PhD student Max Lambert (to the left) received huge attention at a congress in Portugal when he was invited to present the Danish studies on red clover extract (photo: Helene Bagger).

An untraditional collaboration between a farmer, a researcher and a young candidate in molecular nutrition and food technology documents that red clover extract can relieve symptoms of menopause and possibly also regenerate bone tissue in patients with osteoporosis.

Cows and sheep love the Danish traditional and juicy red clover growing in pastures and along roads. Since the 17th century red clover has been grown to feed cattle. Now it has been shown that the plant can benefit humans as well.

Research at Aarhus University Hospital and Aarhus University have documented that extract from red clover is effective to relieve hot flushes and other symptoms related to women during their menopause. And the remedy has no side effects contrary to treatment with oestrogen which increases the risk of developing especially breast and ovarian cancer and at times flu-like symptoms.
The new research results have even shown that a particularly potent extract of red clover may prevent the loss of bone tissue in the group of post menopausal women above 50 years at risk of developing osteoporosis. The researchers behind the first study have started collecting the results to be used in a new study with a larger number of participants with early stages of osteoporosis.

Knowledge of the farmer

It is the first time researchers have studied the medical effects of red clover in a clinical and physiological study. The plant contains oestrogen-like compounds – isolfavones – and has been a common dietary supplement for years. In the farming industry they know of the link between red clover and hormones. Cows and sheep are kept away from fields with clover when the plan is to breed; the vast quantities of clover they eat interferes with the process. However, there has been no scientific documentation for the medical qualities of clover. A Danish farmer and producer of red clover, Michael Mohr Jensen, contacted Per Bendix Jeppesen, researcher and PhD at Department of Endocrinology and Internal Medicine at Aarhus University Hospital. Per Bendix Jeppesen works at the diabetes laboratory and is known for his research in plants containing sugar-like substances. Michael Mohr Jensen encouraged the researchers to test the effect of red clover as a substitute for the loss of oestrogen after menopause.

– We were rather sceptical in the beginning to say the least. But then we studied the literature and discovered several exciting aspects. We were interested in the known physiological effects substances in red clover. Additionally, some smaller observational studies indicated that phytoestrogens could relieve some of the symptoms in menopause, says Per Bendix Jeppesen.

He together with PhD student and master of science Max Lambert, recruited 60 women above 40 years of age to participate in a 3-month trial. These women all had severe symptoms related to menopause.

Measuring sweat during the night

Half of the women drank 75 ml red clover extract twice a day and the other half received a placebo drink without red clover but with the same characteristic taste.
During the trial a number of markers were measured in the blood of participants and they had a bone density scan of the spine and hip.
Frequent spontaneous hot flushes is a typical symptom of menopause. Participants were equipped with a wrist watch-like device registering the amount of sweat during 24 hours. This is the first time this device has been used for measuring menopausal symptoms in the world.
The special thing about the red clover extract is that, contrary to usual dietary supplements with red clover, the extract is absorbed very easily and fast in the intestinal system. The extract is developed with this strength by coincidence. Michael Mohr Jensen has used a new technique to add lactic acid bacteria to the red clover , using these biological agents to increase shelf-life. This also increases the absorption of isoflavones and thus enhances the potency of the red clover as herbal medicine.

– There was clearly a positive effect among the participants receiving red clover. In some, the amount of sweat was reduced by up to 80%; in others the reduction was only 20%. On average, number of hot flushes was reduced by 32%. The different results are e.g. caused by differences in how the extract is absorbed and metabolised in the body, says Per Bendix Jeppesen.

Restoring bone mass

It was a surprise to the researchers that the women who had received the red clover extract had maintained their bone mass; this also applied to participants with the initial stages of osteoporosis (osteopenia).

- If we can stop the loss of bone mass by intervening early and offer preventive treatment with red clover extract, it would be great, says Per Bendix Jeppesen. The two researchers think that the plant may be able to restore lost bone mass. PhD student Max Lambert who has a master degree in molecular nutrition and food technology explains that experiments with rats have shown that large amounts of derived isoflavones are found in red clover and are able to slow down the destruction of bone mass. So far, their own studies indicate the same effect in humans.

– There are two different processes in the cells which are affected by the added types of oestrogen. Traditional oestrogen treatment contributes to slow down the loss of bone mass. At the same time it unfortunately causes an overstimulation of the alpha receptors oestrogen is attached to; this means an increased risk of breast and ovarian cancer. The substances in red clover have a strong attachment to beta receptors stimulating development of i.a. bone mass but they do not overstimulate cells in other organs, he says.
The results of the new research project are expected to be available in spring 2015; Moreover, the researchers hope they will be able to test other types than fluid red clover extract – preferably in the form of tablets. The only side effect of the extract is the rather poor taste, they admit.