Tuesday, October 30, 2012

Package Labels (the back tells)

   I came upon a bulletin board yesterday,while walking the halls during a class break.  I ended up in the Nutrition area.  The bulletin board was very informative.  I believe its purpose was to offer education or advice on using the nutrition information provided on food packages.  Of course, one of the problems with the information on packages is that it takes a great deal of nutrition knowledge and time to fully process.  These are two things that the general public is short on (time and nutrition knowledge)
   The part of the bulletin board that caught my attention had to do with one of the front of pack systems used voluntarily by a manufacturer.  It was shown on a product that I love and have shared on the blog;  Blue Bunny sugar free ice cream.  The caption, referring to the FOP information was “the front sells, the back tells.”  On the back of the package is the Nutrition Facts Panel and the ingredients list. These are two things that the Institute of Medicine has determined to be hard for consumers to understand and process (read, put together, use).  I agree.  It is also why a front of pack system could be more useful that the back of the pack.  
   The point that the nutrition students were making on the bulletin board is a very good one (which I will explain in a moment). 
   We need the easier to use Front of Pack system, but we need it with the interpretive and guiding criteria as put forth by the IOM.  You might have forgotten what that was.  I will quickly remind you.  All front of packs (under the standards proposed) must have the calorie information boldly highlighted.  The items that the Dietary Guidelines suggest we limit, i.e., saturated (trans) fats, added sugar and sodium are the criteria on which a product is judged.  A product that is low in any of the three areas will get a star  - for a possible total of 3 stars.
   So the Blue Bunny issue from the nutrition students bulletin board was two fold.  The first was that the serving size highlighted on the package was a ½ cup.  I, too, have said that is unrealistic.  The students calculated the calories, sugar, etc for a 1 cup serving size.  The second problem they highlighted was the “no added sugar” claim.  In fact, they said, it is no added table sugar – sucralose.  
    On the back of the package the students had highlighted words that indicate sugar and sugar alcohol.  I might be able to pick some of them out – I believe “tol” and “ose” are word endings that give  clues.      
   But as the IOM states and I strongly support - YOU (we, the consumer) should not have to figure that out – hence the need for standardized FOP systems.
   YUP – we are still waiting for them!

Saturday, October 27, 2012

What a 'Check Up' Gets You

   After writing last nights blog, I was surprised to see an article about the inadequacy of regular health checks. It was quite the coincidence.  I am going to try to link you to the article from here but before I do I wanted to add my two cents.
   After reading the article, it seemed to me that when healthy people get check ups, they end up being treated for some condition.  However,  the treatment does not improve their health or reduce any adverse outcomes.
   For example, a person who is healthy may be placed on a medication to lower their blood pressure or their cholesterol - but neither was actually high enough to be of concern. 
   From this I suspect that the big winners are whoever gets paid for the unnecessary treatment - first and foremost  - drug companies.
   After yesterday's post, you may think I am anti preventative medicine. I AM NOT.  I believe that the best thing we can do is eat well, maintain a normal weight, exercise and avoid tobacco smoke and other chemicals.  Also don't drink too much or spend too much time in the sun without sunscreen.  Oh ok - and use protection when you have sex :)
   Here is the link to the article which was very informative - it is from Medscape and written by Elizabeth DeVita-Raeburn.  

