No.

Mindfulness meditation has a measurable and significant effect not only on stress, emotional regulation, recurrent thoughts/rumination, attention, and decision-making, but also a physical effect in the brain in the form of a reduction of amygdala size, and an increase in the activity (and size) of the prefrontal and anterior cingulate cortices.

`Internally', it changes the meditator's subjective sense of self and of how he experiences the world.

I dislike the way scientists and "objective thinkers" (for want of a better phrase) usually dismiss the placebo effect as something to be ignored.

If the placebo effect can be demonstrated to having positive effects in pain killing, and healing, it should be studied with enthusiasm.

We all know how stress can have negative effects on health. Why should the placebo effect and "positive thinking" not be able to have positive effects on health?

There are many different kinds of meditation, but some forms of calm meditation have been observed to produce numerous benefits beyond placebo effects, including lowering cortisol levels.

http://www.sciencedaily.com/releases/2010/08/100816155000.ht...

Is day to day life experience capable of causing change in the neural anatomy ? We know the answer is yes because people who go through intense trauma end up with brains that function differently in measurable ways, and that is well studied. Meditation is a similar thing except that where trauma causes brain damage meditation causes brain healing. Meditation is about learning to control and direct your faculty of attention in order to upgrade your brain's "wetware".

You're learning to choose a new primary neural pathway that tends to route around the fight/flight parts of the brain and route into lesser understood parts of the brain. The end effect is a calmer, happier, less worried you, but it takes.. well... practice :)

It may have no effect for some people. I practiced samatha/vipassana for over a decade at a Tibetan Buddhist center. This included daily sessions, one and two week solitary retreats, week-end and month-long group retreats. I met wonderful people but I experienced no change in attentiveness, clarity, calmness, or acceptance of my shortcomings. Meditation instructors said, "Just keep practicing." I did, but eventually lost interest and left the community years ago. My level of attentiveness does not seem to have decreased since. YMMV.

There are a lot of before/after studies of meditation. This book covers a lot of them from a pro-meditation point of view and includes brain scans comparing monks to people beginning meditation to people who have practiced meditation for a few weeks to a few months: http://www.amazon.com/Pictures-Mind-Neuroscience-Tells-Scien...

Yes. But something being a placebo effect doesn't mean it isn't also a 'real' physiological change.