Postprandial – Diabetes Under Control

The prevalence of type 2 diabetes throughout the world has reached epidemic proportions. Traditional risk factors can no longer completely explain the risk of developing cardiovascular disease in those with diabetes. Several studies have successfully indicated postprandial metabolic derangements such as hyperglycaemia as well as hypertriglyceridaemia, which are highly exaggerated and immensely prolonged in type 2 diabetes, are key risk factors for cardiovascular disease and heart complications because they eventually lead to oxidative stress as well as endothelial dysfunction. Here, we will look at current evidence that shows that when postprandial blood sugar normal range is not maintained, there is a major risk factor for developing cardiovascular disease. Moreover, we throw light on the mechanisms that underlie this association.

PPS and Cardiovascular Disease

It is quite well recognized that those with type 2 diabetes are at an increased risk of developing atherosclerosis, which can lead to high cardiovascular disease morbidity as well as mortality. Hence, with the rise in the overall prevalence of diabetes, it is inevitable that the global burden of cardiovascular disease will increase, too. Because the so-called traditional risk factors such as hypertension, high cholesterol, smoking, and low levels of high-density lipoprotein (HDL) cholesterol cannot completely explain the excessive risk of developing cardiovascular disease in diabetic patients, there is a need to identify other risk factors.

Atherosclerosis

Two key processes that are involved in the development of atherosclerosis (which is the underlying cause when it comes to cardiovascular disease) are inflammation and activation of coagulation. Though the precise mechanisms that underlie atherogenesis are still not entirely understood, it is believed that vascular endothelial dysfunction is the starting point.

That said, only in recent times, the excessive as well as prolonged metabolic disturbances that occur in the postprandial blood sugar levels in those with type 2 diabetes have rekindled interest as potential risk factors for cardiovascular disease and heart complications.

Over the last 200 years, a significant body of evidence has accumulated that indicates a relation between postprandial dysmetabolism and the risk of developing cardiovascular disease.

Postprandial Hyperglycaemia

Several mechanisms help in keeping plasma glucose levels in healthy individuals between stringent limits, even after an intake of a high-carbohydrate meal. Dysfunction of beta-cells (for instance, disruption of the normal insulin secretion pattern) and insulin resistance lead to glucose intolerance, and both can be found fairly early in the disease process that eventually leads to type 2 diabetes.

Numerous epidemiological studies have demonstrated an association between two-hour glucose concentrations post consumption of a 75-gram glucose load (2hPG) and the development of cardiovascular disease among the general population.

A meta-analysis of twenty studies involving 95,000 individuals indicated a continual relationship between post-load glucose levels and cardiovascular-disease risk that extends into the non-diabetic range.

Another study indicated that 2hPG concentrations, even in those individuals with normal fasting glucose, were also associated with mortality, regardless of fasting plasma glucose concentrations.

Chronic hyperglycaemia has been successfully associated with impaired endothelial function. Some researchers have shown that high levels of postprandial blood glucose are accompanied by numerous alterations in the system of coagulation.

Thus, post-load or postprandial blood sugar levels have an association with an enhanced risk of cardiovascular disease. That said, a majority of epidemiological studies that addressed the contribution of post-load glucose levels to the risk of developing of cardiovascular disease failed to consider the earlier-mentioned classical risk factors, including dyslipidaemia.

These data successfully indicate that post-load glucose may not be an independent risk factor for cardiovascular disease but rather a risk-marker, which is suggestive of other underlying metabolic disturbances, including insulin resistance and dyslipidaemia, which could have an even-greater impact on the risk for cardiovascular disease.

To conclude, direct evidence of postprandial hyperglycaemia serving as an independent risk factor is not convincing. Hence, the observed association between post-load glucose excursions with cardiovascular disease can be partly explained by the presence of related cardiovascular-disease risk factors as well as insulin resistance.

Postprandial Hypertriglyceridaemia

In a typical western diet, around 40% of the energy intake is comprised of fats. When it comes to the insulin-resistant state, the eventual production of very low-density lipoprotein (VLDL) by the liver is extremely high. In combination with a reduced lipoprotein lipase activity, this results in high concentrations of triglycerides, particularly in the postprandial state.

In the year 1959, an association was reported between plasma concentrations and incident coronary heart disease. That said, the known inverse association between HDL cholesterol and triglycerides makes it challenging to demonstrate an independent association between atherosclerotic vascular disease and plasma triglyceride.

A recently concluded meta-analysis that included data of 57,000 subjects from as many as 17 studies showed that fasting triglyceride concentrations were essentially an independent risk factor for cardiovascular disease, additionally when adjusted for HDL cholesterol.

When it comes to general practice, serum lipid concentrations that include triglycerides are typically measured in the morning, after observing an overnight fast. That said, the fasting value must be considered the nadir of the 24-hour triglyceride profile and therefore could be misleadingly low.

Few years ago, numerous clinical studies have demonstrated that high postprandial triglyceride-rich lipoproteins (TRL) could be related to coronary heart disease and/or carotid artery disease in both diabetic and non-diabetic individuals.

To Sum It Up:

Historically, when it comes to diabetic individuals, primary focus was laid on hyperglycaemia; however, recent studies demonstrate the role of dyslipidaemia (especially hypertriglyceridaemia) as a risk factor for cardiovascular disease. Although presently epidemiological as well as long-term intervention studies are lacking, in vivo data convincingly demonstrates an association between postprandial TRL and indicators of cardiovascular disease. Hence, it could be stated that prolonged postprandial hypertriglyceridaemia causes an atherogenic environment in vivo. However, when it comes to postprandial hyperglycaemia, the evidence of postprandial hypertriglyceridaemia as independent in cardiovascular disease is still lacking.