Friday, October 26, 2012

A Reduction in Screenings

   Recently the recommendations for breast cancer, cervical cancer and prostate cancer screenings were updatedChanges have been made for the age at first screening, the target groups for screening and the frequency of screenings.  I am not bothered by this.     
    Interestingly, when my statistics professor finished his lecture on discriminate analyses and "priors" this week, he related the models to health screenings.  Discrimination analysis itself involves separating groups or predicting group status.
   Let me explain.  I promise it won't be painful.  Statistics is MY favorite subject. 
    Statisticians can use information about people (data) to predict an outcome about them, including what "group" they are likely to be in, or a career that they might do well in.  For example, if the statistician knows the scores that 20 people earned on a reading test,  a math test and a personality test, he can create a model that predicts success in a high school class.  In the model, certain scores may matter more than others, so they are weighted.  For instance, the math test has more to do with success in the class than reading score, but both matter.  The statistician puts the numbers in the model and predicts which of the 20 people will do well.  Maybe his model is 70% accurate.  He is only wrong 30 percent of the time.  Then he adds a "prior."  A prior is something we already know about the outcome.  In this case, men do better in the class regardless of  scores.  So he adds gender to the model.  Now his success rate is 80%.  Perhaps he finds another prior and his model becomes 95% accurate.  That is wonderful!  Just think if he were predicting which job applicant would make the most money for a company.  The employer could use his model and find the best employee to hire 95% of the time!  
   My professor said that this type of modeling is very useful UNLESS the thing you are trying to predict does not happen very often.  Maybe the person with combined scores that indicate a good employee is very hard to find.  The model predicts correctly, so most of the time it is just saying that no one in the group will do well.  Remember in our scenario,  the model is wrong 5% of the time.  It may miss someone that would do well, or choose someone who really doesn't do well.  That happens five out of 100 times.  But maybe it takes 1000 times to find ANYONE.
   If it doesn't cost anything to put all the information in a computer and run it every week or so, its not that big of a deal.  We might not find a successful person for a while, but it is not a matter of life or death!

Something else to consider:
    When something is rare, the chance of having a false positive is greater than having a true positive.  The model says someone will do well, when they will not.  Improving the model can increase the number of false negatives, too.  The model says the persons will not do well, but they really would have. 
   If it costs hundreds of dollars to run ONE person through the model and you only find a match on the 10,000 try... it is an accurate and useful model, it just doesn't make sense to use it all the time.
   Believe it or not, breast, cervical and prostate cancer are rare.  Testing every person, every year, is not cost effective because we don't find many cases and we find more false cases than true casesFalse cases lead to unnecessary follow up tests and lots of stress.
   Of course, the cost of missing a true cancer can be a matter of life or death. That is the false negative case.
   We have to consider how often that really happens?  How many times do we say that someone does not have cancer when they really do - in 10,000 tests?  
   I do not know the answer. I believe that over time we have learned that we are finding more "not real" cases because the cancers are so rare. 
   I think that having a screening every 2-3 years instead of every year, is better than not having the screenings at all.  Its an ok compromise for me.

BTW - thinking of weighting cases and cancer.  We know that certain things add to our risk of cancer, e.g., poor diet, overweight, lack of exercise, chemicals, cigarette smoking... guess which one has the greatest "weight" in our prediction model - SMOKING.
and NO, I did not keep that simple. Sorry.

Thursday, October 25, 2012

HPV Vaccine

   In clinical research trials, scientists study the safety of a drug, medical device or vaccine and its efficacy.  Efficacy can be thought of this way:
   Under the ideal situation where a specific type of person uses the drug/device exactly as the researcher/developer intended at exactly the right dose, efficacy measures the extent to which the medicine or device does what the developer thought it would do.  Safety is more obvious.  The goal in the safety trial is for the drug or device not to kill anyone.  Nor should it cause serious harm or side effects that are greater than the positive benefit.
   Clinical trials tell us a lot about both safety and efficacy.  But they are better at uncovering side effects that the greater public might experience than at confirming effectiveness. 
   When you or I take the drug or use the device under less than ideal situations, its effectiveness is considered. Drugs and medical devices continue to be studied for several years after they come to market. They are studied in the overall population.
   Last week I completed a short continuing medical education activity (CME) on HPV vaccines.  It was offered through Medscape.  I learned that the real life common side effects occur in a small number of persons and are not severe.  They include same day fainting or dizziness and delayed skin rash.  In the same activity, I learned that there is no evidence that one cervical cancer case has been prevented by this vaccine.  That was a curious point to make and it wasn't followed up with a review of that research.  However, Medscape  is a peer reviewed website so I feel that the statement was true.  
   My take away was that the vaccine is not harmful, but also may not be effective.  It is likely that the efficacy (confirmed in the clinical trial) was based on the age of the person receiving the vaccine and that they received all three doses.   
   Whether or not you choose to get this vaccine, if you are a woman, a pap smear every 3 to 5 years is necessary.  The pap smear can detect changes in the cells around the cervix which might indicate a pre cancerous condition.

