Diabetes mellitus is a disorder characterized by abnormally high blood glucose levels. People with diabetes cannot properly process glucose, a sugar the body uses for energy. As a result, glucose tends to move inefficiently from the bloodstream to the tissues of the body where it is needed. Therefore, at the same time blood glucose levels are elevated, the rest of the body can be starved for glucose. Diabetes can lead to poor wound healing, higher risk of infections, and damage to the eyes, kidneys, nerves, and heart. In type 1 diabetes, also called childhood-onset or insulin-dependent diabetes, damage to the pancreas results in an inability of that organ to make the hormone insulin. Most risk factors discussed in this section do not apply to type 1 diabetes.
Type 2 diabetes is also called adult-onset or non-insulin-dependent diabetes mellitus. In people with this condition, the pancreas is capable of making normal amounts of the hormone insulin. Despite the presence of normal or even elevated levels of insulin in type 2 diabetes patients, however, the body does not efficiently move glucose out of the bloodstream and into the cells. This lack of sensitivity to insulin is called insulin resistance--the hallmark of type 2 diabetes. Insulin resistance not severe enough to be labeled diabetes is sometimes called glucose intolerance and is considered a pre-diabetic condition. Risk factors for glucose intolerance are virtually identical to risk factors for type 2 diabetes. These risk factors are discussed in this section.
The risk of type 2 diabetes increases with age beginning after age 30. Nearly 20% of the U.S. population aged 65-74 has diabetes.1 Pre-diabetic conditions also increase in older people and are thought to contribute to heart disease and other health problems.2
Moderate drinking in healthy people improves glucose tolerance and reduces the risk of type 2 diabetes.3, 4, 5, 6 In contrast, alcohol has been reported to worsen glucose tolerance in the elderly.7 For young, healthy people, light drinking will at least not increase the risk of diabetes, though as for all people, heavy drinking should be avoided.
Both male and female infants with low birthweight appear to be at increased risk for eventually developing type 2 diabetes.8,9 The risk is slightly less than double for newborns weighing under five pounds compared to those weighing nine pounds.
Despite the body's need for insulin when carbohydrate is eaten, diets high in total carbohydrates do not necessarily increase the risk of type 2 diabetes.10,11 However, researchers have found that high-sugar diets may worsen glucose tolerance in animals12 and humans,13 though the amounts of sugar used in these studies in proportion to other foods are much larger than is typically found in human diets. Years ago, one researcher reported an increase in diabetes among Yemenite Jews who had migrated from a region where no sugar was eaten to one in which they ate a diet including sugar.14 However, other factors, such as weight gain, may explain the increased risk that occurred in this group.15 Other studies have found no independent relationship between sugar intake and the development of glucose intolerance.16
Eating carbohydrate-containing foods, whether high in sugar or high in starch (such as bread, potatoes, cold breakfast cereals, and rice), temporarily raises blood sugar and insulin levels.17 The blood sugar-raising effect of a food, called its "glycemic index," depends on how rapidly its carbohydrate is absorbed. Many starchy foods have a glycemic index similar to sucrose (table sugar).18 People eating large amounts of foods with high glycemic indexes (such as those mentioned above), have been reported to be at increased risk of type 2 diabetes.19,20 On the other hand, eating a diet high in carbohydrate-rich foods with low glycemic index has associated with a low risk of type 2 diabetes.21,22,23 Due mostly to the health-promoting effects of fiber found beans, peas, fruit, and oats, these foods have low glycemic indices despite their high carbohydrate content.
