Saturday, 8 December 2012

What is Common Today is not Normal

Many believe that it is normal for our health to decline as we age.  Most people will have a few cavities by the time they are 20, and are missing a few teeth by the time they are 60.  30% of deaths in Canada are from Cancer and 28% are from Heart Disease and Stroke.(1)  9 million Canadians are suffering from diabetes or prediabetes. (2)  Alzeimers rates are expected to more than double in the next 25 years.(3)  Arthritis, sore muscles and decreasing energy are seen as a normal part of aging.  

I would argue that although these ailments are common today, they are not a normal part of human aging.  Weston Price was a dentist who travelled the world in the 1930’s studying tooth decay.  His book, “Nutrition and Physical Degeneration”, was the result of his travels.   He studied native people who were still eating their traditional diets in the same area as native people who have adopted modern foods.  He found that people eating their traditional diets were almost immune to tooth decay, while people eating modern foods like flour, sugar and canned fruit experienced high rates of tooth decay.  0.09-0.38% of teeth in people eating a traditional hunter gatherer diet had been attacked by dental caries.  13-40% of teeth in people eating a modern diet had dental caries. (4)  These primitive people didn’t have access to dentists and had never even seen a toothbrush, yet they had almost no tooth decay.  Dr. Price found that even the 70 year old elders eating traditional diets still had all their teeth and did not have tooth decay.  How many 70 year old's in our society can say the same thing?  Dr. Price brought a camera with him and was able to take pictures of the people he studied.  You
don’t even have to read his book, all you have to do is look at the photos.   The four photos on the left and one on the top right below are of people eating their traditional diets, while the other three are consuming modern foods. 

Other frontier doctors also recorded their findings on disease in primitive populations.  In 1913 Albert Schweitzer established a missionary hospital in Western Africa.  He wrote:

 “On my arrival in Gabon I was astonished to encounter no cases of cancer....I cannot, of course, say positively that there was not cancer at all, but, like other frontier doctors, I can only say that if any cases existed they must have been quite rare”(5)

Another quote from the early 1900’s in the Western United States.  

“Chas M. Buchannan .... practiced fifteen years among two thousand Indians with an average life expectancy of fifty-five to sixty years and saw only one case of cancer” (6)  

Similar findings were reported for other diseases.

“Most of these historical observations came from colonial and missionary physicians like Schweitzer and Hutton, administering to populations prior to and coincidental with their first substantial exposure to Western foods.  The new diet inevitably included...sugar, molasses, white flour and white rice.  Then diseases of civilization, or Western Diseases, would appear: obesity, diabetes mellitus, cardiovascular disease, hypertension and stroke, various forms of cancer, cavities, periodontal disease, appendicitis, peptic ulcers, diverticulitis, gallstones, hemorrhoids, varicose veins, and constipation”(7)

Some have argued that people just didn’t live long enough in these populations to get cancer, but the low life expectancy was due to infant death, infectious disease and trauma.  If you made it into adult hood you had a good chance to live into your 60’s and 70’s. (8)  Rates of childhood disease are increasing as well, which has nothing to do with low life expectancy.  We used to classify diabetes as either juvenile or adult onset diabetes.  We had to change the names to type 1 and type 2 diabetes because too many kids are getting adult onset diabetes!  

The latest research is pointing toward oxidation and systematic inflammation as being a major contributor to common ailments of aging.(9)  This constant inflammation impairs the ability of our immune system to function properly.  Our dietary and lifestyle choices play a role in this process.  Quality of food, sleep and exercise, as well as stress, can all impact the amount of inflammation and oxidation we have.  Make the wrong choices and you will suffer the “common” ailments of aging, make the right choices and you can live a “normal” long, healthy and active life.  

