Richard G. Petty, MD

Alzheimer’s: “A Disease of Civilization?”

I have had the pleasure of receiving some excellent comments after the recent article about Alzheimer’s disease.

One suggestion was that Alzheimer’s is a modern illness caused by mercury in dental fillings. This has been a popular idea for several years, and I knew an holistic dentist in Philadelphia who told me about some people who seemed to be relieved of an array of symptoms after their mercury-containing fillings were removed.

Over the last few years I have spent a long time reading books on the topics and analyzing published studies in detail.

These are some of the books with which I started:

  1. Warren T. Beating Alzheimer’s: A Step Towards Unlocking the Mysteries of Brain Diseases. Garden City Park, New York: Avery Publishing Group Inc., 1991.
  2. Huggins HA. It’s All in Your Head: The Link Between Mercury Amalgams and Illness. Garden City Park, New York: Avery Publishing Group Inc., 1993.
  3. Walker M, Whitaker J. Elements of Danger: Protect Yourself Against the Hazards of Modern Dentistry. Charlottesville, Virginia: Hampton Roads Publishing Company Inc., 2000.
  4. Hardy JE. Mercury Free: The Wisdom Behind the Global Consumer Movement to Ban "Silver" Dental Fillings Glassboro, New Jersey: Gabriel Rose Press Inc., 1996.

One of the best resources that I’ve found for people interested in the potential problems that may be caused by dental amalgams is here.

Clearly there is a potential for harm. At one time I considered having my fillings removed, but in the end I didn’t.

Why did I make that decision?

After all, mercury is neurotoxic, which is one of the reasons for all the concern about thimerosal in vaccines, and its alleged link to autism. And I would prefer to avoid getting Alzheimer’s disease. I have no family history of it. In fact the opposite: my father was estimated to have an IQ in the 170-180 range when he was in his nineties. But it is still a concern.

While some people seem to have benefited form having their fillings removed, many have not. So there must be some other factor or factors, likely including a genetic predisposition. People have created genetically deformed animals with all the signs of Alzheimer’s disease, but without a molecule of mercury in sight.

It is constantly being said that Alzheimer’s disease is a modern illness, and that its appearance roughly coincided with the introduction of mercury fillings. But that’s not true. Alois Alzheimer did describe the classic pathological signs of the disease in 1906. It was only made possible by the development of a new silver staining method developed by Alzheimer’s colleague Franz Nissl. For the first 70 years after it was first described, Alzheimer’s disease was regarded as a “Pre-senile” dementia.

But dementia had been described at least two thousand years earlier by Lucretius.

Some of those early descriptions probably included a ragbag of different illnesses, but for at least 2,000 years, from Rome to China, there were clear descriptions of something that looks just like modern Alzheimer’s disease. There are descriptions by the great English physician Thomas Willis, and the term “demented” entered the English language in 1644. There was a famous description of Sir John Roberts of Bromley, who was described by his physician, William Salmon as “decayed in his intellectuals.” That was in 1694.

There are extensive descriptions of “senile dementia” from many of the famous names in the history of psychiatry, including Cullen, Pinel and Esquirol. So the idea that it is a modern illness is not correct. Has it been becoming more common? Possibly, but it is difficult to say, because in 1905 the average life expectancy in the United States was 47 years.

When I really started analyzing the research in detail, I was not impressed by the data linking mercury with Alzheimer’s disease and multiple sclerosis. There are definitely some reports (1.2.) of possible links between neurodegeneration and mercury, but the most recent epidemiological studies have failed to find a link. Indeed there has been a great deal of research indicating that – for most people – amalgams are safe. ( 1. 2. 3. 4.) although it is important that the research should continue. Last year the U.S. Food and Drug Administration (FDA) panel called for an additional review of scientific studies on the safety of dental amalgam fillings. Some of the responses are here.

My own take on this is as follows:

  1. The evidence for a causal link between mercury – primarily from fillings – and Alzheimer’s disease is thin.
  2. The quality of the evidence for many other conditions, such as multiple sclerosis is also not of good quality.
  3. There is still a great deal that we do not know about the medical consequences of mercury containing amalgams, particularly in children and pregnant women.
  4. I am going to continue to update this information as more data is published.