Diet: Cow's Milk
Several preliminary studies have found that early introduction of cow's milk formula feeding increases the risk of developing type 1 diabetes, although contradictory results have also been published.24,25 A study of 821 Finnish children (including 435 full-term diabetics) showed that early introduction of cow's milk formula feeding (before 3 months of age vs. after 3 months of age) was associated with increased risk of type 1 diabetes.26
People in many parts of the world who eat traditional diets high in fiber have a low risk of type 2 diabetes.27 Vegetarians, who typically have high-fiber diets, have been reported to be at low risk of being diagnosed with type 2 diabetes.28 While some research has not revealed an association between total fiber intake and protection from diabetes,29,30 specific fiber-containing foods such as peas and beans31 and whole-grain products32,33 have been associated with a decreased risk of type 2 diabetes. Some of these foods (peas and beans) contain a type of fiber that slows down the absorption of glucose into the blood, protecting the body from large sudden increases in glucose; this may explain why they help protect against type 2 diabetes.34 How other foods (like whole-grain products) that do not contain much of this type of fiber help prevent type 2 diabetes is unclear.35
Diets high in fat, especially saturated fat, worsen glucose tolerance and increase the risk of type 2 diabetes,36,37,38,39 an effect that is not simply the result of weight gain caused by eating high-fat foods. Saturated fat is found primarily in meat, dairy fat, and poultry skins and dark meat.
In contrast, glucose intolerance has been improved by diets high in monounsaturated oils.40,41 One of the simplest ways to increase intake of monounsaturates is to add olive oil to the diet instead of other vegetable oils, butter, and margarine.
Chromium plays an important role in both the function of insulin and the control of blood glucose.42 Chromium deficiency causes glucose intolerance, and some, though not all, studies have shown that glucose tolerance improves in nondiabetics given chromium supplements.43 Chromium levels in the human body decrease with age, corresponding with increases in the risk of type 2 diabetes,44 though these two facts are not necessarily related. While increased chromium intake might help prevent diabetes in people with high risk for the disease,45 no research has yet investigated the possibility of this effect. Despite the lack of definitive research, however, many doctors recommend 200 mcg of chromium per day as a way to help reduce the risk of type 2 diabetes.
People with a family history of the diabetes are at increased risk for the disease,46 though not all type 2 diabetics have a family history.47 People with a family history of diabetes should adopt dietary and lifestyle changes that reduce their risk for diabetes.
Women who have had diabetes temporarily during pregnancy (gestational diabetes) are at increased risk for developing type 2 diabetes.48 Women with a personal history of gestational diabetes should adopt dietary and lifestyle changes that reduce their risk for type 2 diabetes.
Most people who develop type 2 diabetes are obese.49 More precisely, people with excess abdominal fat (as opposed to fat accumulation in the thighs and buttocks) have an especially high risk of diabetes, even if their body weight is normal.50,51 Although excess abdominal fat does not stop insulin formation,52 it does make the body less sensitive to insulin.53 Excess weight can induce glucose intolerance in otherwise healthy people,54 and weight loss reverses this problem.55 One study found that people who were not overweight but simply had a strong family history of type 2 diabetes could reduce their risk of becoming diabetic by losing weight.56
Increased weight gain in infancy may increase the risk of developing type 1 diabetes in childhood.57,58 In a study of 435 diabetic children and 386 healthy children, increased weight was associated with a 1.5-fold increase in the risk of developing type 1 diabetes.59
Impaired Glucose Tolerance
Many people who are not diabetic have glucose intolerance--blood sugar levels that are slightly above normal, accompanied by elevated blood insulin levels.60,61 People with impaired glucose tolerance are at increased risk for type 2 diabetes, though only 20-50% actually develop the disease.62 Most studies find that weight loss and/or exercise reduces the risk of becoming diabetic in people with impaired glucose tolerance.63,64
Type 2 diabetes is much more common in Native Americans and is also higher in blacks and Hispanics compared to whites.65
Sedentary people are more likely and exercisers less likely to develop type 2 diabetes.66 This link is not completely explained by the effect of exercise on body weight.676869 Exercise probably helps lower diabetes risk in part by helping to control body fat70 while maintaining or improving insulin sensitivity.71 One study found exercise alone to be as effective as exercise combined with dietary changes in preventing diabetes in people with glucose intolerance.72 Another study found that exercise combined with an improved diet reduced death rates in people with glucose intolerance.73
Both male and female smokers are more likely to become diabetic compared to nonsmokers.74,75
1. Harris MI. Undiagnosed NIDDM: clinical and public health issues. Diabetes Care 1993;16:642-52 [review].
2. Preuss HG. Effects of glucose/insulin perturbations on aging and chronic disorders of aging: the evidence. J Am Coll Nutr 1997;16:397-403.