(5)    Schweitzer 1998:136-39
(6)    Isaac Levin: Cancer Among the North American Indians and Its Bearing upon the Ethnological     Distritution of the Disease
(7)    Gary Taubes, Good Calories Bad Calories:91

Saturday, 10 November 2012

Why Nutrition Science is so Bad

When I first started looking into nutritional science, I was shocked at how badly it was done.    To be fair, nutrition science if very difficult.  There are so many lifestyle and nutrition choices that can have a positive or negative influence on health, that it is hard to isolate the effect of any one food or group of foods.  There are two main types of studies; Observational (Epidemiological) studies and Controlled Experiments.  Tom Naughton has a really good video called “Science for smart People”  that explains the difference in an informative and humorous way.

The gold standard of science is the controlled experiment.  In a controlled experiment, you hold all variables constant except for the one variable that you are studying.  For example, if you wanted to study the effect of a fertilizer on growing plants, you would plant two groups of the same seeds.  You would use the same soil, same size pot; put the pots in the same area where the temperature and light exposure are the same, and give them the same amount of water.  You would put fertilizer in one but not the other.  If the plants in the fertilized pot grow faster and larger, then this would support your hypothesis that fertilizer helps plants grow.  

It is very hard to do this in a nutritional study.  The only way to be sure of the quality and quantity of food consumed, would be to lock people in a metabolic ward where food could be controlled.  You would have to weigh and measure all the food served, as well as all the food that wasn’t eaten.  Since most people are interested in being healthy for the rest of their life, and not just for the next 6 months, these studies would have to last 10 to 20 years to be really meaningful.  Not too many people would volunteer to be in a study that would lock them in a metabolic ward for 20 years!  (well, maybe Al Bundy would volunteer).  Even if you could do a study like this, it might not be relevant to the real world.  In a metabolic ward you have to stick to the diet; there is no other food choices.  In the real world, there are food choices on almost every street corner.  People have to be able to stay on a nutritional lifestyle long term for it to be useful. 

Very few controlled studies are done in nutritional science.  Almost all the studies we hear about are observational studies.  In these studies information is gathered on what people eat, usually with food frequency questionnaires.  These people are followed for a number of years and their health outcomes are observed.  Correlations are made between the food people ate and their health outcomes.  These types of studies have many limitations, the biggest being that they cannot provide any information on cause and effect.  Observational studies are useful for coming up with a new hypothesis, but then the hypothesis has to be tested in a Controlled Experiment.  A couple hypothetical studies from Tom Naughton's video might explain why this is.

If we were to do a study of the BMI of marathon runners compared to the BMI of the average person, you might find that running marathons is correlated with a lower BMI.  The conclusion of the study could say that running in marathons was linked, or correlated, or associated with a lower BMI.  They could not say that running in marathons causes you to become lean and have a lower BMI, even though most people hearing about this study would think that running marathons does cause people to have a lower BMI.  It conforms with our preconceived notions about exercise and weight, so we assume that causation is proved by the study.   If we look at another hypothetical study, it will illustrate why this is not the case.  If we did a similar study but used professional basketball players and height, we would find that playing basketball is correlated with being taller than the average person.  Does that mean that playing basketball causes you to grow taller?  If you are 5’6” and want to be 6’ tall, can you play basketball for a few years and expect to  grow?  Of course not!  Playing basketball doesn’t cause you to grow taller; it’s just that if you are tall you are more likely to play professional basketball.  The same logic can be used in the other study: Running marathons might not make you lean, it’s just that lean people are more likely to run marathons.  

When something in a study (A) is correlated with something else (B) it is easy to jump to the false conclusion that A is causing B.  A may or may not be causing B, as there is no way to know just from an observational study.  A may be causing B.  B may be causing A.  A third variable, C may be causing A and B.  This third variable C is what is called a confounding variable.  An example of this is that ice cream sales in Florida are correlated with shark attacks.  Does this mean that eating ice cream causes shark attacks?  Maybe the sharks like the ice cream dripping down your chin so they are more likely to attack.  Of course this is silly.  When it is hot, people eat more ice cream and they also go swimming more, which leads to more shark attacks.    Observational studies are full of confounding variables.  There are two main groups of people that influence the outcomes of nutritional studies.  There are people who are very health conscious and do whatever they can to be healthy, and those that do not care about their health and make food and lifestyle choices that are purely based on giving them pleasure.  People who are health conscious tend to have better health than people who are not health conscious.  They follow the health advice that has been generally given the last 40 years; they smoke less, drink less alcohol, exercise more, take vitamins, eat less calories, eat less sugar, eat less refined processed foods, and eat more vegetables.  Any one of these variables could be contributing to their good health, but from an observational study you can’t tell which one.  You would need a controlled experiment to do that.   