At the moment I still have my fillings.

But there is another reason: the few that I have were done in England, and for years now there have been restrictions on the use of mercury-containing amalgams.

Asthma, Air and Allergies

After a couple of weeks away I was distressed to see that I was going to be returning to a city which has just been rated as the most challenging place in America for people with asthma.

This is the list according to the Asthma and Allergy Foundation of America:

  1. Atlanta
  2. Philadelphia
  3. Raleigh, North Carolina
  4. Knoxville, Tennessee
  5. Harrisburg, Pennsylvania
  6. Grand Rapids, Michigan
  7. Milwaukee
  8. Greensboro, North Carolina
  9. Scranton, Pennsylvania
  10. Little Rock, Arkansas

I am pleased to say that I do not have asthma, though I have a strong family history of it. If you live in one of these cities, or any other with a high rate of pollution, there is nothing much to be done apart from:

Staying indoors when the weather is bad

Using an air purifier

Keep to a diet designed to reduce your risk of inflammation

Use homeopathy and tapping therapies to help when necessary.

And sadly, for some people, medicines are the only option. But I always try the other approaches as well.

Pesticides, Weight Gain and Insulin Resistance

On this blog and in Healing, Meaning and Purpose, I have talked about some of the less well recognized contributors to obesity, including:

  1. Stress
  2. Salt
  3. Viruses
  4. Pesticides
  5. Intestinal bacteria

There is some new evidence from Korea published in the journal Diabetes Care, supporting the possible contribution of pesticides to insulin resistance.

People with high levels of persistent organic pollutants (POPs) in their blood were more likely to develop insulin resistance, which may lead to type 2 diabetes. Insulin resistance may also lead to obesity, hypertension and an array of other diseases. It is well recognized that increasing amounts of intra-abdominal fat may increase insulin resistance. It is less well known that this obesity is part of a viscous circle, with insulin resistance being associated with elevated insulin levels that may cause fat to be laid down throughout the body. Once the fat is laid down in the abdomen, it can break down, releasing fatty acids and triglycerides that in turn affect the breakdown of insulin by the liver and the release of insulin by the pancreas.

Previous research by the same group found a link between POPs and type 2 diabetes. This study confirms that background exposure to some POPs, chemicals such as organochlorine pesticides and polychlorinated biphenyls (PCBs), is also associated with insulin resistance among people who do not yet have diabetes.

The researchers also found that the association between organochlorine pesticides and insulin resistance became stronger as people got fatter. However, among people who had very low concentrations of pesticides in their blood, the researchers found little association between waist size and insulin resistance.

Some studies have suggested an association between background exposure to POPs and a variety of adverse health effects in humans and wildlife. POPs can be particularly problematic because they persist for long periods of time in the environment, accumulate up the food chain, and can travel great distances through the air and water. Therefore, even people and animals that live nowhere near a place where POPs are being applied often show high levels of these chemicals in their bloodstream.

An international treaty banning a dozen of the world’s most dangerous POPs has helped reduce exposures, but many harmful chemicals remain in use and even those that have been banned may linger in our environment for years to come. For example, chlordane was banned two decades ago in the United States but continues to be present at high levels in our food supply.

The researchers concluded that some POPs "may be involved in the pathogenesis of insulin resistance." They advise urgent prospective studies among those who have background exposure to POPs, which mostly comes from eating fatty animal foods. Since obesity may increase the toxicity of POPs, controlling weight could also help to reduce the impacts of these molecules.

In separate research involving mice, Frederick vom Saal from the University of Missouri in Columbia, Missouri has studied the effects of a different class of endocrine-disrupting chemicals, including bisphenol-A (BPA). Not long ago, BPA made news in San Francisco, where there was a lot of controversy over an ordinance that seeks to ban its use in children’s products. vom Saal’s most recent work was presented at the 2007 Annual Meeting of the American Association for the Advancement of Science (AAAS). He found that endocrine-disrupting chemicals cause mice to be
born at very low birth weights and then very rapidly gain abnormally
large amounts of weight: they could more than double their body weight
in just seven days. Vom Saal followed the mice as they got older and
found that these mice were obese throughout their lives. He said
studies of low-birth-weight children have shown a similar
overcompensation after birth resulting in lifelong obesity.