Wednesday, October 24, 2012

Good Riddance Radiation

    I was so happy when I heard about this a week ago that I almost stopped my exams to blog about it.
   The airport scanners that use radiation - ones I have railed against in the pages of this blog site - are getting the boot.  Here is a link to just one of those examples.
   I would love to say that the complaints and concerns of people like me who value the health of the public and recognize that any amount of radiation is a risk, made this happen.  We did not.  Instead, the machines have been difficult to maintain, have technical glitches and may be improperly used by some airport employees.  Here is a short story about the removal of the machines from NYC airports.
   As they go, the reason doesn't matter so much - as long as they go.  Unfortunately, some of them are being recommissioned to smaller airports where I suppose the staff have the time to deal with problems. 

Tuesday, October 23, 2012

Energy Density, Diet Quality and Eating Out

    A diet low in energy density is recommended in the Dietary Guidelines for Americans and by most nutrition scientists.  Energy density is the amount of calories per gram in a food(here are 2 past posts written about energy density and the DGA)
    It best to fill our plates with foods that contain less than 1 calorie per gram, with a few exceptions. Lean proteins (e.g., peanut butter, fish, legumes), whole grains (e.g.,wheat flour, bulgar, quinoa) and mono/poly unsaturated fats and omega 3 fatty acids (e.g., olive oil, salmon) have 2 to 3 calories per gram.  More commonly,  foods with high energy density are composed of unhealthy solid fats (trans fats and saturated fats) and sugar.  On average, meals prepared away from home are higher in energy density than meals prepared at home.  This is likely due to the frying, sauteing and use of sauces, condiments and sugars (and red meat; beef and pork).
   The quality of a person's overall diet can be assessed based on its adherence to the Dietary Guidelines and its energy density.  This is usually done with the Healthy Eating Index or the Alternative to the Healthy Eating Index.  Read more about them here.
   A majority of Americans, Britains, Australians, Mexicans and such  have diets that are poor or need improvement based on the indexes.  
   While reading a report from the US Economic Research Service (Variyam, 2005), I came across a chart that combined these factors.  The findings were quite telling.  People who were classifed as having a good diet spent more money eating away from home than those with diets lesser quality diets (poor or needs imrovement).  However, the people spending less money on meals away from home were actually consuming MORE of their daily calories from those meals.  They also ate meals that were higher in energy density than the good diet group both away from and at home.
   You can draw your own conclusions, but here was my take away:
The cheapest foods have the most energy density.  A grilled fish dinner with steamed vegetables will have lower energy density than a burger and fries or fried chicken and mashed potatoes and the fish dinner will cost several dollars more.  Less money spent, worse food consumed.  Those who get more of their calories from away from home foods have higher energy density and poorer diet quality.

Sunday, October 7, 2012

The Best Way to Lose Weight

I want to be sure that I didn't  mislead or confuse you, by referring to this old NHIS question in the last post.

In your opinion which of these are the 2 best ways to lose weight

 Eat fewer calories
 Take diet pills
 Increase physical activity
 Eat NO fat
 Don't eat at bedtime
 Eat grapefruit with each meal
My point was to draw your attention to how things have changed in the last 40 years and what we know today.

In the above list and in any list, the best way to lose weight is to reduce the number of calories consumed.  You must eat less to lose weight - and not because you took a diet pill or because there was grapefruit on your plate.  Limiting saturated fat is a good idea, avoiding trans fat is important. Including healthy oils from plant and fish sources is essential.  The only right answer in that list was related to calories.  BTW, the body doesn't know what time you eat.

 But about the physical activity:

A person who is physically active is less likely to become overweight than a person who is inactive.  A person who is physically active is more likely to keep lost weight from returning than someone who does not engage in physical activity.
A person who meets the recommended levels of physical activity is less likely to die from any cause (over a set time period) than those who do not.  People who exercise regularly are also less likely to become ill from heart disease and some cancers.