According to the latest report from the Centers for Disease Control and Prevention (CDC), more than 29 million people within the US (approximately 9.3% of the population) have diabetes. This includes 21 million people who have been diagnosed with the disease, but another eight million — nearly 28% of those with diabetes — have not been diagnosed. Globally, diabetes affects more than 100 million people.
The physical and financial impact of the disease is staggering: Just a few of the major health consequences of diabetes are kidney failure, lower limb amputations, and blindness among adults. The American Diabetes Assn. has estimated that the total health care cost of diagnosed diabetes is around $250 billion.
- Diabetes and Metabolism
- Inflammation and Obesity
- Nutrition Intervention
- General Dietary Approaches
- Food Componenets
- Probiotic Intervention
Of this, almost $200 billion comprises direct medical costs, with the remaining $50 billion accounted for through decreased productivity. Decreased productivity includes costs associated with people being absent from work, being underproductive while at work, or not being able to work at all because of diabetes.
Diabetes represents a spectrum of critical conditions in which a vital organ known as the pancreas does not produce sufficient insulin or in which the body does not properly respond to insulin produced. Thus, the blood sugar is elevated over prolonged periods of time.
There are several different types of diabetes. The most common forms are type 1, type 2, prediabetes, and gestational diabetes. All impact serum glucose levels and, if left untreated, can cause many complications.
Type 1 diabetes, formerly termed juvenile diabetes, is a condition in which an individual’s immune system attacks the pancreas, specifically destroying the insulin-releasing beta cells. This autoimmune process can occur at any age. It is most commonly diagnosed from infancy to the late 30s. Those diagnosed with type 1 diabetes must inject insulin several times every day or continually infuse insulin through a pump, in addition to managing their dietary patterns and physical activities. It is estimated that about 5-10% of Americans who are diagnosed with diabetes have type 1.
Type 2 diabetes, previously known as adult-onset diabetes, is the most common form of diabetes. It usually develops after age 40. However, recent reports suggest an increasing frequency in the diagnosis of type 2 diabetes among children. It is estimated that 90-95% of Americans diagnosed with diabetes have type 2.
“Insulin resistance” describes a condition in which the pancreas produces insulin, yet the body is unable to use it effectively. This condition has been associated with elevated levels of free fatty acids and pro-inflammatory substances in plasma, decreased glucose transport into muscle cells, and elevated glucose production in the liver.
Insulin resistance also is known as “Metabolic Syndrome” and “Syndrome X.” Insulin resistance is considered a form of prediabetes, a condition that occurs when serum glucose levels are higher than normal but not high enough for a diagnosis of type 2 diabetes. More than 40 million Americans are believed to have prediabetes.
Type 2 diabetes develops among those who cannot increase insulin secretion sufficiently to compensate for their insulin resistance. Thus, the insulin concentration in blood can be relatively high, yet too low to compensate for the level of glucose in the blood. Adding to the complexity of type 2 diabetes is the presence of excess glucagon.
Glucagon is a hormone produced by the alpha cells within the pancreas. Its purpose is to stimulate the liver to convert glycogen (a natural polysaccharide storage form of glucose energy in all mammals) into glucose. In type 2 diabetes, the reciprocal relationship between the glucagon-secreting alpha cells and the insulin-secreting beta cells is lost. The result is an excess of glucagon in the blood and subsequent elevation of blood glucose.
Diabetes and Metabolism
Because diabetes is a disease of impaired glucose metabolism, and glucose is a fundamental unit of carbohydrates, the importance of foods and beverages in managing the disease cannot be understated. Unchecked, diabetes wreaks havoc on the entire body. But even well-controlled diabetes still carries higher risks for morbid conditions.
Metabolic consequences known to occur in diabetes go far beyond elevated blood sugar. They include excess free fatty acids in the blood, altered functional properties of endothelial cells inside arteries and veins, and other impairments. And, as has recently been recognized, systemic inflammation is strongly correlated with diabetes.
Diabetes is linked to multiple diseases and conditions, including those that affect the eyes, kidneys, nerves, and circulatory system. For example, one disease condition causes abnormal growth of blood vessels in the retina, another damages the filtering functions of the kidneys, and yet another causes sensory nerve damage, particularly in the feet.
In addition, cardiovascular physicians manage many diabetic patients because vascular diseases are the principal causes of death and disability among these patients. These physicians often observe individuals with atherosclerosis as well as eye and kidney diseases. These latter conditions are major causes of blindness and end-stage renal failure.
Importantly, these alterations reflect changes in the synthesis or degradation of nitric oxide (NO). NO is a key molecule synthesized by the endothelial cells that line blood vessels. Decreased levels and bioavailability of NO underlie the vascular consequences observed among those with diabetes. This is because NO protects blood vessels from atherosclerosis through unique cell signaling, which in turn reduces platelet and leukocyte interaction with the vascular wall, thereby inhibiting vascular smooth-muscle cell proliferation and migration.
