The large-scale prevalence of diabetes mellitus in the recent decades is a challenge to medical science. The data presented by Danaei G. et al stated that 347 millions of the global population were diabetics . WHO surveys (2004) on the mortality rate and selection of basic risk factors reported 3.4 millions deaths caused by maintaining permanent elevated blood glucose levels [13, 14, 31]. WHO Expert statements outlined that in 2030 diabetes, as a disease, would hold the 7th place by global mortality rate [13, 27, 31]. Numerous institutions and teams have investigated the problem for decades and have provided evidence and unified recommendations for control and management of clinical and health care for diabetics and risk population groups [2, 26, 31].
In spite of the high level of current scientific development and implementation of varied programmes, projects, approaches and other activities focused on mitigation of type 2 diabetes prevalence, yet the efforts are insufficient to manage this disease. The processes of research and of increasing prevalence seem to proceed synchronously, with similar speed.
The aim of this study is to present some relevant recent scientifically based nutritional recommendations in type 2 diabetes prevention.
The methodology involved analysis and assessment of scientific evidence reported during the last 10 years, published in the following scientific journals: Diabetes Care, Diabetology, Am J Clinical Nutrition, Eur. J Nutrition, Ann. Nutrition Metab., as well as in the WHO and American Diabetes Association (ADA) documents.
Analysis of studies referring to nutrition intervention at type 2 diabetes
The current medical science focuses on the identification of risk and preventing factors. Nutrition is outlined as one of the main alternatives among the wide range of risk factors for triggering and development of type 2 diabetes.
The symptoms of type 2 diabetes are similar to those of type 1 diabetes, though less pronounced, that causes the late diagnostics of the disease, even years after its initiation when the diabetes pathology with the characteristic complications is fully developed. Thus primary prevention is of particular importance as its effectiveness depends to a substantial extent on the dietary model.
The investigation of the historical development of the knowledge on the relationship between nutrition and diabetes showed that yet far behind in time the daily dietary intake of carbohydrates, both quantitative and qualitative composition, was the object of greatest emphasis. The recent years evidenced the involvement of newer concepts for “carbohydrate calculation” and “glycemic index”. Naturally, the total energy, energy from fats, amount of saturated fats and trans fats were also considered as associated with diabetics’ body mass control and higher cardiovascular risk [5, 8, 12, 30].
One of the main diet-related biomarkers in diabetes is the glucose blood level. The changes in glucose level, determined in a blood sample taken on an empty stomach, showing levels above the referent values and the disturbed glucose tolerance are the intermediate states at transition from normal physiology and metabolism to diabetic disease. Individuals with confirmed similar changes are regarded as persons at risk, with high probability for development of type 2 diabetes. The achievement of effective primary prevention is of greatest importance as it enables the triggering and development of the disease and the complications associated with it.
Nutrition intervention is of utmost importance in diabetes prevention, in control of existing diabetes state, and in prevention or retarding the development, and reduction of diabetes-related complications. Thus, it is important at all prevention stages. The awareness of the role of nutrition is an integral part of the knowledge on diabetes that is necessary and mandatory in order to achieve effective self-control.
Nutrition and Prevention of Type 2 Diabetes
Primary prevention – Prevention of type 2 diabetes initiation. Nutrition intervention for individuals with obesity and pre-diabetes.
Secondary prevention – prevention of development of pathophysiological processes. Involving nutrition in metabolic control of diabetes.
Tertiary prevention –prevention of aggravations. Involving nutrition in retarding diabetes-associated complications.
A number of expert commissions and institutions have provided scientifically based position statements and recommendations for dietary interventions at diabetes. This, though, is a continuously developing process as the new achievements of medical science and practice are constantly implemented in the recommendations, introducing more and more new positions. Thus, the position statement of ADA, published in 2002 was modified by its new version, published in 2004. This document updated all previous position statements. The essence of the document was based on key publications after 2000 and presented concentrated information using scoring depending on the level of scientific evidence based on the ADA range system. This fact definitely showed a strive to implement all scientifically confirmed novelties.
