Friday, May 17, 2013

Glycemic Index vs Glycemic Load


Glycemic Index
Glycemic index (GI) is a ranking of carbohydrate containing foods based on their immediate effect on blood glucose (blood sugar) levels. Carbohydrates which break down quickly during digestion have the highest glycemic indexes. The blood glucose response to these carbohydrates is fast and high. Carbohydrates which break down slowly, releasing glucose gradually into the blood stream, have low glycemic indexes.  The GI of glucose is 100 and everything else is compared to this.  Although each food is given just one number its GI can actually vary depending on variety, ripeness, cooking method and length of storage.

Glycemic Load
While each food has a GI ranking, glycemic load (GL) takes into account the quantity that is eaten by factoring in the amount of carbohydrate in a typical serving.  For example, watermelon has a high GI, but an average serving does not contain much carbohydrate (it is mostly water) so it has a low glycemic load.  For a serving of food, a GL greater than 20 is considered to be high, 11 to 19 is medium and 10 and below is low.  GL is defined as the grams of available carbohydrate in the food x the food’s GI/100. 

The Diet/Insulin Connection
Insulin is a hormone that responds directly to what you eat. Among its many roles in the body, insulin regulates fat metabolism and controls blood sugar levels. In an optimal state, the body maintains the blood sugar level in a fairly narrow range: not too low (hypoglycemia) and not too high (hyperglycemia).

Choosing low GI and GL foods means a smaller rise in blood glucose after meals. These foods can keep you feeling fuller longer and can improve the body’s sensitivity to insulin. They can also help people lose weight.

Eating a low GI or low GL diet has been found to be beneficial not only for diabetes and weight loss but also metabolic syndrome, insulin resistance, heart disease and cholesterol.  Eating high GI foods has been linked to obesity.

As a general rule, if you eat a varied diet trying to stick mostly with low to medium GL foods you will have the best results.

If you have questions about GI or GL, contact your local naturopathic doctor.

Friday, May 10, 2013

Having Trouble Sleeping?


As we are sleeping our bodies have many important jobs to do.  This is the optimum time for growth and rejuvenation of the immune, nervous, skeletal and muscular systems.  This is when muscle growth, tissue repair and protein synthesis occur.  Our bodies are healing, as this is the best time for white blood cell and antioxidant functioning.  We also secrete hormones such as growth hormone and melatonin and clear the build up of substances like adenosine.  Sleeping is also the key time for brain development and memory processing. 

Although we still don’t know everything our bodies do while we are sleeping, we do know what happens when we don’t get enough sleep.  Lack of sleep can more than double the risk of death from cardiovascular disease.  It can also be a risk factor for weight gain, high blood pressure and Type 2 diabetes.  Sleep difficulties are associated with depression, alcoholism and bipolar disorder.  Sleep deprivation affects judgment, mood, ability to learn and retain information and increases the risk of accidents and injury.  When sleep deprived our white blood cell count decreases.  In a study, animals deprived entirely of sleep lost all immune function and died within weeks.  Sleep problems have even been associated to digestive problems such as inflammatory bowel and Crohn’s disease.

So what is enough sleep? One study found that people who sleep six to seven hours each night live the longest.  But this is only if people wake naturally instead of with an alarm clock.  It is generally accepted that you have had enough sleep if you have no periods of tiredness through the day.

If you suffer from sleep problems the first thing to start with is to look at your sleep hygiene.
  • Keep the TV, computer, tablet, phone, anything with a bright screen out of the bedroom.  Artificial light can shift your circadian rhythm.
  • Sleep in complete darkness.  Even a little light can stop the creation of sleep hormones such as melatonin.
  • Avoid stimulants such as coffee, tea or energy drinks after noon.  Some people can take as long as 18 hours to clear caffeine from their system so should not drink it at all.
  • Try using an alarm clock with sleep stage monitoring.  This monitors what stage of sleep you are in so you are woken during a lighter sleep rather then a deep sleep.
  • Avoid alcohol.  Although this will initially aid going to sleep it gives a worse quality sleep and you can wake in the night.
  • Most sources say a routine is very important.  Counter to this is the theory that you should only go to bed when you are tired.  Try both and see what works best for you.
  • And last but certainly not least, exercise and diet. Regular exercise and a healthy diet will improve your sleep along with most other ailments.

If you are still having problems with your sleep some supplements may be helpful in the short term, but talk to your naturopath before trying anything.


References

Ferrie JE, Shipley MJ, Cappuccio FP, Brunner E, et al. A prospective study of change in sleep duration: associations with mortality in the Whitehall II cohort. Sleep 30 (12): 1659–66.

Harvard Medical School: Healthy Sleep
http://healthysleep.med.harvard.edu/healthy/matters/benefits‐of‐sleep/why‐do‐ we‐sleep

Thase M. Depression and sleep: pathophysiology and treatment. Dialogues in clinical neuroscience 8 (2): 217–226.

Rowland R. "Experts challenge study linking sleep, life span". CNN.