Studies have found that flaxseeds have a number of health benefits including the ability to lower blood pressure, improve glycemic control, reduce breast cancer risk and to support a healthy bodyweight.
Flaxseed’s are one of my favorite plant-based “superfoods”, very versatile and great for supporting cardiovascular health due to being an excellent source of Omega-3 fatty acids(α-Linolenic acid), lignans and fiber.
Components of flax may possess phytogestrogenic, anti-inflammatory, and hormone modulating effects, respectively.
Flaxseeds have approximately 100 times more lignans than other foods. Lignans are phyto-estrogens that relieve the symptoms of menopause and can balance hormones in the body such as estrogen, by binding to receptors and producing a weak mimicking estrogenic effect, preventing stronger estrogens from being absorbed.
Flaxseed is also a good source of other nutrients including magnesium, phosphorus, manganese, vitamin B1, selenium, and zinc.
Let’s take a look at the current scientific research on the evidence-based health benefits of flaxseed.
Flaxseed Significantly Improves Glycemic Control
A systematic review and meta-analysis of 25 randomized controlled trials published 2018 assessed the effects of flaxseed consumption on glycemic control.
Meta-analysis suggested a significant association between flaxseed supplementation and a reduction in blood glucose.
No significant effect on HbA1c was found.
In subgroup analysis, a significant reduction in blood glucose, insulin, and HOMA-IR and a significant increase in QUIKI were found only in studies using whole flaxseed but not flaxseed oil and lignan extract.
Furthermore, a significant reduction was observed in insulin levels and insulin sensitivity indexes only in the subset of trials lasting ≥12 weeks.
The study concluded:
Whole flaxseed, but not flaxseed oil and lignan extract, has significant effects on improving glycemic control. 
Flaxseed Lowers Blood Pressure
A systematic review and meta-analysis of 15 randomized controlled trials published 2016 assessed the impact of the effects of flaxseed supplements on blood pressure.
The study concluded:
This meta-analysis of RCTs showed significant reductions in both SBP and DBP following supplementation with various flaxseed products. 
Flaxseed & Breast Cancer
Phyto-estrogens such as lignans actually have a protective role to play in not only reducing breast cancer risk in the first place, but also helping to balance hormones in the body.
As discussed previously phyto-estrogens are weak mimicking estrogenic, polyphenolic compounds such as lignans and isoflavones, which bind to receptors, preventing stronger estrogens from being uptaken.
Studies have found phyto-estrogens to provide a number of health benefits including the ability to reduce menopause symptoms such as hot flushes, improving bone density, plus lowered risk of developing cardiovascular disease, obesity, type 2 diabetes and various cancers.
Flaxseed has been a vastly studied ‘functional food” due to it’s potential relationship it may have with breast cancer.
One of the main components of flaxseed is the lignans, of which 95% are made of the predominant secoisolariciresinol diglucoside (SDG). SDG is converted into enterolactone and enterodiol, both with antiestrogen activity and structurally similar to estrogen; they can bind to cell receptors, decreasing cell growth.
Some studies have shown that the intake of omega-3 fatty acids is related to the reduction of breast cancer risk. In animal studies, α-linolenic acids have been shown to be able to suppress growth, size, and proliferation of cancer cells and also to promote breast cancer cell death.
Experimental studies conducted showed that flaxseed increases or maintains tamoxifen’s efficacy on the decrease of tumor growth on cell proliferation and on the increase of apoptosis.
Additionally, some clinical trials showed that flaxseed can have an important role in decreasing breast cancer risk, mainly in postmenopausal women. 
A systematic review published 2014 concluded:
Current evidence suggests that flax may be associated with decreased risk of breast cancer. Flax demonstrates antiproliferative effects in breast tissue of women at risk of breast cancer and may protect against primary breast cancer. Mortality risk may also be reduced among those living with breast cancer. 
Flaxseed, Obesity & Weight Loss
There were significant reductions in both body weight and waist circumference following flaxseed supplementation.
The study concluded:
Whole flaxseed is a good choice for weight management particularly for weight reduction in overweight and obese participants. 
 Flaxseed supplementation on glucose control and insulin sensitivity: a systematic review and meta-analysis of 25 randomized, placebo-controlled trials.
 Effects of flaxseed supplements on blood pressure: A systematic review and meta-analysis of controlled clinical trial.
 The Effect of Flaxseed in Breast Cancer: A Literature Review
 Flax and Breast Cancer: A Systematic Review.
 The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta‐analysis of 45 randomized placebo‐controlled trials
The information in this article has not been evaluated by the FDA and should not be used to diagnose, cure or treat any disease, implied or otherwise.