Special emphasis is put on nutrition at overweight and obesity as they are closely related to diabetes.
Primary prevention interventions strive for retarding or stopping the appearance and development of type 2 diabetes. This involves measures for reduction of obesity prevalence and specific dietary regimes for pre-diabetics. The reduction of diabetes risk through promotion of healthy diets leading to continuous moderate weight loss and provision of the necessary nutrients in amounts, complying with the physiological needs of the organism is a main task of primary prevention. The activities in this aspect should rather be manifested much earlier than the appearance of the disease symptoms. Very often, though, their expression is late, thus leading to more difficult risk modulation. That is why, each individual with family history has to maintain a relevant dietary regime.
Thus, through modulation of nutrition, the positions, described below, can be achieved:
— Achieving and maintenance of:
- Blood glucose levels in normal limits or as close to the limit as possible and safe.
- Lipid and lipoprotein profile that supports cardiovascular risk reduction.
- Blood pressure levels in normal limits or as close to limits as possible and safe.
— Prevention or at least retarding the diabetes-associated pathophysiological processes – through modification of nutrient intake and life style.
— Compliance with the individual dietary requirements – through personal and cultural preferences.
— Maintaining the feeling of enjoying the diet – with restriction of only those preferences that have been scientifically identified as health risk.
Individuals with initial diabetes or pre-diabetics should practice individualized dietetic nutrition that could be achieved by good knowledge on the composition of foods, given selectively, depending on the disease stage. The dietary advice could be effective if the specific needs of the particular individual were considered.
Clinical tests on diabetics after nutritional intervention reported reduced HbA1c (A1C) with 1 – 2% for type 2 diabetes. A metaanalysis of tests on non-diabetic humans, with free life style as well as the discussions of expert commissions report that adequate nutrition reduces LDL cholesterol with 15–25 mg/dl. After the start of a provisional precisely tuned diet, improved indicators can be observed only after 3 – 6 months. The metaanalysis and the decisions of various expert commissions focus the attention on nutrition, as well as on the role of life style that complement each other [1, 3, 18, 32].
Energy balance, overweight and obesity are important factors for the development of type 2 diabetes, directly associated with nutrition. In insulin-resistant obese or overweight individuals it is outlined that moderate weight loss improves insulin resistance. Thus, weight loss is recommended to all of those individuals that are either diabetics or at diabetes risk [8,16,23,25,29]. For quick weight reduction (within 1 year) low-carbohydrate or low-fat diets could be effective. The lipid profiles, renal function and protein intake (in case of nephropathy) of patients on a low-carbohydrate diet must be monitored and the glycemic therapy should be regulated when necessary.
It is exclusively important to control the body weight in order to reduce diabetes-related risks. The control is implemented by the following evaluation indicators: overweight – BMI ³ 25kg/m2 and obesity BMI ³ 30 kg/m2. The risk for concomitant diseases associated with excessive adipose tissue raises with the increase of BMI in the above quoted and in broader limits. It must be acknowledged that in certain Asian populations the prevalence of people at high risk for type 2 diabetes and cardiovascular diseases (CVD) is significant even at BMI ³ 23 kg/m2. The visceral abdominal fat measured as waist circumference ³ 35 inches for women and ³40 inches for men is used in combination with BMI for assessment of the risk for type 2 diabetes and CVD. The lower limit values of waist circumference (³ 31 inches for women, ³ 35 inches for men) could be adopted as normal limit values for Asian populations [9, 10, 20, 28].
As obesity affects insulin resistance, the weight loss is an important therapeutic task for individuals with overweight, pre-diabetes or type 2 diabetes.
