viernes, septiembre 23, 2005

Polemico: afirma que el stress no incrementa la necesidad de vitaminas

drmirkin.com:

September 18, 2005
Stress Does Not Increase Need for Vitamins

Several years ago a major drug company claimed that its vitamin pills helped to relieve stress from the "complications of everyday life" and gave their products names such as "StressTabs." The New York Attorney General forced them to stop their deceptive advertising, but many people still remember and believe this claim. There is no evidence that stress increases your needs for vitamins or that taking vitamins will help you handle stress. When you eat vitamins in pills or in your food, they go into your bloodstream and then into cells. They function by combining with other chemicals in cells called apoenzymes, to form complete enzymes that cause reactions to proceed in your body. All chemical reactions in your body require enzymes to make them go, and that is why vitamins are essential. For example, all of the B vitamins form enzymes that convert food to energy. But since enzymes only start chemical reactions and are not used up by them, they can be used over and over again and only minuscule amounts are needed from your diet.

In the 1930's, Hans Selye of McGill University in Montreal reported that the adrenal glands contain the highest concentration in the body of vitamin C. The adrenal glands make cortisol from vitamin C. When a person is under stress, the adrenal glands make tremendous amounts of cortisol and the concentration of vitamin C in them drops. However, scientists have known for more than forty years that the levels of vitamin C in the adrenal glands are still high enough to continue to produce cortisol and that giving extra vitamin C will not increase production of cortisol. So the myth that vitamins treat stress is based on a misinterpretation of one study on one vitamin, and that research did not show that taking extra vitamins prevents stress."

Several years ago a major drug company claimed that its vitamin pills helped to relieve stress from the 'complications of everyday life' and gave their products names such as 'StressTabs.' The New York Attorney General forced them to stop their deceptive advertising, but many people still remember and believe this claim. There is no evidence that stress increases your needs for vitamins or that taking vitamins will help you handle stress. When you eat vitamins in pills or in your food, they go into your bloodstream and then into cells. They function by combining with other chemicals in cells called apoenzymes, to form complete enzymes that cause reactions to proceed in your body. All chemical reactions in your body require enzymes to make them go, and that is why vitamins are essential. For example, all of the B vitamins form enzymes that convert food to energy. But since enzymes only start chemical reactions and are not used up by them, they can be used over and over again and only minuscule amounts are needed from your diet.

In the 1930's, Hans Selye of McGill University in Montreal reported that the adrenal glands contain the highest concentration in the body of vitamin C. The adrenal glands make cortisol from vitamin C. When a person is under stress, the adrenal glands make tremendous amounts of cortisol and the concentration of vitamin C in them drops. However, scientists have known for more than forty years that the levels of vitamin C in the adrenal glands are still high enough to continue to produce cortisol and that giving extra vitamin C will not increase production of cortisol. So the myth that vitamins treat stress is based on a misinterpretation of one study on one vitamin, and that research did not show that taking extra vitamins prevents stress."

Articulo en SciAm Mind sobre los nootropicos y sobre la conciencia

smart drugs, consciousness

SciAm Mind: 'Smart drugs' and consciousness:
The new edition of [Scientific American Mind](http://www.sciammind.com/) has hit the shelves and two articles are freely available online: one on '[smart drugs](http://www.sciammind.com/article.cfm?articleID=0000E503-E27C-1329-A27C83414B7F0000)' and the other on the problem of [consciousness](http://www.sciammind.com/article.cfm?articleID=00019F6C-E9EC-1329-A41C83414B7F0000).

The article on 'smart drugs' or 'cognitive enhancers' is by neuroscientist [Michael Gazzaniga](http://en.wikipedia.org/wiki/Michael_Gazzaniga) - most renowned for his work on [split-brain](http://en.wikipedia.org/wiki/Split-brain) patients.

Gazzaniga examines the ethical implications of having a society cranked-up on pharmaceutical brain enhancers, and looks at the science behind some of the most recent developments in the field.

He makes one particularly interesting point in relation to the relatively developed field of memory enhancing drugs, which have the potential to make the important process of forgetting more difficult:
For a society that spends significant time and money trying to be liberated from past experiences and memories, the arrival of new memory enhancers has a certain irony. Why do people drink, smoke marijuana and engage in other activities that cause them to take leave of their senses? Why are psychiatry offices full of patients with unhappy memories they would like to lose? And why do victims of horrendous emotional events such as trauma, abuse or stressful relationships suffer from their vivid recollections? A pill that enhances memory may lead to a whole new set of disorders.

The article on consciousness is by [Christof Koch](http://en.wikipedia.org/wiki/Christof_Koch), who highlights recent research which has looked for the '[neural correlates](http://en.wikipedia.org/wiki/Neural_correlate_of_consciousness) of consciousness' - i.e. which parts of the brain are active when conscious experience is known to occur.

This is a common but controversial approach to understanding consciousness, and one that has been championed by Koch in his own work.

Additional articles that appear in the print edition only include a discussion of the developing mind of infants and what it could tell us about the differences between men and women, the psychology of child-parent interaction and how it is understood (or misunderstood) by the courts, plus an exploration of synaesthesia.


[Link](http://www.sciammind.com/) to Scientific American Mind.

—[Vaughan](http://tinyurl.com/6udmu).

En http://www.mindhacks.com/blog/2005/09/sciam_mind_smart_d.html