The loss of endothelium-derived NO permits increased activity of pro-inflammatory factors that result in expression of substances that reduce the flexibility and function of blood vessels. This leads to persistent inflammation and, ultimately, damage to those blood vessels.
Inflammation and Obesity
There is considerable interest in immunity and inflammation. The process of inflammation is complex and multifactorial, especially as it relates to diabetes. For example, inflammation is associated with any insult to the body; yet, inflammation is also a healing process. Diabetes is such a complex disorder that one needs to address the myriad of aforementioned co-morbidities.
That there is some connection between obesity and diabetes is undeniable—about nine in 10 persons with type 2 diabetes are overweight or obese. In recent years, some studies have raised the question as to whether altered blood sugar management might lead to obesity rather than the other way around. The relationship between inflammation and obesity also is generating increased study of this “chicken or the egg” nature.
Many foods have been presented as anti-inflammatory agents in recent years. Some evidence suggests daily chocolate consumption (i.e., 20g per day of dark chocolate, rich in polyphenols) could enhance insulin sensitivity and reduce blood pressure. Other studies have singled out similar polyphenolic compounds in dark berries, such as black currants and blueberries, that have shown anti-inflammatory effects as well.
Other food ingredients studied for reduction of inflammatory markers range from omega 3 fatty acids to polyphenolic and antioxidant compounds from a number of plants. Ginger, cinnamon, and turmeric are among the many botanical compounds exhibiting some anti-inflammatory properties.
While all such ingredients are easily incorporated into food and beverage products, formulators should exercise caution before promoting any ingredient for specific effects or interpreting the magnitude of results for persons with diabetes. It also should be noted that the inflammatory environment secondary to the increased adiposity and serum glucose of diabetes can create a situation in which the application of foods or supplements rich in phenolic compounds might not be as effective as expected.
This is due to alteration of their bioavailability. Thus, it is suggested that dietary interventions making use of these phenolic compounds likely will have to be adjusted to accommodate for altered bioavailability. Such adjustments should include modifying formulations to include specific proportions of macronutrients such as protein and carbohydrates, along with specific micronutrients such as ascorbic acid, which have been found to increase the bioavailability of phenolic compounds.
The American Diabetes Assn. recommends a diet for diabetes that includes carbohydrates from fruits, vegetables, whole grains, legumes, and low-fat milk is encouraged for good health. Monitoring carbohydrates—whether by carbohydrate counting, exchanges, or experienced-based estimation—remains a key strategy in achieving glycemic or blood sugar control.
For product developers, this means that for successful crafting and marketing of products tied into blood sugar management, more comprehensive labeling might be best. This might involve not only focusing on specific functional ingredients the products contain, but also giving greater consideration to portion size, as well as more detailed nutrient information regarding carbohydrate, protein, and lipid content.
For example, when it comes to protein, there is insufficient evidence to suggest that usual protein intake (15–20% of energy) should be modified for individuals with diabetes and normal kidney function. Still, ingested protein can increase insulin response without increasing plasma glucose concentrations. For individuals with type 2 diabetes, protein could exacerbate nocturnal hypoglycemia (drop in blood sugar).
High-protein diets are not recommended, especially as a method for weight loss for persons with type 2 diabetes. The long-term effects of protein intake above 20% of calories on management of diabetes and its complications are unknown. Although such diets might produce short-term weight loss and improved blood sugar management, it has not been established that these benefits are maintained long term, and long-term effects on kidney function in persons with diabetes are unknown.
There is no clear evidence of benefit from vitamin or mineral supplementation among persons with diabetes (compared with the general population), provided they do not have underlying nutrient deficiencies. Some studies have indicated a role for iron in blood glucose management, and chromium has been promoted as an ingredient that can help reduce blood sugar levels. However, while often promoted for such benefit, chromium supplementation by itself has not stood up to well-controlled studies in humans.
General Dietary Approaches
When it comes to basic dietary recommendations for diabetes, modest restriction of saturated fats and simple sugars is reasonable. There also are emerging recommendations that delve into more specifics.
Weight management figures largely in obesity-related diabetes, of course. But modest weight loss (5-10% of total body weight) has been associated with significant improvements in cardiovascular disease risk factors in patients with type 2 diabetes. Risk factor reduction was even greater in patients who lost 10-15% of their body weight.
