daily for 12 weeks-an amount that would be provided by 3 tablespoons of flaxseed oil a day-increased blood levels of EPA by 60% in a predominantly African-American population with chronic illness.

Anti-Inflammatory Benefits

Omega-3 fats are used by the body to produce Series 1 and 3 prostaglandins, which are anti-inflammatory hormone-like molecules, in contrast to the Series 2 prostaglandins, which are pro-inflammatory molecules produced from other fats, notably the omega-6 fats, which are found in high amounts in animal fats, margarine, and many vegetable oils including corn, safflower, sunflower, palm, and peanut oils. Omega-3 fats can help reduce the inflammation that is a significant factor in conditions such as asthma, osteoarthritis, rheumatoid arthritis, migraine headaches, and osteoporosis.

Omega-3-rich Flaxseeds Protect Bone Health

Alpha linolenic acid, the omega-3 fat found in flaxseed and walnuts, promotes bone health by helping to prevent excessive bone turnover-when consumption of foods rich in this omega-3 fat results in a lower ratio of omega-6 to omega-3 fats in the diet.(Griel AE, Kris-Etherton PM, et al. Nutrition Journal)

Other studies have shown that diets rich in the omega-3s from fish (DHA and EPA), which also naturally result in a lowered ratio of omega-6 to omega-3 fats, reduce bone loss. Researchers think this is most likely because omega-6 fats are converted into pro-inflammatory prostaglandins, while omega-3 fats are metabolized into anti-inflammatory prostaglandins. (Prostaglandins are hormone-like substances made in our bodies from fatty acids.)

In this study, 23 participants ate each of 3 diets for a 6-week period with a 3 week washout period in between diets. All 3 diets provided a similar amount of fat, but their ratio of omega-6 to omega-3 fats was quite different:

Diet 1 provided 34% total fat with omega-6 and omega-3 fats in amounts typically seen in the American diet: 9% polyunsaturated fats (PUFAs) of which 7.7% were omega-6 and only 0.8% omega-3 fats, resulting in a pro-inflammatory ratio of 9.6:1.

Diet 2, an omega-6-rich diet, provided 37% total fat containing 16% PUFAs of which 12% were omega-6 and 3.6% omega-3, a better but still pro-inflammatory ratio of 3.3:1.

Diet 3, which provided 38% in total fats, was an omega-3-rich diet, containing 17% PUFAs, of which 10.5% were omega-6 and 6.5% omega-3, resulting in an anti-inflammatory ratio of 1.6:1.

After each diet, subjects' blood levels of N-telopeptides, a marker of bone breakdown, were measured, and were found to be much lower following Diet 3, the omega-3-rich diet, than either of the other two.

The level of N-telopeptides seen in subjects' blood each diet also correlated with that of a marker of inflammation called tumor necrosis factor-alpha (TNF-alpha). Diets 1 and 2-the diets which had a significantly higher ratio of omega-6 to omega-3 fats-also had much higher levels of TNF-alpha than the Diet 3, which was high in omega-3 fats from walnuts and flaxseed. Practical Tip: Protect your bones' by making anti-inflammatory omega-3-rich flaxseed and walnuts, as well as cold water fish, frequent contributors to your healthy way of eating.

Protection Against Heart Disease, Cancer and Diabetes

Omega-3 fats are used to produce substances that reduce the formation of blood clots, which can reduce the risk of heart attack and stroke in patients with atherosclerosis or diabetic heart disease.

Omega-3 fats are also needed to produce flexible cell membranes. Cell membranes are the cell's gatekeepers, allowing in needed nutrients while promoting the elimination of wastes. While important for everyone, flexible cell membranes are critical for persons with diabetes since flexible cell membranes are much better able to respond to insulin and to absorb glucose than the stiff membranes that result when the diet is high in saturated and/or hydrogenated (trans-) fats. In the colon, omega-3 fats help protect colon cells from cancer-causing toxins and free radicals, leading to a reduced risk for colon cancer.

Flaxseeds Help Prevent and Control High Blood Pressure

Individuals whose diets provide greater amounts of omega-3 fatty polyunsaturated fatty acids-and flaxseed is an excellent source of these essential fats-have lower blood pressure than those who consume less, shows data gathered in the International Study of Macro- and Micro-nutrients and Blood Pressure (INTERMAP) study (Ueshima H, Stamler J, et al. Hypertension).

The INTERMAP is a study of lifestyle factors, including diet, and their effect on blood pressure in 4,680 men and women aged 40 to 59 living in Japan, China, the U.S. and the U.K. Blood pressure was measured and dietary recall questionnaires were completed by participants on four occasions. Dietary data was analyzed for levels of omega-3 fatty acids from food sources including fish, nuts, seeds and vegetable oils.

Average daily intake of omega-3 fatty acids was 2 grams. Participants with a high (o.67% kcal) omega-3 fatty acid percentage of their daily calorie intake had an average systolic and diastolic blood pressure reading that was 0.55/0.57 mm Hg less, respectively, than participants with lower intake. Previous research has found that a decrease of 2 mm Hg reduces the population-wide average stroke mortality rate by 6 percent and that of coronary heart disease by 4%.

