March 14, 2012
Fitness or Fatness?

A few questions ago someone asked me how to find creditable journal articles.  Write this name down, Steven N. Blair.  One of the number one, if not the #1 person, for exercise interventions and large popluation studies in fitness.  His group just published a new article that I will highlight for you below.

Introduction:  How fit someone is as well as how fat someone is are both strong predictors of cardiovascular disease (CVD) risk factors and mortality.  Some studies suggest that being fit can attenuate the harmful effects of being fat.  That is to say, you can be overweight but as long as you are fit, it helps eliminate risk factors of CVD.  However, this group points out that there is a continuous change between being fit or fat, which could skew the results.  Therefore, the purpose of this study was to examine the independent and combined associations of changes in fitness and fatness within the development of risk factors of CVD; hypertension, metabolic syndrome, and hypercholesterolemia.

Results:  After a 6 year follow-up, participants (all 3,148 of them) who maintained or improved fitness had 26% and 28% lower risk of hypertension, 42% and 52% lower risk of metabolic syndrome, and 26% and 30% lower risk of hypercholesterolemia compared with those who last fitness.  On the other hand, those who increased in percent body fat, had 27%, 71%, and 48% higher risk of hypertension, metabolic syndrome, and hypercholesterolemia.  Interestingly, every 1-MET improvement in fitness between the beginning of the study and the follow-up was associated with a 7%, 22%, and 12% lower risk of subsequent incidence of hypertension, metabolic syndrome, and hypercholesterolemia.  On the fat side, every unit increase in BMI or percent body fat was associated with increases in higher risks of these CVD risk factors.  Similar results were found when looking at just waist circumference. Finally, both losing fitness regardless of fatness and gaining fatness regardless of fitness change were associated with a higher risk of developing metabolic syndrome.

Discussion/Conclusion:  Maintaining a certain level of fitness or improving on that level seems to alleviate, although not completely terminate, some of the negative effects of fat gain.  In addition, losing body fat can reduce CVD risk factors associated with a loss in fitness.  It is important to note that both, separately, are important risk factors in the development of CVD.

My input:  Keep in mind when reading these results that they are correlations and that does not give us a cause-effect relationship.  Other than that, I’m going to let Dr. Blair give you his final input this time (I urge you to please click this link) on this topic because he says it so much better than I could:

"My recommendation is to focus on good health habits, no matter what number you see on the scale. Give fruits, vegetables and whole grains a major place in your daily diet. Be moderate about fat and alcohol. Don’t smoke. Work on managing stress. Perhaps most important, get out
of your chair and start moving for at least 30 minutes every day.”

Lee et al J Am Coll Cardiol. 2012 Feb 14;59(7):665-72.

January 16, 2012
Excessive fructose intake induces the features of metabolic syndrome in healthy adult men.

Fructose, friend or foe?  It can be so beneficial to endurance athletes but so detrimental to the sedentary person.  These findings may alarm you.

Introduction:  As stated previously during sugar month, large fructose ingestion is linked with an array of health problems.  In this case, researchers link it to the metabolic syndrome, which consists of insulin resistance, dyslipidemia, abdominal obesity, and elevated blood pressure.  The metabolic syndrome often precedes the development of Type 2 diabetes.  Some of these effects are not found with glucose or diets consisting of starch.  Fructose and glucose metabolism differ and one of the consequences is depletion of ATP and production of inflammatory mediators.  The breakdown eventually leads to the production of uric acid, which may have a role in insulin resistance.  Therefore, the researchers are trying to use a drug, allopurinol, as a way to reduce uric acid and see if this can reverse the symptoms of metabolic syndrome after fructose consumption.

Methods:  Participants were 74 males who ingested 200g daily of fructose sipped throughout the day for a total of 2 weeks.  One group received the drug allopurinol and the other did not.

Results:  The following showed significant differences from baseline in regards to fructose ingestion:

  • Increase in ambulatory blood pressure with subtle greater increases in diastolic blood pressure throughout the day (number of participants who fit the criteria of metabolic syndrome for this went from 9 at baseline to 21)
  • Mean increase in fasting triglycerides
  • Reduction in HDL cholesterol
  • Increase in patients with fasting glucose meeting the criteria for metabolic syndrome ( >5.5 mmol/L)
  • Increase in fasting plasma insulin
  • Worsening of liver function tests

In regards to the group that consumed the drug (allopurinol) to decrease uric acid there were significant changes found to:

  • Protect against increases in systolic and diastolic blood pressure as well as mean arterial pressure
  • Protect against metabolic syndrome (32% participants had it before and only 34% after as compared to the fructose only group at 19% to 44% after two weeks)

Discussion/My input:  The first thing you are probably thinking is, “Nick, who would drink 200g of fructose per day, this study is not practical.”  Well, here is an alarming fact; the upper quintile of Americans consume more than 110 g of fructose daily either as additional sugar or as high-fructose corn syrup.  That is pretty close and these changes happened in only 2 weeks!  As far as the drug, it may be something included in the future to combat the metabolic syndrome; however, these results cannot be related to obese individuals or even women.  The researchers state that fructose metabolism can vary between genders.  Once again, fructose might not be the sole reason for the obesity epidemic, but it does lend credence to that notion.

Perez-Pozo et al Int J Obes (Lond). 2010 Mar;34(3):454-61