Adult onset type 2 diabetes (NIDDM) (Part 2)

A useful concept when looking at the effect of carbohydrates on blood sugar is glycemic index (GI).  This is a measure of how much different foods increase a person’s blood sugar.  This is expressed as a number generally between 1 and 150.  The standard for comparison is pure glucose which has a GI of 100.  The higher the number, the more a food will raise your blood sugar (which is a bad thing).  Foods can be classified as low GI (55 or less), medium GI (56 to 69) or high GI (70 and above).  A related concept is glycemic load (GL) which combines both the quality and quantity of carbohydrate into one number and is probably the best way to predict the effect of different foods on your blood sugar.  For one serving of food, a GL value of 10 or less is low, 11-19 is medium, and greater than 20 is high.  This website contains a free searchable database of thousands of foods where you can look up their glycemic index and load as you try to improve your diet to prevent diabetes.

Another type of food which it is important to avoid when trying to prevent diabetes are those with highly refined carbohydrates or large amounts of added sugars.  One useful way to do this is by looking at the nutrition label on the side of most packaged foods.  Here is a 4 minute video that explains how to do this and which explains the ‘five to one fiber rule’.  While I agree with the five to one fiber rule, division in your head can be tricky – a simpler approach can be to take the grams of carbohydrate and subtract the grams of fiber (eg for Wonderbread: 20g – 2.7g = 17.3g).  The result is the amount of ’empty carbohydrates’ in the food.  The goal is to have this number as low as possible, ideally less than 12g per serving.  I find this to be a very easy to use and practical approach which can be applied to almost all foods (eg drinks, breakfast cereals etc).  For some other tips on reading nutrition labels, see here.

If you have been told you are a pre-diabetic, you need to understand that in addition to losing weight (goal body mass index [BMI] of less than 25) you need to exercise (this increases how responsive your body is to insulin).  A recent study (1) of 2278 new cases of diabetes showed that engaging in weight training or aerobic exercise for at least 150 minutes per week was independently associated with a lower risk of type 2 diabetes of 34% and 52% respectively.  Men who did both for 150 minutes per week had the greatest reduction (59%).  Click here for a excellent video on additional benefits of exercise.

In addition to the above, certain foods can help you prevent diabetes:

1. One of my favorites is flaxseed (see here) since it is also helpful in breast and prostate cancer and is an excellent source of omega 3 and fibre.
2. Another food is nuts.  This study followed 83,818 women aged 34-59 years of age for 16 years to see if their intake of nuts and/or peanut butter lowered their risk of type 2 diabetes.  In comparison to those who never/almost never consumed nuts, women who took 5 or more oz per week were 27% less likely to develop type 2 diabetes (P<0.001 for trend). This association was present after adjustment for dietary fat/fiber, weight, smoking, alcohol use and other diabetes risk factors.  A similar trend was also seen with consumption of peanut butter with those consuming more than 5 oz per week having a 21% lower risk of type 2 diabetes (P for trend < 0.001). You can see the whole paper by clicking on reference (2) below. [For my two cents worth, I’d suggest you have raw natural peanut butter without salt or sugar].  See here (& here) for more information on the benefits of nuts.
3. Certain whole fruits (but not fruit  juices) have been found to be associated with a lower risk of getting NIDDM.  A large prospective cohort study followed 187,382 men and women for 18-24 years (total of 3,464,641 person-years of follow-up) and looked at the onset of new cases of type 2 diabetes. While the overall effect of whole fruits was modest with 3 servings a week decreasing the risk of diabetes by only 2% (P<0.05), much larger effects were noted for specific fruits. Consumption of blueberries (3 servings/week) was associated with a 26% (P<0.05) lower risk of type 2 diabetes .  Significantly lower rates of diabetes were also found with 3 servings/week of the following fruits (% reduction): Grapes & raisins (12%), prunes (11%), apples and pears (7%), bananas (5%), grapefruit (5%).  No significant protective effect was found for peaches, plums, apricots, oranges, strawberries, and cantaloupe

Dr Greger wrote an excellent article about what NOT to add to white rice, potatoes, or pasta that explores what has fueled the explosive rise in the rate of diabetes in China in the last 20 years.

Here’s what the Harvard School of Public Health has to say about Preventing Diabetes.

And here is a nice six step plan for how to implement this approach.

More information on diet and diabetes from the Physicians Committee for Responsible Medicine here.

For those who prefer audio, here is an excellent podcast on preventing diabetes by Dr Greger.

And here is an excellent video highlighting the role of BPA (bisphenol A) in obesity.

Here is  good 5min video on the role of saturated fat in diabetes (more info here):

While carbohydrates contribute to obesity which can lead to diabetes, it is not as simple as “Sugar causes diabetes” and now looks like excess fats in our diet (eg from fast and processed foods) probably play a central role (3).  See here for an excellent discussion of this.

Click on the image below to see a recent (March 2017) talk I gave on ‘Food as Prevention for Obesity and Diabetes’:

Click here for even more information on diabetes.

References

1. A prospective study of weight training and risk of type 2 diabetes mellitus in men. A Grontved, EB Rimm et al. Archives of Internal Medicine 2012;172(17):1306-12
2. Nut and Peanut Butter Consumption and Risk of Type 2 Diabetes in Women. R Jiang, JE Manson, WC Willett et al. JAMA 2002;288(20):2554-2560.
3. Impaired mitochondrial activity in the insulin-resistant offspring of patients with type 2 diabetes. KF Petersen et al NEJM 2004:350(7):664-671.