Higher omega-3 fatty acid intake among the 2,238 subjects who were not using drugs, supplements, or a special diet for hypertension, heart disease, or diabetes was associated with a 1.01/0.98 mm Hg reduction in systolic and diastolic blood pressure, respectively.

For the 2,038 subjects in this group who did not have hypertension, greater intake was associated with a 0.91/0.92 mm Hg average systolic and diastolic reduction.

Lead author Hirotsugu Ueshima, MD of Shiga University of Medical Science in Japan, noted that the beneficial effect of omega-3 fats was even greater in people who had not yet developed high blood pressure.

The researchers also found that omega-3s from nuts, seeds, and vegetable oils-such as walnuts and flaxseed-had just as much impact on blood pressure as omega-3s from fish. "With blood pressure, every millimeter counts. The effect of each nutrient is apparently small but independent, so together they can add up to a substantial impact on blood pressure. If you can reduce blood pressure a few millimeters from eating less salt, losing a few pounds, avoiding heavy drinking, eating more vegetables, whole grains and fruits (for their fiber, minerals, vegetable protein and other nutrients) and getting more omega-3 fatty acids, then you've made a big difference," said Ueshima.

Flaxseed Provides Comparable Cholesterol-Lowering Benefits to Statin Drugs

In a study involving 40 patients with high cholesterol (greater than 240 mg/dL), daily consumption of 20 grams of ground flaxseed was compared to taking a statin drug. After 60 days, significant reductions were seen in total cholesterol, LDL cholesterol, triglycerides and the ratio of total to HDL cholesterol-in both groups. Those receiving flaxseed did just as well as those given statin drugs!

Body mass index, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, and the ratio of total cholesterol/HDL-cholesterol were measured at the beginning of the study and after 60 days.

In those eating flaxseed, significant reductions were seen in total cholesterol (-17.2%), LDL-cholesterol (-3.9%), triglycerides (-36.3%) and the ratio of total cholesterol/HDL-cholesterol (-33.5%) were observed in the diet+flax group, compared to baseline. Similar reductions were seen in those taking the statin. Benefits did not significantly differ between the two groups.

Flaxseed Oil Lowers Blood Pressure in Men with High Cholesterol

Greek researchers looked at the effect on systolic and diastolic blood pressure of a three-month trial during which 59 middle-aged men used either flaxseed or safflower oil in their daily diet.

Flaxseed oil is rich in the omega-3 fat, alpha-linolenic acid (ALA), which the body can metabolize into the cardioprotective long-chain omega-3 fatty acids, DHA and EPA, while safflower oil is a concentrated source of the omega-6 fat, linoleic acid (LA). The men received flaxseed oil supplying 8 grams of ALA daily or safflower oil providing 11 grams of LA per day.

At the conclusion of the 12-week study, both systolic and diastolic blood pressure was significantly lower in the men using the omega-3-rich flaxseed oil.

One possible explanation for this result is the anti-inflammatory effects of omega-3 fats. Both omega-6 and omega-3 fats areessential fatty acids: we need both types of fats to be healthy and must derive them from our food. Omega-6 fats, however, tend to promote excessive inflammation when not balanced by sufficient amounts of omega-3 fats in the diet.

Most nutrition experts believe that a health-promoting ratio of omega-6 to omega-3 fats is no higher than 4:1, and many believe the optimal ratio is 2:1. The typical American diet, however, delivers almost 10 times as much omega-6 as omega-3 fatty acids. Practical Tip: Numerous studies have shown heart-protective benefits from decreasing the ratio of omega-6 to omega-3 fats in the diet. To improve your omega 6:omega to omega-3 ratio increase your consumption of foods rich in omega-3s, such as flaxseed oil, canola oil, walnuts, and cold-water fish like wild salmon. And decrease your consumption of foods rich in omega-6 fats, such as safflower oil, corn oil, peanut oil, butter and the fats found in meats.

Rich in Beneficial Fiber

Flaxseeds' omega-3 fats are far from all this exceptional food has to offer. Flaxseed meal and flour provides a very good source of fiber that can lower cholesterol levels in people with atherosclerosis and diabetic heart disease, reduce the exposure of colon cells to cancer-causing chemicals, help relieve constipation and stabilize blood sugar levels in diabetic patients. Flaxseeds are also a good source of magnesium, which helps to reduce the severity of asthma by keeping airways relaxed and open, lowers high blood pressure and reduces the risk of heart attack and stroke in people with atherosclerosis and diabetic heart disease, prevents the blood vessel spasm that leads to migraine attacks, and generally promotes relaxation and restores normal sleep patterns.

