Among the many types of berries, raspberries are especially popular not only due to their excellent taste, but also their undoubted benefits. And given its low glycemic index, raspberry for diabetes is very suitable for a diet aimed at stabilizing blood sugar levels.
Recent statistics show that 30.3 million people, or 9.3% of the US population, have diabetes. In addition, 347 million people in the world currently have diabetes, and are projected to be the seventh leading cause of death by 2030. 
The nutrient profile of red raspberries and their polyphenolic components (i.e., anthocyanins and ellagitanins / metabolites) makes them candidates for regular inclusion in diets aimed at reducing the risk of diabetes. 
The benefits and harms of raspberries in diabetes
It is not in vain that ordinary red raspberries (Rubus idaeus) are considered a rather watery berry, since in 100 g of fresh berries the water content reaches almost 86 g, and the amount of fiber is 6.5 g. It is clear that the calorie content is low: per 100 g - 52 kcal, which is five times lower than that amount of white bread, and one and a half times less than boiled potatoes.
Most of these berries contain potassium (152 mg / 100 g), followed by phosphorus (29 mg), calcium (25 mg) and magnesium (22 mg). The iron content in 100 g does not exceed 0.7 mg; almost as much manganese and slightly less zinc. There is copper (0.09 mg / 100g) and selenium (0.2 μg / 100g). Among the vitamins in the first places, ascorbic acid (26.2 g / 100 g) and vitamin B4 or choline (12.3 mg / 100 g). If vitamin C protects pancreatic cells from oxidative stress, then vitamin B4 not only takes part in the metabolism of carbohydrates, but also improves the condition of pancreatic β-cells producing insulin. 
Vitamins such as alpha-tocopherol, niacin, pantothenic and folic acids, pyridoxine, thiamine, riboflavin, carotene (provitamin A) and vitamin K are also available.
But in order to have a positive answer to the question whether raspberries can be eaten in diabetes mellitus, to be as reasonable as possible and not cause doubt, the amount of sugar should be indicated.
When nutritionists recommend raspberries as a healthy food for patients with type 1 and type 2 diabetes mellitus and with gestational diabetes , they are guided by the fact that the glycemic index of this berry is low (25) and that only 4.4 g of sugars are contained in 100 g of berries. At the same time, 53% (2.34 g) is accounted for by fructose, in which insulin is not involved; 42% (1.86 g) is glucose (dextrose) and the rest is sucrose.
For comparison: in the same amount of strawberries or watermelon, sugar is about 6 g (in this case, 72% in the form of fructose in watermelon and 42% in strawberries); peach - 8.6 g (fructose 65%); apricot - 9.3 g (7.6% fructose); orange - 9.4 g (27% fructose); blueberries - 7.3 g (49% fructose); dark grapes - 18.1 g (42%).
Obviously, these data allow us to give the correct answer to the question, does raspberry raise sugar? Compared to other carbohydrate products, raspberries are much less likely to cause an increase in blood sugar. Moreover, studies have shown that consuming these berries in patients with type 2 diabetes helps lower blood glycated hemoglobin (HbA1c) and improves insulin sensitivity. As suggested, this is the result of exposure to raspberry flavone derivatives - anthocyanins (in particular, cyanidine), which are also found in blueberries, blackberries, strawberries, cherries and dark grapes.
And now a little about other biologically active components that determine the benefits of raspberries in diabetes. The presence of plant polyphenols, tannins, derivatives of hydroxybenzoic and hydroxycinnamic acids and other compounds is valuable in its composition. Red raspberries have a unique polyphenolic profile, which is characterized primarily by the content of anthocyanins and ellagitannins. Anthocyanins are flavonoid compounds and have a basic skeleton C6-C3-C6. They are responsible for the bright red color of red raspberries. Cyanidin-3-sophoroside, cyanidin-3, 5-diglucoside, cyanidin-3- (2 G -glucosylrutinoside), cyanidin-3-glucoside, cyanidin-3-rutinoside, pelargonidin-3-sophoroside, pelargonidin-3- (2 G β-glucosylrutinoside), pelargonidin-3-glucoside and pelargonidin-3-rutinoside are the main anthocyanins in red raspberry. 