Interestingly, some research has indicated more significant benefit from a low-carbohydrate, Mediterranean-style diet than from a low-fat diet in patients with newly diagnosed type 2 diabetes. In one good-sized, single-center, randomized trial of 215 overweight patients with newly diagnosed type 2 diabetes conducted by Katherine Esposito, MD, PhD, et alia, subjects were assigned to either a Mediterranean-style diet (< 50% of daily calories from carbohydrates) or a low-fat diet (< 30% of daily calories from fat).
After four years, the participants (who had never been treated with antihyperglycemic drugs and whose HbA1c levels were below 11%) assigned to the Mediterranean-style diet had lost more weight and had demonstrated more improvement in some measures of glycemic control and coronary risk than had participants consuming the low-fat diet. In fact, only 44% of patients in the Mediterranean-style diet group required antihyperglycemic drug therapy, compared with 70% of those in the low-fat diet group.
Over the past several years, the general public has been enamored with plant-based diets. The rise of veganism, vegetarianism, and flexitarianism (flexible vegetarianism) can pose numerous nutritional challenges, as well as personal health opportunities. Thus, it is not surprising that many plant-derived substances can be valuable in reducing the risk of several potential dietary pattern-related health conditions, including diabetes.
Soy isoflavones, including daidzein and genistein, are well-known as beneficial phytochemicals. A 2011 study of isoflavone aglycones (a form of plant-derived substance without a carbohydrate component), found that when pasta was enriched with this bioactive compound, it was able to improve endothelial function in patients with type 2 diabetes and favorably affect cardiovascular disease risk markers.
Dietary fiber represents a classification of complex carbohydrates that have strong backing for management of such metabolic aspects as satiety, weight management, glucose metabolism, and blood sugar control. Non-digestible soluble and insoluble carbohydrates are primarily derived from plant sources, such as fruit, vegetables, legumes and grains. Common forms of carbohydrate accepted as dietary fiber include lignin, chitin (from fungi), pectin, beta-glucan, resistant starch, inulin, oligosaccharides, and a variety of gums. Each of these has unique structural characteristics and biological functions.
A regimen of supplemental soluble fibers, such as those purified from partially hydrolyzed guar gum (PHGG) and inulin (derived mainly from artichokes and chicory root as well as nominal amounts from asparagus, leek, onions, and banana) have been associated with clinically significant reduced post-prandial glucose levels, lower LDL, reduced C-reactive protein (a non-specific marker of inflammation), and lower body mass index (BMI).
One key area in which the use of dietary fiber and like ingredients is especially beneficial is in creating snacks for blood sugar management. For many persons with diabetes, a regimen of small meals and snacks throughout the day can be particularly helpful in keeping blood sugar levels on an even keel. But those snacks must be made with an eye toward high satiety rather than a burst of energy.
By replacing high-glycemic sugars with slow-release carbohydrates, such as isomaltulose, resistant starch, and native starches, developers can create snacks that support a healthier metabolism, simultaneously keeping satiety levels up and making weight management easier. These fibers also can be combined with low-glycemic, clean-label sweeteners, allowing the product developer to create high-satiety snacks that compete with so-called “junk” snacks for the feeling of indulgence.
Numerous such low-glycemic, low-calorie sweeteners are available. Crystalline allulose is a recent entrant into the field. A chemical relative of fructose, it is naturally sourced and has 70% of the sweetness of sucrose, while functioning similarly in formulations (including Maillard reaction browning). Another popular sweetener in this category is the oligosaccharide inulin. Inulin has a “double advantage” of combining mild sweetness with fiber functionalities.
In addition, the zero-calorie sweeteners monkfruit and stevia continue to gain in popularity for foods and beverages targeting blood sugar control as well as weight management. Monkfruit is high in antioxidants, and a number of studies have associated its use with specific anti-diabetes actions in addition to its capacity as a non-glucose, non-caloric sweetener. These include mitigation of kidney damage and improved insulin secretion.
Another major role certain fibers and starches play in mitigating the effect of diabetes is in their function as prebiotics: that is, they feed friendly probiotic bacteria. Probiotics are quickly gaining recognition as beneficial to blood sugar control. Much attention has recently been focused upon the potential interaction between dietary components, species of gut bacteria, and metabolic health-related outcomes.
Selective changes in diet and supplementation with certain probiotic species and prebiotics (fermentable fibers) have demonstrated an ability to induce favorable changes in the gut microbiome and improve glucose homeostasis.
In a systematic review and meta-analysis titled “Probiotics for the management of type 2 diabetes mellitus” and published last summer in Diabetes Research and Clinical Practice, Syamimi Samah, PhD, and colleagues at the Faculty of Pharmacy, Universiti Teknologi MARA in Selangor Darul Ehsan, Malaysia, concluded that, “A moderate hypoglycemic effect of probiotics, with a significantly lower FBG [fasting blood glucose] was noted.”