Short-term studies have revealed that moderate weight loss (5% of the body weight) of humans with type 2 diabetes was associated with decreased insulin resistance, improved values of the glycemic and lipid status and with a decrease of the high arterial blood pressure values. Longer studies (³ 52 weeks), implementing pharmacotherapy for weight loss to adults with type 2 diabetes have detected moderate weight and HbA1C reduction, though not all studies have reported improved HbA1C values. The “Look AHEAD” survey (Action for Health in Diabetes) is a wide-scale study sponsored by prominent health institutions, aiming to determine the effect of permanent weight loss on the improvement of the glycemic status and prevention of cardiovascular problems [15, 18, 22].
The data from studies on “nutrition-diabetes” relationship confirm that the implementation of intensive programmes involving personalized advice result in a healthier life style. The more frequent contacts with individuals at risk and the recommendations for reduction of the dietary intake of energy and fats (~30% of the total energy), for regular physical activity and monitoring of their status are essential for provision of long-term weight loss with 5–7% of the initial body mass. The role of the change of the life style in the weight control at type 2 diabetes has been discussed comprehensively in a number of recent surveys [6, 7, 11, 21].
Exercises and physical activity themselves have moderate effect in weight reduction but they must be encouraged because they improve insulin sensitivity not depending on the extent of reduced body mass and lower blood sugar level. They are of particular importance for sustaining the already achieved overweight reduction. Body mass reduction induced only by behavioral changes is also insufficient but behavioral approaches could be very useful in supporting other weight reduction strategies [5, 17].
Recommendations for dietary intake at type 2 diabetes
The recommended daily allowance (RDA) for assimilable carbohydrates is 130 g/day and is based on provision of adequate glucose intake as a necessary fuel for the central nervous system, not counting on glucose production from consumed proteins or fats. Although the glucose needs of the brain could be satisfied by diets containing less carbohydrates, the long-term effects of many low-carbohydrate diets are still unclear. Similar diets eliminate many foods that are important sources of energy but also of fibers, vitamins and minerals, as well as food taste determinants.
Alternative dietary types could supply a certain amount of energy often as formulations. The use of such substituting products once or twice daily could result in substantial weight loss. Such substitutions are an important part of the intervention for body mass reduction (Look AHEAD). Similar therapies, though, must be maintained continuously if permanent weight reduction is to be achieved.
Very low-calorie diets provide < 800 calories daily and realize substantial weight loss as well as quick improvement of the glucose and lipid status of individuals with type 2 diabetes. In the most general case, when such diets are discontinued and the consumption of personally preferred foods starts again, the weight is reinstated. Thus, it must be known that the usefulness of very low-calorie diets in the therapy of type 2 diabetes is restricted and they must be applied only in combination with a structured weight reduction programme.
In conclusion, the generalization of all analyzed evidence, the following positions, engaged in nutritional recommendations at primary type 2 diabetes prevention, could be briefly presented:
- Dietary regimes with reduced intake of energy as a total and of fats, in particular, are adequate and recommendable for reduction of diabetes risk. Structured programmes are preferable in this aspect, particularly for individuals at high risk, as they accentuate on life style changes, including moderate weight loss (7% of the body weight) and regular physical activity (150 min/week).
- The diet should comply with the recommendations of expert institutions for content of more wholegrain foods containing dietary fibers in amounts about 14 g/1000 kcal of the average daily diet.
- The intake of foods with low glycemic index, in spite of the yet insufficient scientific arguments for their preventive effect.
- American Diabetes Association. Economic costs of diabetes in the US in 2012. Diabetes Care 2013; 36: 1033–1046.
- American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care 2012; 35 (Suppl. 1): S64–S71.
- Ajala O, English P, Pinkney J. Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes. Am J Clin. Nutr. 2013; 97: 505–516.
- Atkinson FS, Foster-Powell K, Brand-Miller JC. International tables of glycemic index and glycemic load values 2008. Diabetes Care 2008; 31: 2281–2283.