Another problem with observational nutritional studies is that the data collected is not very reliable.  It is usually collected using food frequency questionnaires.  In these studies people are asked to recall what they ate in the last day, month, year, or even four years.  You can find an example of a questionnaire here.  Most people can’t remember what they ate last Tuesday, let alone what they ate three years ago.  People who see themselves as healthy tend to overestimate foods they consider healthy and underestimate foods they consider unhealthy. Who wants to admit that their breakfast consisted of twinkies and oreos?  If the data that the study is based on is not accurate, then how useful is the study?

Some scientists can have such a strong belief in what the outcome of their study will be that they become biased.  Since there are so many confounding variables, you can make the outcome of a study say pretty much whatever you want it to say.  Most studies will try and account for these variables, but it is almost impossible to know exactly how much of a part each one played in someone’s health.  Some researchers will use a third variable to link two items when there is no direct link.  A good example of this is saturated fat, cholesterol and heart disease.  Many studies (such as Dr. Jolliffe's Anti-Coronary Club experiment mentioned here) will claim to show that saturated fat causes heart disease even if the data in their data shows that people who ate more saturated fat had a lower incidence of heart disease.  They do this by saying that saturated fat intake was associated with higher cholesterol, which is claimed to be a marker for heart disease. (Even though it has never been proven that high cholesterol causes heart disease)

This is why we get so many mixed messages from the so called “nutrition experts”.  The way Observational studies are reported, it gives the idea that they determine cause and effect when they really only show correlation. In one group of people a certain food may be correlated with high cancer rates, in another group they may be correlated with low cancer rates.  The truth may be that the food has NO impact on cancer rates.  As long as we remember the limitations of the study we won’t get sucked into these false assumptions.  So the next time you hear about the latest study telling you to stay away from a certain food, or that another food is a miracle cure, remember that 99% of these studies don’t actually prove anything.  

It is time to stop funding these types of observational studies.  How many studies do we need that give sensational headlines but do not add to our knowledge.  We have enough hypotheses about health and nutrition.  We need to start doing controlled experiments to find out which hypotheses about diet and nutrition result in healthy outcomes.  With obesity related diseases and health care costs skyrocketing, we need to find these answers now. 


Thursday, 1 November 2012

Flu Season - Vaccine or Vitamin D?

Flu Season – Vaccine or Vitamin D?

With flu season getting closer we are starting to hear the advertisements advising everyone to get a flu shot.  Medical journals are calling for mandatory flu shots for all health care workers.  I have two questions, 1) are flu shots effective? 2) Is there any better way to protect against influenza? 

Most people assume that flu vaccines are effective but a 2010 Cochrane Collaboration review suggests otherwise.  This description of the Cochrane Collaboration is taken from their website.

 “The Cochrane Collaboration is an international network of more than 28,000 dedicated people from over 100 countries. We work together to help health care providers, policy-makers, patients, their advocates and carers, make well-informed decisions about health care, by preparing, updating, and promoting the accessibility of Cochrane Reviews  

The objective of the 2010 review was to “Identify, retrieve and assess all studies evaluating the effects of vaccines against influenza in healthy adults”    The summary explains some of the limitations of flu Vaccines.

