The anti-oestrogenic effect of wheat bran

Natural bodybuilders or health conscious women wanting to reduce their estradiol levels should add wheat bran to their diet. Twenty years ago biologists at TNO in the Netherlands did an animal study and discovered that estradiol is eliminated faster from the body the more wheat fibre you ingest.

A high estradiol level makes weight loss more difficult, makes the contours of your physique less sharp and in men can cause fat deposits in places you’d rather not have them, such as the chest area. Moreover, this same estradiol can convert into compounds that damage cell DNA and thus increase the chance of developing cancer.

Research done in the 1970s and 80s showed that sooner or later we lose half of all the estradiol molecules in our body via the intestines. The liver dumps the molecules via the bile into the gut contents. About eighty percent of that estradiol is then reabsorbed by the body.

You may be able to reduce the eighty percent to, say, seventy or sixty percent by getting the digested food to pass more quickly through the intestines, reasoned the TNO researchers. It may be possible to do this by increasing the amount of fibre in the diet. Fibre absorbs liquid and swells up, increasing the volume of the gut content and causing the intestines to work faster. On top of that, fibres – some work better than others here – can bind estradiol to themselves, thus making the hormone unavailable to the body.

The researchers tested their theory on male rats. They gave one group feed that contained no fibre [NF], another group feed with a low amount of fibre [LF] and a third group food with a high amount of fibre [HF]. For the high-fibre feed the researchers used wheat bran.

The addition of fibre to the diet led to a considerable increase in the amount of faeces produced per day, as the second figure below shows.

On the second day of the experiment the researchers injected radioactive estradiol into the rats. They then measured the amount of time it took for all the radioactive estradiol to find its way to the urine and faeces. This happened faster in the HF rats, as the figures on the left below shows.

After three weeks the researchers injected the rats again with radioactive estradiol. After this amount of time the gut has got used to a high-fibre diet, so the anti-oestrogenic effect of wheat bran may have disappeared as the result of an adjustment mechanism. But this was not the case, as the figures above right show.

“Once the microflora is adapted to the test diets the wheat bran diet still results in an accelerated fecal excretion of labeled compounds”, the biologists conclude. “This effect of dietary fiber might result in a lowered estrogen exposition to estrogen-sensitive tissue.”

More about this soon.