- Breen C, Ryan M, Gibney MJ, Corrigan M, O’Shea D. Glycemic, insulinemic, and appetite responses of patients with type 2 diabetes to commonly consumed breads. Diabetes Educ 2013; 39: 376–386.
- Brynes AE, Frost GS. Increased sucrose intake is not associated with a change in glucose or insulin sensitivity in people with type 2 diabetes. Int J Food Sci. Nutr. 2007; 58: 644–651.
- Burger KNJ, Beulens JWJ, van der Schouw YT, Sluijs I, Spijkerman AMW, Sluik D et al. Dietary fiber, carbohydrate quality and quantity, and mortality risk of individuals with diabetes mellitus. PLoS One 2012; 7: e43127.
- Daimons M, Oizumi T, Saitoh T, Kameda W, Hirata A, Yamaguchi H et al. Decreased serum levels of adiponectin are a risk factor for the progression to type 2 diabetes in the Japanese Population: the Funagata study. Diabetes Care 2003; 26: 2015–2020.
- Danaei G, Finucane MM, Lu Y, Singh GM, Cowan MJ, Paciorec CJ et al. National, regional, and global trends in fasting plasma glucose and diabetes prevalence since 1980: systematic analysis of health examination surveys and epidemiological studies with 370 country-years and 27 million participants. Lancet 2011; 378: 31–40.
- Dyson PA, Kelly T, Deakin T, Duncan A, Frost G, Harrison Z et al. Diabetes UK evidence-based nutrition guidelines for the prevention and management of diabetes. Diabetes Med 2011; 28: 1282–1288.
- Emerging Risk Factors Collaboration. Diabetes mellitus, fasting glucose, and risk of cause-specific death. N Engl J Med 2011; 364: 829–841.
- Esposito K, Maiorino MI, Ceriello A, Giugliano D. Prevention and control of type 2 diabetes by Mediterranean diet: a systematic review. Diabetes Res Clin Pract 2010; 89: 97–102.
- Global health risks. Mortality and burden of disease attributable to selected major risks. Geneva, World Health Organization, 2009.
- Global data on visual impairments 2010. Geneva, World Health Organization, 2012.
- Heianza Y, Arase Y, Fujihara K, Tsuji H, Saito K, Hsieh SD et al. Screening for pre-diabetes to predict future diabetes using various cut-off points for HbA(1c) and impaired fasting glucose: the Toranomon Hospital Health Management Center Study 4 (TOPICS 4). Diabet Med 2012; 29: e279–e285.
- Hooper L, Abdelhamid A, Moore HJ, Douthwaite W, Skeaff CM, Summerbell CD. Effect of reducing total fat intake on body weight: systematic review and meta-analysis of randomized controlled trials and cohort studies. BMJ 2012; 345: e7666.
- International Diabetes Federation. IDF Europe 2012 World Diabetes Day campaign, 2012. Available at: http://www.idf.org/regions/EUR/wdd (accessed 4 May 2013)
- Inzucchi SE, Bergenstal RM, Buse JB, Diamant M, Ferrannini E, Nauck M et al. Management of hyperglycemia in type 2 diabetes: a patient-centered approach. Position statement of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetologia 2012; 55: 1577–1596.
- Kaczmarczyk MM, Miller MJ, Freund GG. The health benefits of dietary fiber: beyond the usual suspects of type 2 diabetes mellitus, cardiovascular disease and colon cancer. Metabolism 2012; 61: 1058–1066.
- Li S, Shin HJ, Ding EL, van Dam RM. Adiponectin levels and risk of type 2 diabetes: a systematic review and meta-analysis. JAMA 2009; 302: 179–188.
- Lunn J, Buttriss JL. Carbohydrates and dietary fibre. Nutr Bull 2007; 32: 21–64.
- Mann JI, Te Morenga L. Diet and diabetes revisited, yet again. Am J Clin Nutr= 2013; 97: 453–454.
