Vitamin C found to improve blood sugar and blood pressure control in people with Type 2 diabetes

 Vitamin C is well-known as a powerful antioxidant and immune-boosting vitamin, but that’s not all there is to it. A recent study shows that vitamin C is also important for maintaining good cardiovascular and metabolic health. According to researchers from Australia and the Netherlands, this essential nutrient can help lower blood pressure and improve blood sugar control in people with Type 2 diabetes.

How high blood sugar endangers your heart

Hyperglycemia, or high blood sugar levels, is a serious condition associated with Type 1 and Type 2 diabetes. People with Type 1 diabetes usually have problems producing insulin, the hormone that signals cells to take up glucose from the blood. This results in elevated blood sugar levels which, if left untreated, can lead to complications affecting the eyes, nerves, kidneys and heart. In contrast to Type 1 diabetics, hyperglycemia in people with Type 2 diabetes is caused by a decreased sensitivity of cells to insulin.

Hyperglycemia can cause high blood pressure, or hypertension, in various ways. According to an article published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology, acute hyperglycemia increases oxidative stress, which reduces nitric oxide (NO) levels. NO is a known vasodilator — a chemical that relaxes your blood vessels — produced by nearly all cells in the human body. This lack of NO negatively affects your blood vessels’ ability to dilate, resulting in high blood pressure.

Another way hyperglycemia triggers hypertension is by impairing kidney function. One of the main functions of your kidneys is to control the volume of fluids inside your body. But having high amounts of sugar in your blood is damaging to your kidneys, especially the tiny filtering units present in them. Damaged kidneys can’t get rid of excess fluid efficiently; the extra fluid you retain in your body can raise your blood pressure and force your heart to work harder. According to experts, having diabetes and hypertension greatly increases your risk of heart disease.

Improving heart and metabolic health for diabetics

In their report, which appeared in the journal Diabetes, Obesity and Metabolism, the Dutch-Australian team investigated whether supplementing with vitamin C can improve the postprandial (after-meal) glucose responses of Type 2 diabetics. They recruited a total of 31 participants for their experiment and asked them to take either vitamin C supplements or a placebo every day for four months. The participants wore glucose monitors for 48 hours and ate standardized meals before and after supplementation.

Throughout the study, the researchers measured various parameters, including how long the participants remained in a hyper- and hypoglycemic state within a day, their average 24-hour and daily postprandial glucose levels, insulin levels, blood pressure and oxidative stress levels. Results revealed that those who took vitamin C supplements daily spent almost three hours less per day in a hyperglycemic state. This means that vitamin C somehow helped improve their blood sugar control compared to those who took a placebo.

“We found that participants had a significant 36 [percent] drop in blood sugar spike after meals. This also meant that they spent almost three hours less per day living in a state of hyperglycemia. This is extremely positive news as hyperglycemia is a risk factor for cardiovascular disease in people living with Type 2 diabetes,” said Professor Glenn Wadley, the study’s senior author.

In addition to this, the researchers found that participants who supplemented with vitamin C enjoyed significant reductions in their 24-hour glucose and daily postprandial glucose levels, oxidative stress marker levels and blood pressure. According to Wadley, Type 2 diabetics have high levels of free radicals, which trigger oxidative stress and contribute to a number of diabetes’s common comorbidities, including hypertension. But thanks to vitamin C’s potent antioxidant properties, it can neutralize free radicals and prevent these complications.

Altogether the study’s findings support the use of vitamin C as an adjunct therapy to improve the blood sugar and blood pressure control of Type 2 diabetics.

“For people living with Type 2 diabetes, vitamin C could be a potentially cheap, convenient and effective additional therapy, used in addition to their usual anti-diabetic treatments,” said Wadley.