Thus, a study of the potential therapeutic possibilities of the phytoestrogen antioxidant genistein (4,5,7-trihydroxyisoflavone), which is also present in raspberries, revealed the ability of this compound not only to reduce the formation of fat cells, but also inhibit the transfer of glucose into them by membrane transporters (GLUT). The experiments also demonstrated the positive effect of genistein on the state of pancreatic β-cells, which helps to reduce hyperglycemia.
The proposed mechanism for reducing postprandial glucose is to limit glucose uptake by inhibiting the activity of α-amylase and α-glucosidase. Compared to other berry extracts, red raspberry extracts were most effective in inhibiting α-amylase. 
Another phenolic antioxidant is in raspberries, and it is resveratrol (everyone knows that it is abundant in dark grapes), which has shown not only its anti-inflammatory activity, but also the ability to reduce fasting blood sugar and glycated hemoglobin in diabetes 2 type.
Finally, raspberries contain tyliroside - a glycoside flavonoid, which, according to preliminary studies, can help obese diabetics by increasing the activity of the adiponectin fat hormone hormone and normalizing blood glucose, insulin and lipids.
Studies in diabetic animal models confirm in vitro data that showed that a 5-week intake of cyanidin-3-glucoside (0.2% of the diet) reduced fasting glucose and improved insulin sensitivity, measured with insulin or glucose. Tolerance test compared to control groups. Effects on metabolic parameters were accompanied by a decrease in the expression of inflammatory cytokine genes in white adipose tissue and an increased level of glucose regulator 4, but not adiponectin. 
Studies show that the components of red raspberries have biological activity, which may have clinical significance for the prevention or treatment of diabetes. In vitro and animal studies in vivo have demonstrated antioxidant, anti-inflammatory and sensitizing effects on insulin in tissues, especially in adipose tissue. These effects have led to a decrease in glycemia and glycated proteins.  Increased insulin secretion by pancreatic β-cells is another important mechanism for controlling glucose levels and slowing the progression of the disease.
Damage to raspberries in diabetes can be in the presence of an allergy or a violation of the metabolism of uric acid - with the deposition of its salts (urates) near the joints and gout.
It is not recommended to eat raspberries in chronic renal failure, as well as during periods of exacerbation of inflammatory diseases of the stomach and in patients with aspirin bronchial asthma (since the berries contain salicylic acid - 5 mg / 100 g).
Experts warn that raspberries containing substances of the phytoetrogen class are contraindicated in case of endometriosis or uterine myoma, as well as in oncological diseases of hormone-sensitive organs: mammary glands, uterus, ovaries.
About which berries are useful for diabetes mellitus type 1, 2, more details in the publication - Berries for diabetes mellitus type 1 and 2: which ones can and should not be consumed?
If you do not know how to replace raspberries with diabetes, read:
Raspberry Leaves for Diabetes
The leaves of Rubus idaeus have been used universally as a remedy for centuries: for colds and fever, heart problems and high blood pressure, intestinal upsets, anemia, menorrhagia, morning sickness during pregnancy, and to alleviate childbirth and reduce postpartum hemorrhage.
Raspberry leaves contain tannins (derivatives of ellagic acid) and flavonoids. The amount of which is higher than in berries. Also included are organic carboxylic, phenolic and hydroxybenzoic acids; terpenoids, glycosides, etc.
Raspberry leaf belongs to pharmacopoeial plants, studies have proven ego safety, and many endocrinologists advise their patients to use raspberry leaves for type 2 diabetes and gestational diabetes - to reduce hypoglycemia and insulin resistance - in the form of herbal decoction, infusion or tea.