A study published in the Archives of Internal Medicine confirms that eating high fiber foods, such as flaxseed, helps prevent heart disease. Almost 10,000 American adults participated in this study and were followed for 19 years. People eating the most fiber, 21 grams per day, had 12% less CHD and 11% less CVD compared to those eating the least, 5 grams daily. Those eating the most water-soluble dietary fiber fared even better with a 15% reduction in risk of CHD and a 10% risk reduction in CVD.

Flaxseed Puts the Brakes on Prostate Cancer Growth

Flaxseed, a rich source of omega-3 fatty acids and lignans, put the brakes on prostate tumor growth in men who were given 30 grams of flaxseed daily for a month before surgery to treat their prostate cancer. The 40 men taking flaxseed, either alone or along with a low-fat diet, were compared to 40 men only following a low-fat diet, and 40 men in a control group who did not alter or supplement their usual diet. Men who took flaxseed, as well as those who took flaxseed combined with a low-fat diet did the best.

Lead author, Duke University researcher Wendy Demark-Wahnefried, believes the omega-3s in flaxseed alter how cancer cells lump together or cling to other cells, while flaxseed's anti-angiogenic lignans choke off the tumor's blood supply, thus helping to halt the cellular activity that leads to cancer growth.Journal of Clinical Oncology, 2007 ASCO Annual Meeting, Abstract 1510.

Practical Tip: Study participants took the flaxseed in a ground form to make it more digestible, and mixed it in drinks or sprinkled it on food such as yogurt, cereal or salads.

Special Protection for Women's Health

Flaxseed meal and flour have been studied quite a bit lately for their beneficial protective effects on women's health. Flaxseed is particularly rich in lignans, special compounds also found in other seeds, grains, and legumes that are converted by beneficial gut flora into two hormone-like substances called enterolactone andenterodiol. These hormone-like agents demonstrate a number of protective effects against breast cancer and are believed to be one reason a vegetarian diet is associated with a lower risk for breast cancer. Studies show that women with breast cancer and women who are omnivores typically excrete much lower levels of lignans in their urine than vegetarian women without breast cancer. In animal studies conducted to evaluate lignans' beneficial effect, supplementing a high-fat diet with flaxseed flour reduced early markers for mammary (breast) cancer in laboratory animals by more than 55%.

In a study published in the American Journal of Clinical Nutrition, when postmenopausal women ate a daily muffin containing either 25 grams (a little less than 1 ounce) of soy protein, 25 grams of ground flaxseed, or a placebo muffin containing neither for 16 weeks, the estrogen metabolism of those eating flaxseed, but not soy or placebo, was altered in several important protective ways:

• Levels of 2-hydroxyestrone, a less biologically active estrogen metabolite thought to be protective against breast cancer, increased significantly.

• The ratio of 2-hydroxyestrone (the protective estrogen metabolite) to 16alpha-hydroxyestrone (an estrogen metabolite thought to promote cancer) increased.

• Blood levels of the estrogen fractions (estradiol, estrone, and estrone sulfate) did not change significantly-which is important since estradiol is involved in maintaining bone mass.

So what does this mean in plain English? Eating about an ounce of ground flaxseed each day will affect the way estrogen is handled in postmenopausal women in such a way that offers protection against breast cancer but will not interfere with estrogen's role in normal bone maintenance.

In addition to lessening a woman's risk of developing cancer, the lignans abundant in flaxseed can promote normal ovulation and extend the second, progesterone-dominant half of the cycle. The benefits of these effects are manifold. For women trying to become pregnant, consistent ovulation significantly improves their chances of conception. For women between the ages of 35 and 55 who are experiencing peri-menopausal symptoms such as irregular menstrual cycles, breast cysts, headaches, sleep difficulties, fluid retention, anxiety, irritability, mood swings, weight gain, lowered sex drive, brain fog, fibroid tumors, and heavy bleeding, a probable cause of all these problems is estrogen dominance. Typically, during the 10 years preceding the cessation of periods at midlife, estrogen levels fluctuate while progesterone levels steadily decline. Flaxseed, by promoting normal ovulation and lengthening the second half of the menstrual cycle, in which progesterone is the dominant hormone, helps restore hormonal balance.

Preliminary research also suggests that flaxseeds may serve a role in protecting post-menopausal woman from cardiovascular disease. In a recent double-blind randomized study, flaxseeds reduced total cholesterol levels in the blood of postmenopausal women who were not on hormone replacement therapy by an average of 6%.

Lastly, lignan-rich fiber has also been shown to decrease insulin resistance, which, in turn, reduces bio-available estrogen, which also lessens breast cancer risk. And, as insulin resistance is an early warning sign for type 2 diabetes, flaxseed may also provide protection against this disease.

Flaxseed Reduces Hot Flashes Almost 60%

Researchers recruited 29 postmenopausal women who had suffered from at least 14 hot flushes each week for at least one month, but would not take estrogen because of a perceived increased risk of breast cancer. After taking 40 grams (1.4 ounces) of crushed flaxseed each day for six weeks, the frequency of hot flashes decreased 50%, and the overall hot flash score decreased an average 57% for the 21 women who completed the trial.