Monday, September 27, 2010

7. Sulfur and Alzheimer's

With an aging population, Alzheimer's disease is on the rise, and it has been argued that the rate of increase is disproportionately high compared to the increase in the raw number of elderly people [Waldman2009]. Because of a conviction that the amyloid beta plaque that is a signature of Alzheimer's is also the cause, the pharmaceutical industry has spent hundreds of millions, if not billions, of dollars pursuing drugs that reduce the amount of plaque accumulating in the brain. Thus far, drug trials have been so disappointing that many are beginning to believe that amyloid beta is not the cause after all. Recent drug trials have shown not only no improvement, but actually a further decline in cognitive function, compared to placebo ( New York Times Article). I have argued elsewhere that amyloid beta may actually be protective against Alzheimer's, and that problems with glucose metabolism are the true culprit in the disease.

Once I began to suspect sulfur deficiency as a major factor in Americans' health, I looked into the relationship between sulfur deficiency and Alzheimer's. Imagine my surprise when I came upon a web page posted by Ronald Roth, which shows a plot of the levels of various minerals in the cells of a typical Alzheimer's patient relative to the normal level. Remarkably, sulfur is almost non-existent in the Alzheimer's patient's profile.

To quote directly from that site: "While some drugs or antibiotics may slow, or if it should happen, halt the progression of Alzheimer's disease, sulfur supplementation has the potential of not only preventing, but actually reversing the condition, provided it has not progressed to a stage where much damage has been done to the brain."

"One major reason for the increase in Alzheimer's disease over the past years has been the bad reputation eggs have been getting in respect to being a high source of cholesterol, despite the fact of dietary intake of cholesterol having little impact on serum cholesterol - which is now also finally acknowledged by mainstream medicine. In the meantime, a large percentage of the population lost out on an excellent source of sulfur and a host of other essential nutrients by following the nutritional misinformation spread on eggs. Of course, onions and garlic are another rich source of sulfur, but volume-wise, they cannot duplicate the amounts obtained from regularly consuming eggs."

Why should sulfur deficiency be so important for the brain? I suspect that the answer lies in the mysterious molecule alpha-synuclein, which shows up alongside amyloid-beta in the plaque, and is also present in the Lewy Bodies that are a signature of Parkinson's disease [Olivares2009]. The alpha-synuclein molecule contains four methionine residues, and all four of the sulfur molecules in the methionine residues are converted to sulfoxides in the presence of oxidizing agents such as hydrogen peroxide [Glaser2005]. Just as in the muscle cells, insulin would cause the mitochondria of neurons to release hydrogen peroxide, which would then allow the alpha-synuclein to take up oxygen, in a way that is very reminiscent of what myoglobin can do in muscle cells. The lack of sufficient sulfur should directly impact the neuron's ability to safely carry oxygen, again paralleling the situation in muscle cells. This would mean that other proteins and fats in the neuron would suffer from oxidative damage, leading ultimately to the neuron's destruction.

In my essay on Alzheimer's, I argued that biologically pro-active restriction in glucose metabolism in the brain (a so-called type-III diabetes and a precursor to Alzheimer's disease) is triggered by a deficiency in cholesterol in the neuron cell membrane. Again, as in muscle cells, glucose entry depends upon cholesterol-rich lipid rafts, and, when the cell is deficient in cholesterol, the brain goes into a mode of metabolism that prefers other nutrients besides glucose.

I suspect that a deficiency in cholesterol would come about if there is insufficient cholesterol sulfate, because cholesterol sulfate likely plays an important role in seeding lipid rafts, while concurrently enriching the cell wall in cholesterol. The cell also develops an insensitivity to insulin, and, as a consequence, anaerobic metabolism becomes favored over aerobic metabolism, reducing the chances for alpha-synuclein to become oxidized. Oxidation actually protects alpha-synuclein from fibrillation, a necessary structural change for the accumulation of Lewy bodies in Parkinson's disease (and likely also Alzheimer's plaque) [Glaser2005]

1 comment:

Alzheimer Disease said...

Our dementia and memory clinic in Toronto provides the tools necessary to deal with the many phases of memory impairment, from prevention, enhancing quality of life and planning for the future. We believe in an individualized approach for all our patients, exploring the benefits of nutrition, exercise, cognitive training and medication when appropriate.

Alzheimer’s clinic