Definitely a carrot will raise blood glucose as much as sugar - this is testable if you have a blood glucose meter. This is because carrots are starchy vegetables. Obviously the carrot will also contain vitamins which plain sugar doesn't. Possibly the article didn't make clear the difference between starcy and non starchy vegetables. The starchy veggies are things like carrots, parsnips, potatoes (Dr Richard Berstein, a Type 1 diabetic and diabetologist calls potatoes "balls of sugar" - they raise blood glucose very high). Non-starchy veggies are those such as kale, cabbage, collards, asparagus, broccoli - the list is quite extensive, and they contain very little carbohydrate and will not raise blood glucose much at all, practically unnoticeable. When it comes to fruit, most fruit is very high in carbohydrate and will raise blood glucose, the exception being some berries which are low in carbs. Grain foods are also high in carbohydrate and will raise blood glucose, wholewheat bread will raise blood glucose as much as white bread which often surprises people.
What the article was trying to say was that all carbohydrates are turned to glucose in the blood. It doesn't matter that the carbs come from sweet foods or from plain sugar or from savoury foods which are high in carbohydrates, the body turns them into glucose. In fact the body turns some starches into glucose right in the mouth through the action of the digestive enzyme amylase. A simple experiment you can do which we did back when I was at school, is to get a plain cracker, or water biscuit or matzos, they all are only made from wheat and water with maybe a bit of salt or not if you get salt free. Chew some of it and hold it in your mouth, don't swallow. After a very short time you will taste some sweetness - this is the sugars released from the wheat by the action of amylase.