(Regular readers might remember the concept of the thrifty phenotype, and see how this research ties in with that concept). More research must be done to determine which chemicals cause this metabolic effect. According to vom Saal, there are approximately 55,000 manmade chemicals in the world, and 1,000 of those might fall into the category of endocrine disrupting. These chemicals are found in common products, from plastic bottles and containers to pesticides and electronics.

These chemicals are so pervasive that it is difficult to avoid them, and there is scant evidence that "detoxification" helps clear them. That being said, and depsite the lack of evidence, we recommend certified organic produce and regular mild detoxification programs, together with nutritional support and  tapping therapies.

People Watching

For the eighth time in a week your humble reporter found himself at the Atlanta airport. Ahem, I should say, of course, the Hartsfield-Jackson Atlanta International Airport.

It’s a perfect place for people watching. New statistics out today have shown that in 2006 it held its position as the world’s busiest airport, followed by O’Hare in Chicago and London’s Heathrow.

I was chastened to realize that I have been in every one of the top ten airports in the last year or so. For people who like such things, here’s the list of the top ten busiest airports with the number of millions passengers who’ve been through each:

  1. Atlanta    84.8
  2. O’Hare    76.2
  3. Heathrow   67.5
  4. Tokyo’s Haneda    65.2
  5. Los Angeles International    61
  6. Dallas/Fort Worth    60
  7. Paris, Charles de Gaulle    56.8
  8. Frankfurt    52.8
  9. Beijing Capital International Airport    48.5
  10. Denver International    47.3

Spending a lot of time in airports can stress the physical, psychological and subtle systems of the body, as well as making it easy to lose touch with your spirituality.

I’m going to let you in on a secret: for over two decades I had learned and then taught methods for building resilience and bouncing back from adversity. But it wasn’t until I started flying a quarter of a million miles a year that I got the chance to test and refine the methods under the most extreme conditions. Engineers often talk about taking their constructions and “testing them to destruction.” I did the same thing with the methods I teach. If they couldn’t help people cope with flights, illness or job loss, then I discarded them and looked for something else. And if they didn’t also have another piece – a way to grow in response to adversity, they were out too.

The result has been a whole raft of techniques and methods that have been tried and tested again and again. Over the next year I shall be rolling out a great many of these techniques in a novel format.

Watch this space!

“Every adversity carries with it the seed of equal or greater benefit.”
–Napoleon Hill (American Founder of Personal Success Literature, 1883-1970)

“From the withered tree, a flower blooms.”
–Zen Buddhist Saying

“How you handle adversity in the workplace tends to have much more impact on your career than how you handle the good stuff. The people who know how to overcome adversity are the ones who rise to the top of the organization."
— Martin E. P. Seligman (American Psychologist, Professor at the University of Pennsylvania and Former President of the American Psychological Association, 1941-)

“Adversity is the diamond dust with which Heaven polishes its jewels.”
— Robert Leighton (Scottish Presbyterian Bishop and Classical Scholar, 1611-1684)

“Adversity has the effect of eliciting talents which in prosperous times would have lain dormant.”
–Horace (a.k.a. Quintus Horatius Flaccus, Roman Poet and Satirist, 65-8 B.C.E.)

“Adversity is not undesirable. Because, it is only when you are down and out in life that you can realize its true value.”
–Swami Ramdas (a.k.a. Papa Ramdas, Indian Spiritual Teacher, 1884-1963)

Deep Vein Thrombosis

I am sorry to hear that the United States Vice-President Dick Cheney has just developed a blood clot in his leg and is being treated with anticoagulants (blood-thinning medications) that he will need to be on for several months.

He experienced some discomfort in his lower left leg this morning, and the diagnosis of deep vein thrombosis was made.

Mr Cheney is now 66 years old and has a history of cardiac problems. He has suffered at least four  myocardial infarctions (heart attacks) and has a pacemaker.