References:

https://pmj.bmj.com/content/81/951/1

Let us face the truth: the present, modern-day diet is highly processed, nutrient-depleted, and calorie-dense. Consuming such a diet leads to PPS (Post Prandial Sugar) spikes in blood glucose as well as lipids. This state is also known as post-prandial dysmetabolism.

To be specific, a diet that is rich in minimally processed, high-fibre, plant-based foods (including fruits and vegetables), whole grains, nuts, and legumes, will surely blunt the spike in postprandial blood sugar levels.

Moreover, lean protein, fish oil, vinegar, cinnamon, and tea have a positive impact on postprandial dysmetabolism.

The Best Diets

The traditional Mediterranean, as well as Okinawan diets, are comprised of minimally processed natural foods that are low in calorific value but high in nutrient density. These diets are much closer to our ancestral hunter-gatherer eating habits, for which present-day humans are genetically adapted.

To be precise, diets that are comprised of prodigious amounts of fresh, unprocessed plants with a moderate level of lean protein and healthy fats (such as Omega-3 and monounsaturated fatty acids), an extremely low level of processed carbs as well as saturated and trans fats, and foods that have a content of antioxidants are known to drastically improve postprandial blood glucose levels.

Type and Amount of Carbs

The amount, as well as the type of carbs consumed in a meal, is a predominant determinant of PPS levels. A meal such as a loaf of white bread and jelly (with a glycaemic index of 80) will eventually result in a two-fold incremental increase in blood glucose levels in comparison with an isocaloric meal comprising of whole-grain bread and peanut butter (with a glycaemic index of 40).

Ideal carbs for improvement in postprandial dysmetabolism include fruits (such as cherries and grapefruits) and green leafy vegetables (such as spinach and broccoli). These foods are low in calorific value and glycaemic index but high in fibre and water content.

Deeply pigmented plant-based foods as well as drinks such as dark chocolate, tea, red wine, berries, and pomegranates help in protecting the vascular endothelium from postprandial oxidant stress.

Restricted consumption of refined carbs is known to improve postprandial blood sugar levels, with an additional benefit of reduction of intra-abdominal fat, which is predominantly seen in those with insulin resistance.

When it comes to postprandial blood sugar spikes, the total amount of carbs consumed is as important as the glycaemic index (GI). Smaller portions of high GI foods such as potatoes and rice will eventually have a proportionally smaller effect on PPS levels in comparison with larger portions of the same foods. In contrast, low GI foods such as legumes (lentils) can cause significant postprandial glucose spikes when consumed in enormous quantities. Hence, the portion size of any food is critical.

Olive Oil, Fish Oil, and Nuts

Nuts are known to substantially reduce postprandial glucose excursion by slowing the process of digestion. Recent studies demonstrate that almonds, peanuts, or pistachios, when consumed in tandem with high GI carbs (such as mashed potatoes or white bread) will surely reduce blood glucose levels by nearly 30-50%.

Replacement of refined carbs with monounsaturated fats (found in olive oil and nuts) is a surefire way to successfully reduce postprandial hyperglycaemia.

Fish oil (which contains Omega-3 fatty acids) lowers postprandial triglyceride levels by as much as 16-40% in a dose-dependent manner.

Vinegar & Olive Oil

A concoction of vinegar and olive oil is the go-to salad dressing when it comes to the Mediterranean diet. Consuming vinegar with meals was widely used as a home remedy for diabetes before the emergence of pharmacologic glucose-lowering therapy.

Recent studies have indicated that vinegar substantially reduces post-meal glycaemia, perhaps because acetic acid slows down the process of gastric emptying, thus delaying carbohydrate absorption and improving satiety.

Some studies have proven that consumption of 1-2 tablespoons of vinegar, when consumed along with high GI foods such as white rice or white bread has two benefits: (1) lowering of postprandial glucose by 25-35% and (2) increasing post-meal satiety by much more than twofold.

High-Biological-Quality Protein

Protein is a vital component of an anti-inflammatory and cardioprotective diet. That said, the traditionally favoured sources of protein in the modern diet are found in foods that are high in calories and saturated fats (such as ground beef, bacon, sausage, and cheese), which can worsen postprandial dysmetabolism.

In sharp contrast, lean protein consisting of high biological value will help in both reducing post-meal glucose excursion and improving satiety.

It can be inferred from some studies that protein comprising of high biological value in the form of egg whites, game meat, lean red meats, fish, skinless poultry breast meat, as well as whey protein when consumed with regular meals will reduce postprandial inflammation and eventually help in preventing obesity.

To Sum It Up:

Modern diets are calorie dense but nutritionally deficient. Regular consumption of such a diet in combination with living a sedentary lifestyle can cause obesity, coronary artery disease, and diabetes, besides other complications. When it comes to diabetes, individuals find it challenging to maintain a postprandial blood sugar normal range. The key lies in minimising the intake of processed foods and opting for plant-based foods such as fresh fruits and green leafy vegetables, along with immense amounts of nuts, seeds, and high-biological-protein.

Disclaimer: The information mentioned in this blog is for general awareness only. It is not intended to be taken as a substitute for medical advice. Before making any dietary changes or for any health advice, please consult a medical professional.

References:

https://www.sciencedirect.com/science/article/pii/S0735109707034444