3. Kiechl S, Willeit J, Poewe W, et al. Insulin sensitivity and regular alcohol consumption: large, prospective, cross sectional population study Bruneck study. BMJ 1996;313:1040-4.
4. Facchini F, Chen Y-DI, Reaven GM. Light-to-moderate alcohol intake is associated with enhanced insulin sensitivity. Diabetes Care 1994;17:115.
5. Rimm EB, Chan J, Stampfer MJ, et al. Prospective study of cigarette smoking, alcohol use, and the risk of diabetes in men. BMJ 1995;310:555-9.
6. Stampfer MJ, Colditz GA, Willett WC, et al. A prospective study of moderate alcohol drinking and risk of diabetes in women. Am J Epidemiol 1988;128:549-58.
7. Goden G, Chen X, Desantis R, et al. Effects of ethanol on carbohydrate metabolism in the elderly. Diabetes 1993;42:28-34.
8. Rich-Edwards JW, Colditz GA, Stampfer MJ, et al. Birthweight and the risk for type 2 diabetes mellitus in adult women. Ann Intern Med 1999;130:278-84.
9. Lithell HO, McKeigue PM, Berglund L, et al. Relation of size at birth to non-insulin dependent diabetes and insulin concentrations in men aged 50-60 years. BMJ 1996;312:406-10.
10. Colditz GA, Manson JE, Stampfer MJ, et al. Diet and risk of clinical diabetes in women. Am J Clin Nutr 1992;55:1018-23.
11. Feskens EJ, Bowles CH, Kromhout D. Carbohydrate intake and body mass index in relation to the risk of glucose intolerance in an elderly population. Am J Clin Nutr 1991;54:136-40.
12. Wright DW, Hansen RI, Mondon CE, Reaven GM. Sucrose-induced insulin resistance in the rat: modulation by exercise and diet. Am J Clin Nutr 1983;38:879-83.
13. Reiser S, Hallfrisch J, Fields M, et al. Effects of sugars on indices of glucose tolerance in humans. Am J Clin Nutr 1986;43:151-9.
14. Cohen AM et al. Change of diet of Yemenite Jews in relation to diabetes and ischaemic heart disease. Lancet 1961;2:1399-401.
15. Cohen AM, Fidel J, Cohen B, et al. Diabetes, blood lipids, lipoproteins, and change of environment: restudy of the "new immigrant Yemenites" in Israel. Metabolism 1979;28:716-28.
16. Feskens EJ, Bowles CH, Kromhout D. Carbohydrate intake and body mass index in relation to the risk of glucose intolerance in an elderly population. Am J Clin Nutr 1991;54:136-40.
17. Wolever TMS, Brand Miller J. Sugars and blood glucose control. Am J Clin Nutr 1995;62:212S-7S [review].
18. Wolever TMS, Brand Miller J. Sugars and blood glucose control. Am J Clin Nutr 1995;62:212S-7S [review].
19. Salmeron J, Manson JE, Stampfer MJ, et al. Dietary fiber, glycemic load, and risk of non-insulin-dependent diabetes mellitus in women. JAMA 1997;277:472-7.
20. Salmeron J, Ascherio A, Rimm EB, et al. Dietary fiber, glycemic load, and risk of NIDDM in men. Diabetes Care 1997;20:545-50.
21. Feskens EJ, Virtanen SM, Rasanen L, et al. Dietary factors determining diabetes and impaired glucose tolerance. A 20-year follow-up of the Finnish and Dutch cohorts of the Seven Countries Study. Diabetes Care 1995;18:1104-12.
22. Salmeron J, Manson JE, Stampfer MJ, et al. Dietary fiber, glycemic load, and risk of non-insulin-dependent diabetes mellitus in women. JAMA 1997;277:472-7.
