Yeah, I don't believe the Columbus story either. I'd never heard of it before this movie. Where would the story have even come from? The indigenous people didn't have a written language. It would have been pretty hard to transmit it orally, since they were basically exterminated in the next few centuries. Shenanigans.

As a neuroscientist, I call BS on the hypothalamus stuff too. There is a grain of truth here. The hypothalamus is involved in endocrine secretion, and that function can be altered by stress and emotional states. The idea that we can "decide" how we're going to feel is one that I wouldn't dismiss out of hand, but I don't think there's robust evidence that people can "switch off" negative emotions and "switch on" positive ones.

However, the movie goes way, way beyond that. I took this summary from a review:
[ QUOTE ]
Emotions cause the hypothalamus to create and send to the pituitary gland neuropeptides (short-chain amino acid sequences) to be delivered to every cell in the body where they create profound chemical changes in the cell after docking with receptors on the cell wall. As with all chemical addictions, we become increasingly immune and need more to satisfy out craving as time passes. When the cell divides, the resulting cells have more receptors for that particular peptide and fewer receptors for vitamins, minerals, proteins and waste elimination. This inability to absorb nutrients and eliminate waste causes aging on the cellular level.

[/ QUOTE ]
There are three major inaccuracies.
1) Exposing receptors to a high level of any ligand (the stuff that binds to the receptor) causes a reduction in the number of receptors, not an increase. In fact, this reduction is the physical basis for tolerance of drugs of abuse. If you use heroin, your opioid receptors will begin to disappear, making you less sensitive the longer you use it.

2) Even if the first part were true, the production of hormone receptors is a very small portion of most cells' overall energy budget. Doubling the number of receptors wouldn't have much impact on the cells' ability to support itself.

3) No one really knows what causes "cellular" aging. Aging may be the result of an accumulation of small injuries that never heal 100%. It may be caused by shortening telomeres as cells divide again and again. There's NO evidence it's caused by cells having too many receptors.