Another 2016 meta-analysis, “Effect of probiotics on metabolic profiles in type 2 diabetes mellitus,” was conducted by Caifeng Li, PhD, and colleagues at Tianjin Medical University in Tianjin, China. It also supported the ability of probiotics to reduce fasting blood glucose levels in persons with diabetes.
With so many new opportunities for product developers to choose from, creating foods and beverages designed for diabetes is entering a new era. While weight management remains one of the primary aspects of nutrition intervention for diabetes, the pathways to finer control of blood sugar through diet are especially promising. Ingredients and ingredient systems that go beyond simply being low calorie or sugar free make diabetes management through diet a less onerous—and more tasty—proposition.
Originally appeared in the June, 2017 issue of Prepared Foods as Developing for Diabetes.
Extensive study of dairy and its components has revealed a wealth of benefits for everything from weight control to reduction of risk for a number of disease states, including diabetes. Various factors, from satiety to healthful fat compounds, are indicated in bringing those benefits. One of those is the primary saturated fatty acid in all mammals, palmitic acid. This fatty acid has received a great deal of attention for its ability to reduce the risk of diabetes and cardiovascular disease.
Many ingredients found in dairy also have shown an ability to help with blood sugar management, but one recent study drew attention to the dairy phospholipid trans-palmitoleate. Increased intake of trans-palmitoleate has been associated with lower risk to metabolic function. The phospholipid is
principally derived from naturally occurring dairy and other ruminant trans-fats. Circulating
trans-palmitoleate in the bloodstream has been associated with lower insulin resistance, lower incidence of diabetes, and reduction of atherogenic dyslipidemia (unhealthy cholesterol levels, including elevated levels of triglycerides and low-density lipoproteins coupled with low levels of high-density lipoproteins).
New Fiber Claim
Resistant starch, a type of complex carbohydrate that behaves like a starch in formulations but like an indigestible fiber in the digestive system, recently received FDA approval for two claims referencing help against diabetes. Specifically, the claims now permitted for resistant starch are:
- “High-amylose maize resistant starch may reduce the risk of type 2 diabetes. FDA has concluded that there is limited scientific evidence for this claim.” and
- “High-amylose maize resistant starch, a type of fiber, may reduce the risk of type 2 diabetes. FDA has concluded that there is limited scientific evidence for this claim.”
In the case of these claims, the qualified health claim language “limited scientific evidence” merely refers to the fact that thus far, resistant starch has a relatively small number of studies compared to a health claim with significant scientific agreement, and that some studies showed an improvement in one marker, but not in other markers.
These claims can be used on the packaging of conventional foods, as defined by 21 CFR 101.14. Such products include bakery items, nutrition bars, cereals, and pastas, among others.
Medical Nutrition Therapy
Medical Nutrition Therapy (MNT) is an integral component of diabetes management. The goals of MNT, as advanced by the American Diabetes Assn. (ADA), apply to individuals at risk for diabetes or with pre-diabetes. The intent of these goals is to decrease the risk of diabetes and
cardiovascular disease by promoting healthful food choices that lead to sustainable moderate weight loss. Further, the ADA goals are to:
- Achieve and maintain blood glucose levels in the normal range or as close to normal as is safely possible;
- Achieve and maintain a lipid and lipoprotein profile that reduces the risk for vascular disease;
- Achieve and maintain blood pressure levels in the normal range or as close to normal as is safely possible;
- Prevent, or at least slow, the rate of development of the chronic complications of diabetes by modifying nutrient intake and lifestyle;
- Address individual nutrition needs, taking into account personal and cultural preferences and willingness to change;
- Maintain the pleasure of eating by only limiting food choices when indicated by scientific evidence.
Among the general recommendations from the ADA position statement are the following:
Individuals at high risk for type 2 diabetes should be encouraged to achieve the USDA recommendation for dietary fiber (14 g fiber/1,000 kcal) and foods containing whole grains (one half of grain intake).
There is not enough consistent information to conclude that low-glycemic load diets reduce the risk for diabetes. Nevertheless, low-glycemic index foods that are rich in fiber and other important nutrients are to be encouraged. It is important to note that the concept of glycemic index relative to foods has not been recognized by the FDA and was not supported by the Dietary Guidelines for Americans in either 2010 or 2015.
Seaweed for Diabetes
There is an increased interest in innate substances in some algae, including seaweed. Fucoidan, the name of two forms of complex polysaccharides found in species of brown algae and brown seaweed, is of special interest. A limited number of studies among animal models suggest some forms of fucoidan could reduce kidney disease associated with diabetes, and reduce elevated blood sugar in diabetes. It even has shown promise for stimulating the production and secretion of insulin from the pancreas. More study is needed, but the recent surge in seaweed-based snacks suggests an opportunity for the application of the ingredient to products targeting diabetes.