23. Salmeron J, Ascherio A, Rimm EB, et al. Dietary fiber, glycemic load, and risk of NIDDM in men. Diabetes Care 1997;20:545-50.
24. Gerstein HC. Cow's milk exposure and type I diabetes mellitus. A critical overview of the clinical literature. Diabetes Care 1994;17:13-9 [Review].
25. Akerblom HK, Knip M. Putative environmental factors in Type 1 diabetes. Diabetes Metab Rev 1998;14:31-67 [Review].
26. Hypponen E, Kenward MG, Virtanen SM, et al. Infant feeding, early weight gain, and risk of type 1 diabetes. Diabetes Care 1999;22:1961-5.
27. Trowell HC, Burkitt D, Heaton K, eds. Dietary Fiber, Fiber-Depleted Foods and Disease. New York, NY: Academic Press; 1985.
28. Snowdon DA, Phillips RL. Does a vegetarian diet reduce the occurrence of diabetes? Am J Publ Health 1985;75:507-12.
29. Marshall JA, Weiss NS, Hamman RF. The role of dietary fiber in the etiology of non-insulin-dependent diabetes mellitus. The San Luis Valley Diabetes Study. Ann Epidemiol 1993;3:18-26.
30. Colditz GA, Manson JE, Stampfer MJ, et al. Diet and risk of clinical diabetes in women. Am J Clin Nutr 1992;55:1018-23.
31. Feskens EJ, Virtanen SM, Rasanen L, et al. Dietary factors determining diabetes and impaired glucose tolerance. A 20-year follow-up of the Finnish and Dutch cohorts of the Seven Countries Study. Diabetes Care 1995;18:1104-12.
32. Salmeron J, Manson JE, Stampfer MJ, et al. Dietary fiber, glycemic load, and risk of non-insulin-dependent diabetes mellitus in women. JAMA 1997;277:472-7.
33. Salmeron J, Ascherio A, Rimm EB, et al. Dietary fiber, glycemic load, and risk of NIDDM in men. Diabetes Care 1997;20:545-50.
34. Jenkins DJA, Wolever TMS, Leeds AR, et al. Dietary fibers, fiber analogues and glucose tolerance: importance of viscosity. BMJ 1978;2:1744-6.
35. Jenkins DJ, Jenkins AL. Dietary fiber and the glycemic response. Proc Soc Exp Biol Med 1985;180:422-31 [review].
36. Feskens EJ, Virtanen SM, Rasanen L, et al. Dietary factors determining diabetes and impaired glucose tolerance. A 20-year follow-up of the Finnish and Dutch cohorts of the Seven Countries Study. Diabetes Care 1995;18:1104-12.
37. Feskens EJ, Kromhout D. Habitual dietary intake and glucose tolerance in euglycaemic men: the Zutphen Study. Int J Epidemiol 1990;19:953-9.
38. Marshall JA, Hoag S, Shetterly S, et al. Dietary fat predicts conversion from impaired glucose tolerance to NIDDM. The San Luis Valley Diabetes Study. Diabetes Care 1994;17:50-6.
39. Marshall JA, Hamman RF, Baxter J. High-fat, low-carbohydrate diet and the etiology of non-insulin-dependent diabetes mellitus: the San Luis Valley Diabetes Study. Am J Epidemiol 1991;134:590-603.
40. Uusitupa M, Schwab U, Makimattila S, et al. Effects of two high-fat diets with different fatty acid compositions on glucose and lipid metabolism in healthy young women. Am J Clin Nutr 1994;59:1310-6.
41. Sarkkinen E, Schwab U, Niskanen L, et al. The effects of monounsaturated-fat enriched diet and polyunsaturated-fat enriched diet on lipid and glucose metabolism in subjects with impaired glucose tolerance. Eur J Clin Nutr 1996;50:592-8.