- Marsh K, Barclay A, Colagiuri S, Brand-Miller J. Glycemic index and glycemic load of carbohydrates in the diabetes diet. Curr. Diab. Rep. 2011; 11: 120–127.
- Mathers C. and Loncar D., Updated projections of global mortality and burden of disease, 2002 – 2030: data sources, methods and results, Evidence and Information for Policy, WHO, 2005.
- Rivellese AA, Boemi M, Cavalot F, Costagliola L, De Feo P, Miccoli R et al. Dietary habits in type II diabetes mellitus: how is adherence to dietary recommendations? Eur J Clin Nutr 2008; 62: 660–664.
- Seino Y, Nanjo K, Tajima N, Kadowaki T, Kashiwagi A, Araki E et al. Report of the committee on the classification and diagnostic criteria of diabetes mellitus. J Diabetes Invest 2010; 1: 212–228.
- Sheard NF, Clark NG, Brand-Miller JC, Franz MJ, Pi-Sunyer FX, Mayer-Davis E et al. Dietary carbohydrate (amount and type) in the prevention and management of diabetes: a statement by the American Diabetes Association. Diabetes Care 2004; 27: 2266–2271.
- Tabák AG, Brunner EJ, Miller MA, Karanam S, McTernan PG, Cappuccio FP et al. Low serum adiponectin predicts 10-year risk of type 2 diabetes and HbA1c independently of obesity, lipids, and inflammation: Whitehall II study. Horm Metab Res 2009; 41: 626–629.
- Vessby B, Uusitupa M, Hermansen K, Riccardi G, Rivellese AA, Tapsell LC et al. Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU study. Diabetologia 2001; 44: 312–319.
- Wheeler ML, Dunbar SA, Jaacks LM, Karmally W, Mayer-Davis EJ, Wylie-Rosett J et al. Macronutrients, food groups, and eating patterns in the management of diabetes: a systematic review of the literature, 2010. Diabetes Care 2012; 35: 434–444.
- Wild S, Roglic G, Green A, Sicree R, King H. Global prevalence of diabetes: estimates for the year 2000 and projections for 2030. Diabetes Care 2004; 27: 1047–1053.
- World Health Organization. Diet, nutrition and the prevention of chronic diseases. Report of a joint WHO/FAO expert consultation. WHO: Geneva, Switzerland 2003.EMPHASIS ON THE ROLE OF NUTRITION IN TYPE 2 DIABETESThe large-scale prevalence of diabetes mellitus in the recent decades is a challenge to medical science. Nutrition holds one of the main positions among the broad range of risk factors affecting diabetes triggering and development. The aim of this study is to present some relevant recent scientifically based recommendations for nutrition in type 2 diabetes prevention. The methodology involves analysis and assessment of scientific evidence reported during the last 10 years, published in the following scientific journals: Diabetes Care, Diabetology, Am J Clinical Nutrition, Eur. J Nutrition, Ann. Nutrition Metab. as well as in the WHO and American Diabetes Association (ADA) documents. Results and Discussion: The study analyzed the data from a number of researches on the effect of various nutritional interventions administered on groups at risk of diabetes development, pre-diabetics and patients with diabetes. The differences in the nutritional interventions depending on the type of prevention (primary, secondary, tertiary) were outlined. The implementation of structured programs, especially for individuals at high risk is recommended as in this case the emphasis is on changes in the life style, including moderate weight loss (7% of the body weight) and regular physical activity (150 min/week). Conclusion: Dietary regimes with reduced total energy intake and particularly reduced fats intake are appropriate and recommendable for decreasing type 2 diabetes risk. The awareness about the diet is an integral part of the general knowledge on diabetes as a disease and is not only necessary but also essential in achieving effective self-control.Written by: Maya VizevaPublished by: Басаранович ЕкатеринаDate Published: 12/15/2016Edition: euroasia-science_6(27)_23.06.2016Available in: Ebook