Diet can have a strong influence on the synthesis, storage and metabolism of testosterone. Chemically testosterone is a steroid hormone derived from the classic and easily recognisable cyclopentanoperhydrophenanthrene ring, and in this regard is similar to other steroid hormones such as oestrogen, vitamin D and cholesterol. Testosterone has both androgenic and anabolic effects which refers to its masculinising and muscle building effects, respectively. In addition, testosterone is also partly responsible for a general feeling of well being and contributes significantly to producing sexual desire in men and women. In the former testosterone synthesis occurs primarily in the testes, while in the latter the ovaries and adrenal glands are the primary locations of synthesis. Because of its androgenic and anabolic effects, athletes have been interested in maximising testosterone production since the compound was first isolated in 1935, and then later synthesised by Butenandt and Hanisch, something that won them the nobel prize.
Optimising testosterone levels is therefore of interest, primarily athletes interested in physical performance. This is because the androgenic properties of testosterone can decrease recovery times and the anabolic effects can help build skeletal muscle. As with all steroid hormones, testosterone is lipid soluble and this allows it to pass through cell membranes and activate receptors on DNA directly (rather than needing to use membrane bound receptors and second messengers). However, because it is lipid soluble it does not dissolve in the aqueous plasma and so transport around the body is problematic. To get around this problem testosterone is transported bound to proteins that allow it to dissolve in the blood. Two proteins, albumin and sex hormone binding globulin (SHBG) are responsible for transporting around 98 % testosterone. However, this 98 % is not free to activate receptors and so only around 2 % of the testosterone in the blood can interact with DNA and have anabolic and androgenic effects.
One method of increasing the effects of testosterone is to knock some of it off the transport proteins to increase the amount of free testosterone. This free testosterone would then be able to interact with nuclear receptors and elicit cellular effects. A number of nutritional strategies are able to increase free testosterone, but one of the most well researched and least controversial is the mineral boron. Boron is a trace mineral required for mammalian growth and is also required by plants for the integrity of their cell walls. Animal studies using high intakes of boron have shown that as boron intake increases, plasma and tissue concentrations rise. In one 4 week study1, rats fed 2 mg of boron per day had significant increases in plasma levels of steroid hormones including testosterone. Humans too seem to react to high intake of dietary boron with elevated levels of free testosterone. In one study2, 11.6 mg of boron increase testosterone significantly after just 1 week, while estrogen (oestradiol) levels fell.
Dr Robert Barrington’s Nutritional Recommendation: The interesting thing about the boron studies to date is that they show positive effect in healthy human males. Many animal studies confirm the testosterone raising effects of boron. In addition, boron supplementation at high intakes appears to also favourably affect some marker of inflammation. In the human study cited above, acute administration of 11.6 mg of boron caused a significant increase in testosterone, while 10 gm per day for 1 week also caused significant increases in plasma testosterone. Boron appears to be completely safe at these doses.
RdB
