sugars and health
Yes, cane sugar in the form of sucrose has unfortunately gotten a bit of a bad rap when it comes to diabetes.
This may be surprising, but the truth is that sucrose is a more complex sugar than, say, glucose or fructose. Sucrose is made up of glucose and fructose firmly bonded to each other. It takes time for sucrose to be broken up into separate glucose and fructose molecules in the gut. The net result is a slower blood sugar spike from sucrose than with a monomer sugar like glucose.
Why is this important? Well, the worst culprit in sudden spikes in blood sugar comes not from sucrose, but from refined carbs like starch, as found in potatoes, white rice, and white bread. This refined starch is simply a chain of glucose molecules. The break down of this starch actually starts in the mouth, where the amylase contained in saliva begins to break it down into individual glucose units. This amylase cannot break down sucrose. Thus a certain weight of refined starch will spike blood sugar faster than the same weight of sucrose. These rapid blood sugar spikes are said to be more damaging than slower rises, perhaps because the carb starch causes a higher, if more fleeting, peak.
Which is not to say that sucrose still isn't a great food. It has no fiber, no minerals (unless unrefined) and no vitamins. It is the definition of empty calories. For a diabetic, it will still boost blood sugar, just not as quick or high as, say, a bowl of white rice.
Now high fructose corn syrup is another matter, but not one I'm prepared to discuss at this time from a chemistry perspective, other than to say that epidemiological studies seem to show that it's less healthy than sucrose.
Finally, the key here is moderation. A half cup of white rice with a balanced meal including vegetables and protein isn't going to kill anyone. Although brown rice, by virtue of its fiber, will result in less of a BS spike and is a better choice. Similarly, hard pasta cooked al dente will not be broken down into glucose as quickly as that white rice or baked potato.
As with most in life, proportion and balance is best.
As a type 2 diabetic myself, I know from personal experience the difference between sucrose and refined carbs. Sometimes I get low blood sugar. I can feel it, and measure it, and it's not pleasant. I have found that drinking a soft drink - with sucrose or HFCS, does not bring relief as quickly as a glucose tablet or a simple carb like a cracker or white bread/rice (glucose tabs are easiest to carry and keep). The soft drink will work, eventually, but will take a bit longer.