Lignans are plant compounds called phytoestrogens, meaning they can gently interact with estrogen in the body. 

Their effects may vary depending on a woman’s hormone levels. In women with normal estrogen levels, lignans may help balance excess estrogen activity, while in women going through menopause, the hormonal balancing impact of phytoestrogens have been shown in various studies to help with menopause symptoms such as hot flashes and vaginal dryness. (101) (102)

In one study, Japanese women have historically shown low incidence of menopause symptoms compared to Canadian women. (67)  This is presumed to be due to the Japanese diet being high in phytoestrogens through soybean consumption.  In a collaborative studies phytoestrogens soy and flaxseed both had strong positive effects on hot flashes and vaginal dryness. (68)

In a study specifically done using a norwegian spruce extract , researchers found that supplementation led to a 50% decrease in hot flashes (9), while another study showed the hormonal balancing effects of HMR supplementation. (40)

Research has shown that populations with diets rich in phytoestrogens, such as many Asian populations, tend to have lower rates of certain hormone-related cancers. (63) This has led scientists to study plant compounds like lignans for their potential health benefits. (14)

Lignans are converted in the gut into compounds called enterolignans, which may help support hormone balance and healthy estrogen activity. Studies have found that higher levels of enterolignans, especially ENL, are associated with lower breast cancer mortality and may help reduce the growth of hormone-sensitive cancer cells. (44)(95)

Researchers believe lignans may support breast health through several mechanisms, including antioxidant activity, hormone regulation, and supporting healthy estrogen metabolism.

Prostate health is an increasingly important concern for aging men, with prostate cancer being the second most common cancer among men worldwide. 

Lignan supplementation provides some evidence to be supportive for prostate health.

Similar to what is seen with breast cancer, incidence of prostate cancer is highest in North America and Europe, with Asian populations showing lower incidence of the disease. (63) (79) 

Studies suggest that phytoestrogens like lignans and isoflavonoids may help protect against the growth of prostate cancer cells. Research has shown that enterolactone (ENL), a mammalian lignan produced from plant lignans in the gut, has anti-proliferative effects on prostate cancer cells. (63)(70)(116)(25) 

Human studies have also shown promising results. A Scottish case-control study found that higher serum ENL levels were associated with a lower risk of prostate cancer, while a meta-analysis of 11 studies linked increased enterolactone concentrations with significantly reduced prostate cancer risk.(118)(61) (80)

In an in-vivo study using 7-hydroxymatairesinol (HMR) from Norway Spruce, researchers observed reduced tumour growth and increased tumour cell apoptosis in mice. Researchers have also explored ENL’s ability to inhibit 5α-reductase, the same enzyme targeted by finasteride, which may help reduce DHT levels linked to prostate cancer and benign prostate enlargement. (24)(63)(21)

In mouse liver studies, a high-fat diet suppressed important cellular cleanup and fat-regulating pathways, including the TFEB gene, leading to increased fat accumulation and severe liver steatosis (fatty liver disease). 

Researchers found that 7-HMR and TEP helped restore TFEB levels closer to those seen in mice on a low-fat diet, suggesting lignans may help support the body’s natural ability to break down and regulate liver fat. 

These protective effects against liver steatosis were also observed in-vitro using liver cell models. (30)