He had quadruple bypass surgery in 1988 after his third heart attack.He also had an operation to remove blood clots around his knees in 2005.

Mr Cheney recently returned to Washington after long flights to Japan, Australia, Pakistan and Afghanistan.

As I discussed a few months ago deep vein thrombosis – often shortened to "DVT" – can be associated with long-distance flying because it leads to inactivity and dehydration. Not, as was formerly thought, low oxygen pressure.

Blood clots in the legs are not in themselves life-threatening but they can be dangerous if they become wedged in the lungs (pulmonary embolism) or other organs, which can in severe cases be fatal.

Although the venous and arterial sides of the circulation are often thought of as quite different, it is not that unusual for someone to have problems in both, either because of immobility, metabolic disturbances or low grade inflammation.

With Spring Break and early summer vacations coming up, please don’t forget to keep moving when you are on planes, limit the alcohol and coffee cnsumption, and have plenty of water to drink.

Bon voyage!

Air Pollution and Cardiovascular Disease

There a very important piece of research published in this week’s issue of the prestigious New England Journal of Medicine, indicating that air pollution increases the risk of cardiovascular disease, at least in women. The whole article is available for free download.

Researchers from the University of Washington studied 65,893 postmenopausal women without previous cardiovascular disease in 36 U.S. metropolitan areas from 1994 to 1998, with a median follow-up of 6 years. All the participants were aged 50 to 79 and part of the Women’s Health Initiative, a major US Government funded investigation into the causes of heart disease in women. A total of 1,816 women suffered one or more cardiovascular event.

The investigators were particularly interested in tiny airborne particles called particulates, which are less than 2.5 microns across, and can lodge in the lungs. Previous research had incriminated them in heart disease. These are the dense clouds that you see coming out of chimneys or exhaust pipes. They found that pollution levels varied between four to nearly 20 micrograms per cubic meter.

Each 10 microgram rise was matched by a 76% rise in the chances of dying from heart disease or stroke. For women living within, rather than between, cities, the risk more than doubled, increasing by 128%, with each step up in pollution levels.

It is not clear whether women are more susceptible to pollution than men. Women’s coronary arteries are smaller and this might render them more vulnerable.

These results suggest that the risk from air pollution is far greater than most doctors previously thought, though it is still not clear how these sooty particles lead to the development of heart disease.

I live just outside a city where we often have smog advisories for weeks at a time in the summer. This research adds to the growing evidence that air pollution should be taken seriously as a risk factor for cardiovascular disease.

That also means that when localized air pollution is particularly high, people with chronic lung disease or coronary heart disease should avoid staying outside.

This problem will likely get worse as the summers be progressively warmer.

Yet another reason for taking climate change seriously.

“For the first time in the history of the world, every human being is now subjected to contact with dangerous chemicals, from the moment of conception until death.”
–Rachel Carson (American Biologist and Writer, 1907-1964)

The Latest Report on Climate Change

As expected the Intergovernmental Panel on Climate Change (IPCC) concludes that there is more than a 90% chance that global warming has a human cause. The panel said that temperatures were probably going to increase by 1.8-4 degrees Celsius (3.2-7.2 degrees Fahrenheit) by the end of the century. It also projected that sea levels were most likely to rise by 28-43cm, and global warming was likely to influence the intensity of tropical storms.

The findings are the first of four IPCC reports to be published this year.

Also as expected, the attacks on the report began even before it was published. Some radio critics have committed a fundamental mistake of saying that people have been warning of this for years and nothing has happened. First, something has happened, and second, the report is careful to say that precise estimates are difficult. It is the direction of change which should be of greatest importance.

The Mail and Guardian Online is reporting that some scientists and economists have been offered $10 000 each by a lobby group funded by one of the world’s largest oil companies – ExxonMobil – to undermine the report.

There is also a very well reasoned article about the semantics of climate change. The precise language of science and the quite different way in which politicians and many marketing people use language. It is well worth reading.

My main concern remains the impact of climate change on health and well-being. And many parts of the world, from Florida to the Horn of Africa are already experiencing that.

