The disappearance of fruit and vegetables from our diet lowers men's testosterone levels
Since fruit and vegetables have gradually disappeared from the Western diet, men's testosterone levels may have fallen sharply. We, the ignorant compilers of this free web magazine, dare to proclaim this bold statement with confidence after reading a forgotten animal study from the nineties.
Study
Fruits and vegetables are the most important nutritional sources of potassium. In their animal study, Spanish scientists at the University of Murcia wanted to find out the hormonal effects of a low-potassium diet by feeding male CD1 mice with very little potassium.
Results
After the mice in the experimental group received the low-potassium feed for 6 days, the decrease in the level of potassium in their blood was significant, but not yet dramatic. Yet the testosterone levels of the animals had already plummeted.
The researchers gave the mice injections with LH and GnRH. These hormones boosted the testosterone level of the mice, but the effect of these hormones was stronger in mice that had received sufficient potassium. Potassium deficiency apparently makes the testes less responsive to LH.
The researchers looked in the pituitary gland at the amount of cells that produced LH. Those cells were larger - and contained more LH - if the animals had consumed enough potassium. Potassium deficiency apparently also disrupts the production of hormones in the brain that must determine how much testosterone the testes should produce.
Conclusion
"In conclusion, our results indicate that hypokalemia produces a clear decrease in LH secretion and testosterone synthesis and suggest that testicular factors different from steroidal androgens could exert an important role in modulating GnRH synthesis or release," the researchers write.
Although you cannot always extrapolate the results of animal studies to people, the Spanish study may well be relevant to people. Potassium intake in developed countries is relatively low. According to American scientists, the optimum intake of potassium is 4700 milligrams per day. An epidemiological study from 2012 showed that only 2 percent of American adults actually consume this amount. [Am J Clin Nutr. 2012;96(3):647-57.]
Good sources of potassium are beetroot, soy, potatoes, sweet potatoes, avocado, salmon and spinach.
Source: Endocrinology. 1996;137(9):3738-43.
Since fruit and vegetables have gradually disappeared from the Western diet, men's testosterone levels may have fallen sharply. We, the ignorant compilers of this free web magazine, dare to proclaim this bold statement with confidence after reading a forgotten animal study from the nineties.
Study
Fruits and vegetables are the most important nutritional sources of potassium. In their animal study, Spanish scientists at the University of Murcia wanted to find out the hormonal effects of a low-potassium diet by feeding male CD1 mice with very little potassium.
Results
After the mice in the experimental group received the low-potassium feed for 6 days, the decrease in the level of potassium in their blood was significant, but not yet dramatic. Yet the testosterone levels of the animals had already plummeted.
The researchers gave the mice injections with LH and GnRH. These hormones boosted the testosterone level of the mice, but the effect of these hormones was stronger in mice that had received sufficient potassium. Potassium deficiency apparently makes the testes less responsive to LH.
The researchers looked in the pituitary gland at the amount of cells that produced LH. Those cells were larger - and contained more LH - if the animals had consumed enough potassium. Potassium deficiency apparently also disrupts the production of hormones in the brain that must determine how much testosterone the testes should produce.
Conclusion
"In conclusion, our results indicate that hypokalemia produces a clear decrease in LH secretion and testosterone synthesis and suggest that testicular factors different from steroidal androgens could exert an important role in modulating GnRH synthesis or release," the researchers write.
Although you cannot always extrapolate the results of animal studies to people, the Spanish study may well be relevant to people. Potassium intake in developed countries is relatively low. According to American scientists, the optimum intake of potassium is 4700 milligrams per day. An epidemiological study from 2012 showed that only 2 percent of American adults actually consume this amount. [Am J Clin Nutr. 2012;96(3):647-57.]
Good sources of potassium are beetroot, soy, potatoes, sweet potatoes, avocado, salmon and spinach.
Source: Endocrinology. 1996;137(9):3738-43.