“Over 200 viruses cause influenza and influenza-like illness which produce the same symptoms.....At best, vaccines might be effective against only influenza A and B, which represent about 10% of all circulating viruses.  Each year, the World Health Organisation recommends which viral strains should be included in vaccinations for the forthcoming season”

It is impossible to predict which viral strains we are going to be exposed to in the upcoming season.  Of the possible 200 viruses most flu shots will only offer some protection from 3 virus strains.  It is relatively uncommon for the strains in the vaccine to match the strains we are exposed to.  When they do not match, 2% of unvaccinated people develop influenza symptoms compared to 1% of vaccinated people.  When they do match, the numbers are 4% for unvaccinated people versus 1% for vaccinated.  There is a small decrease in the number of people developing influenza symptoms when vaccinated but the summary noted:

“Vaccine use did not affect the number of people hospitalised or working days lost but caused one case of Guillian-Barre syndrome (a major neurological condition leading to paralysis) for every one million vaccinations”   In their conclusion they stated “There is no evidence that they (influenza vaccines) affect complications, such as pneumonia, or transmission”. 

Another review done at the University of Calgary that looked at vaccinations in health care workers who worked with the elderly and found “there is no evidence that vaccinating HCWs (health care workers) prevents influenza in elderly residents in LTCFs (long term care facilities).”

Almost half the trials studied were funded by the vaccine industry.  “ Studies funded from the public sources were significantly less likely to report conclusions favourable to the vaccines.  The review showed that reliable evidence on influenza vaccines is thin but there is evidence of widespread manipulation of conclusions and spurious notoriety of the studies.”  Industry studies were not only more likely to be positive but they were “published in more prestigious journals and cited more than other studies independently from methodological quality and size”

Proponents of flu vaccines will point to the hundreds of Observational studies that have reported an approximate 50% reduction in all cause deaths in vaccinated seniors compared to unvaccinated seniors.  This topic was reviewed in this paper.  “ a 50% vaccine effectiveness (VE) against death from any cause sounds too good to be true, if only because influenza is related to an average of only about 5% of all senior deaths during winter and the observed impact occurring prior to the season”  

A 50% reduction in deaths when only 5% of deaths are related to influenza indicates possible selection bias in the studies.  When the researches went through the cohort studies showing a 50% VE, they found that “the greatest difference in mortality rates among vaccinated and unvaccinated seniors in the HMO database studies turned out to occur in the months before the influenza epidemic period, and strategies commonly used for adjustment of bias in cohort studies were counter-productive”  The fact that the studies show that the vaccine prevented more deaths prior to flu season than it did in flu season demonstrates vaccination selection bias. When they dug further they found the probable cause of the confounding.  There is a subset of frail and terminally ill seniors who are less likely to become vaccinated because of their deteriorating health.  These unvaccinated seniors have a much higher mortality rate which confounds the results. 

They also noted a 2003 CDC study  that found that while vaccination coverage in the 80’s and 90’s quadrupled, influenza-related mortality rates increased at the same time.  This is an observational study, so it can find correlations, not cause and effect, but it is still interesting to note that mortality rates increased along with vaccination rates.  

After searching through all the scientific data these researchers could only find one Randomised Controlled trial that showed a small improvement in influenza symptoms but no significant  effect on hospital days, working days, complications or transmission.  They were not able to draw and conclusions from the other cohort studies due to the general low quality of the studies or presence of biases.  Randomised Controlled Trials need to be done to demonstrate improvements in outcomes like hospitalisation's, work days missed, complications and transmission.  With the science available today it is hard to make a recommendation on voluntary vaccinations and is even more difficult to reconcile mandatory vaccinations.  

Some of the reasons people may not want to take unnecessary vaccines is because of the ingredients in the vaccines.  Multi dose influenza vaccines usually contain thimerosol which is a mercury containing compound.  They may also contain aluminum oxide and formaldehyde.  We are told that they are in very small amounts that are safe. Macrophagic myofasciitis (MMF) has been linked to aluminum oxide used as an adjuvant in some vaccines.  The question is, do we want any amount of a neurotoxic metal injected into our bodies if it not going to result in meaningful benefits?  These adjuvants are used to stimulate the immune system to provoke a larger response to the vaccine.  Could these repeated artificial stimulation's impacting allergies and autoimmunity?  We don’t know the answers to these questions. 