Here Comes the Sun: To Screen or Not To Screen?

I have been worried to see some people – all, I think, without scientific training – proclaiming that there is no need to protect ourselves against the sun because there is no evidence that sulight causes any health problems.

Ultraviolet radiation (UVR) from the sun has been part of the environment since the first cells began to form. When we discuss the effects of UVR on human health and the environment, the range of UV wavelengths is often subdivided into:

  • UVA (400–315 nm), also called Long Wave or “blacklight”
  • UVB (315–280 nm), also called Medium Wave
  • UVC (< 280 nm) also called Short Wave or “germicidal”

The key questions are these:
Can sunlight cause health problems?
Do the benefits of sunlight outweigh their risks?”

UVB is required for the conversion of 7-deoxycholesterol to vitamin D, (the sunshine vitamin!) which is critically important in the maintenance of healthy bones, although there may also be another mechanism by which vitamin D is generated in the body. As we have seen research is making clear that vitamin D has other potential roles in the maintenance of human health. Low levels of vitamin D have been linked to:

  • Rickets
  • Osteomalacia
  • Osteoporosis
  • Maintaining the integrity of cell membranes
  • Type 2 diabetes mellitus
  • Schizophrenia
  • Multiple sclerosis
  • Pre-eclampsia (hypertension and accompanying problems during the late stages of pregnancy)
  • Some types of cancer
  • Fibromyalgia-like pains
  • Immune deficiency: Africa Americans do not generate enough of a protein needed to ward off tuberculosis. Why? Because the protein needs vitamin D to be activated, and dark skin is inefficient at absorbing and converting UVR. It may also be that we see epidemics of colds and flu in the winter because that is when we have low levels of vitamin D, which allows the viruses to overwhelm our immune defenses.

This does not necessarily mean that taking extra vitamin D will ward off all of these problems.

In the days before the Industrial Revolution, unless we lived in the frozen North, we had no trouble in getting the amount of vitamin D that we needed. In most of the United States, during the summer months, 10-15 minutes outdoors at midday will generate around 10,000 international units (IU’s) of vitamin D in an average fair-skinned person. This is far in excess of the government’s dietary recommendations of 200 IU’s/day in people up to age 50, 400 IU’s up to age 70 and 600 IU’s in people over 70. Not surprisingly many experts – me included – believe and have provided evidence that these daily requirements are much too low. (Have a look at the comments here.)

Of course many of us do not spend much time outside and don’t take in as much in the way of vitamin D containing foods – such as milk and salmon – as we should. I’ve seen evidence to suggest that we in Atlanta are probably at the Northernmost point in the United States were we could hope to get enough sunshine and therefore vitamin D from modest winter exposure to the sun.

Recent data has suggested that if you spend no time at all in the sun, then you may need as much as 4,000 IU’s of vitamin D/day, though that figure has not yet been widely accepted.

Exposure to UVR, whether of solar or artificial origin, also carries potential risks to human health. UVR is a known carcinogen and excessive exposure, at least to the solar radiation in sunlight, increases the risk of cancer of the lip, basal cell, and squamous cell carcinoma of the skin and melanoma, particularly in fair-skinned populations. There is also evidence that solar UVR increases risk of several diseases of the eye, including cortical cataract, some conjunctival neoplasms, and perhaps also melanoma of the eye.

We have good data for the existence of a threshold amount of UV-B exposure that may lead to the formation of cataracts. The amount needed to cause cataracts depends in part on the amount of pigment in the eye, so albino rats get cataracts with much lower exposures to UV-B.

So what to do?

Sunlight has a definite benefit in preventing or treating many clinical problems and it is no surprise that after 3000 millennia we are adapted to make use of the sun’s largesse. What is less easy to understand is why an excess of sunlight can cause so many problems, unless it is our hairlessness and environmental change that has lead to a loss of the ozone layer.

Some years ago it was suggested that sunscreens may themselves cause skin cancer, but the data has shown that to be false. Indeed modern sunscreens almost certainly reduce melanoma risk.
So how do we balance the positive and negative effects of sunlight? A recent review precisely reflects my own thinking:

  • We need some sunlight
  • Depending on where you live, you need only a few minutes each day
  • Sunscreens confer protection on the skin without blocking all the health benefits
  • If you have a medical reason for avoiding sunlight, then your health care provider should measure your vitamin D status.

The Red Tide

There is an important report about the impact of environmental change in this month’s issue of the journal Chest.

Red tide is a common name for a phenomenon known as an algal bloom,
a well known event in which marine algae accumulate rapidly in the
water column, or “bloom”. These algae, more correctly termed phytoplankton, are microscopic, single-celled, plant-like organisms that can form dense, visible patches near the water’s surface. We know that red tides have been occuring in the Gulf of Mexico for centuries, but they appear to be spreading and to be becoming more common and severe.

The main type of plankton is a species of dinoflagellate known as Karenia brevis, that is concentrated along shorelines and produce highly potent aerosolized toxins. The new research shows that Florida red tide toxins – called brevetoxins can impact respiratory function and increase respiratory symptoms in patients with asthma.

In otherwise healthy people inhaled aerosolized red tide toxins can lead to eye irritation, runny nose, postnasal drip, nonproductive cough, and wheezing. The symptoms usually subside after leaving beach areas. But things can be far more serious for people with asthma, who may experience respiratory problems and decreased lung function after just one hour of beach exposure to the toxins.

This was a fine piece of research funded by the National Institute of Environmental Health Sciences, and makes it clear that not only that asthma sufferers need to be aware of this potential source of trouble but that we all need to be alert to the possibility that human activities are increasing the red tide and with it, the risk of further health problems.

Parkinson's Disease and Cholesterol

Within the last week we have talked about the association between Helicobacter pylori and Parkinson’s disease and the way in which Parkinson’s disease may often get better if people are treated with a cocktail of antibiotics. We have also discussed the association between Parkinson’s disease, allergies and inflammation.

Now new research from the University of North Carolina at Chapel Hill has  found that people with low levels of LDL cholesterol are more likely to have Parkinson’s disease than people with high LDL levels. This is the form of cholesterol sometimes referred to as "bad cholesterol." This study followed the strange observation that people with Parkinson’s disease have a lower rates of heart attack and stroke than people who do not have the disease. It is also known that known that cigarette smoking, which increases a person’s risk for cardiovascular disease, is also associated with a decreased risk of Parkinson’s disease. 

Few scientific stories are clear cut: it usually takes a while to get things right. Just to prove it, a study from the Netherlands found that high total cholesterol levels were associated with lower rates of Parkinson’s disease, but only in women.

So what to make of all this: infections, allergies and now cholesterol?

To try and understand this, I think that we need to introduce another actor to the stage. Since the early 1950s the medical community has been concerned about a striking concentration of amyotrophic lateral sclerosis (ALS) and Parkinsonism-dementia among the Chamorro people on the island of Guam. A number of lines of evidence have suggested that this group of illnesses has been caused by some neurotoxic agent in the environment, though nobody has been able to work out exactly what it is. One of the most attractive recent theories is that it might have something to do with toxins from Cycas plants. So the idea is that similar cholesterol-containing neurotoxins can come either from Helicobacter or from eating Cycas plants, or animals that have fed on the plants.

There is a complex inter-relationship between LDL- and HDL-cholesterol, and HDL-cholesterol appears to be anti-inflammatory: high levels of HDL-cholesterol are associated with low levels of inflammation. And it has recently been shown that simvastatin may cut the risk of developing Parkinson’s and Alzheimer’s diseases. Not just by lowering cholesterol but from its inflammatory activity.

It may also be that low levels of cholesterol may impair the activity of another factor: one that interests me is coenzyme Q10.

From a practical perspective, this new evidence reinforces a point that I made in Healing, Meaning and Purpose and on this blog: "boosting" one component of the blood or lowering another is not sensible. Whether dealing with cholecterol or immunity, we need to moduate and harmonize all the systems of our bodies and our minds.

Follow our systems for modulating the inflammatory mediators in your body and that alone should – theoretically – reduce your risk of many illnesses.

I shall keep you posted as this story continues to develop.

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