A simple and maybe even more effective way of dealing with flu season may be to make sure you have adequate levels of vitamin D.  This 2010 randomised controlled study showed that children taking vitamin D supplements were 42% less likely to get the flu.  Vitamin D’s effects on the innate immune system appears to “both enhance the local capacity of the epithelium to produce endogenous antibiotics and – at the same time – dampen certain arms of the adaptive immune response, especially those responsible for the signs and symptoms of acute inflammation, such as the cytokine storms operative when influenza kills quickly.”

A 2006 paper appearing in the journal Epidemiology and Infection made the following observations.

“1. Why the flu predictably occurs in the months following the winter solstice, when vitamin D levels are at their lowest,

2. Why it disappears in the months following the summer solstice,

3. Why influenza is more common in the tropics during the rainy season,

4. Why the cold and rainy weather associated with El Nino Southern Oscillation (ENSO), which drives people indoors and lowers vitamin D blood levels, is associated with influenza,

5. Why the incidence of influenza is inversely correlated with outdoor temperatures,

6. Why children exposed to sunlight are less likely to get colds,

7. Why cod liver oil (which contains vitamin D) reduces the incidence of viral respiratory infections,

8. Why Russian scientists found that vitamin D-producing UVB lamps reduced colds and flu in schoolchildren and factory workers,

9. Why Russian scientists found that volunteers, deliberately infected with a weakened flu virus - first in the summer and then again in the winter - show significantly different clinical courses in the different seasons,

10. Why the elderly who live in countries with high vitamin D consumption, like Norway, are less likely to die in the winter,

11. Why children with vitamin D deficiency and rickets suffer from frequent respiratory infections,

12. Why an observant physician (Rehman), who gave high doses of vitamin D to children who were constantly sick from colds and the flu, found the treated children were suddenly free from infection,

13. Why the elderly are so much more likely to die from heart attacks in the winter rather than in the summer,

14. Why African Americans, with their low vitamin D blood levels, are more likely to die from influenza and pneumonia than Whites are.”

These are observations so they cannot prove cause and effect but they point to the need for Randomised Controlled Trials to be done on the health benefits of Adequate vitamin D levels.
Serum Vitamin D levels can be tested but they are not covered by BC Medical.  It is my opinion that millions of dollars would be saved in health care costs if BC Medical paid for Vitamin D tests and everyone had adequate levels of vitamin D.  If you want to get tested ask your doctor for a  25-hydroxyvitamin D, or 25(OH)D.  There is some debate about what the ideal level of serum vitamin D is but a level of around 50 nmol/L seems to be a common range with most experts.

Most people today need to supplement with Vitamin D3.  It is very hard to get from our diet, historically we made our own Vitamin D with exposure to the sun. Most people work indoors and do not get adequate sun exposure.  When we are in the sun we are told to cover up and put on sunscreen, which blocks the production of vitamin D.  Sun burns are definitely dangerous, but responsible sunbathing, 10-15 min/day without sunscreen, can be a very healthy way to get your vitamin D.  Even if you do get adequate sun exposure in the summer the sun is not high enough in the winter to get adequate vitamin D if you live in Canada, so some supplementation is recommended.  The vitamin D Council states that it is safe to supplement with up to 10 000 IU of vitamin D3/day and recommends adults take 5 000 IU/day.

Reducing systematic inflammation and having adequate vitamin D levels, along with its cofactors Vitamin A and K2, strengthens your immune system. This not only reduces your risk from influenza, but may also have to following benefits:
-protect the common cold
-help prevent and in some cases treat cancer
-increase bone health
-increase dental health
-protect against cardiovascular disease

With all the benefits of Vitamin D I see no reason not to supplement during the winter months.  A more prudent method of dealing with influenza in health care workers might be to test Vitamin D levels and supply supplementation.   This applies if you choose to get the flu shot or not.  Eating a diet that does not cause inflammation and getting enough sleep along with maintaining adequate vitamin D levels will help you make it through flu season.