42. Mertz W. Interaction of chromium with insulin: a progress report. Nutr Rev 1998;56:174-7 [review].
43. Anderson RA. Chromium, glucose intolerance and diabetes. J Am Coll Nutr 1998;17:548-55 [review].
44. Davies S, Howard JM, Hunnisett A, et al. Age-related decreases in chromium levels in 51,665 hair, sweat, and serum samples from 40,872 patients - implications for the prevention of cardiovascular disease and type II diabetes mellitus. Metabolism 1997;46:469-73.
45. Linday LA. Trivalent chromium and the diabetes prevention program. Med Hypotheses 1997;49:47-9.
46. Lubin MB, Lin HJ, Vadheim CM, et al. Genetics of common diseases of adulthood. Implications for prenatal counseling and diagnosis. Clin Perinatol 1990;17:889-910.
47. Gnanalingham MG, Manns JJ. Patient awareness of genetic and environmental risk factors in non-insulin-dependent diabetes mellitus--relevance to first-degree relatives. Diabet Med 1997;14:660-2.
48. Harris MI. Gestational diabetes may represent discovery of preexisting glucose intolerance. Diabetes Care 1988;11:402-11.
49. Isida K, Mizuno A, Murakami T, Shima K. Obesity is necessary but not sufficient for the development of diabetes mellitus. Metabolism 1996;45:1288-95.
50. Ruderman N, Chisholm D, Pi-Sunyer X, et al. The metabolically obese, normal-weight individual revisited. Diabetes 1998;47:699-713.
51. Carey VJ, Walters EE, Colditz GA, et al. Body fat distribution and risk of non-insulin-dependent diabetes mellitus in women. The Nurses' Health Study. Am J Epidemiol 1997;145:614-9.
52. Casassus P, Fontbonne A, Thibult N, et al. Upper-body fat distribution: a hyperinsulinemia-independent predictor of coronary heart disease mortality. Arterioscler Thromb 1992;1387-92.
53. Karter AJ, Mayer-Davis EJ, Selby JV, et al. Insulin sensitivity and abdominal obesity in African-American, Hispanic, and non-Hispanic white men and women. Diabetes 1996;45:1547-55.
54. Park KS, Hree BD, Lee K-U, et al. Intra-abdominal fat is associated with decreased insulin sensitivity in healthy young men. Metabolism 1991;40:600-3.
55. Long SD, Swanson MS, O'Brien K, et al. Weight loss in severely obese subjects prevents the progression of impaired glucose tolerance to type II diabetes. Diabetes Care 1994;17:372.
56. Viswanathan M, Snehalatha C, Viswanathan V, et al. Reduction in body weight helps to delay the onset of diabetes even in non-obese with strong family history of the disease. Diabetes Res Clin Pract 1997;35:107-12.
57. Baum JD, Ounsted M, Smith MA. Weight gain in infancy and subsequent development of diabetes mellitus in childhood (Abstract). Lancet 1975;2:866.
58. Johansson C, Samuelsson U, Ludvigsson J. A high weight gain early in life is associated with an increased risk of type 1 (insulin-dependent) diabetes mellitus. Diabetologia 1994;37:91-4.
59. Hypponen E, Kenward MG, Virtanen SM, et al. Infant feeding, early weight gain, and risk of type 1 diabetes. Diabetes Care 1999;22:1961-5.
60. Harris MI. Epidemiologic studies on the pathogenesis of non-insulin-dependent diabetes mellitus (NIDDM). Clin Invest Med 1995;18:231-9 [review].
61. American Diabetes Association. American Diabetes Association: clinical practice recommendations 1997. Diabetes Care 1997;20:S1-70 [review].
62. Alberti KG. Impaired glucose tolerance: what are the clinical implications? Diabetes Res Clin Pract 1998;40:S3-8.
63. Pan XR, Li GW, Hu YH, et al. Effects of diet and exercise in preventing NIDDM in people with impaired glucose tolerance. The Da Qing IGT and Diabetes Study. Diabetes Care 1997;20:537-44.
64. Melander A. Review of previous impaired glucose tolerance intervention studies. Diabet Med 1996;13(3 Suppl 2):S20-2 [review].
65. American Diabetes Association. Diabetes 1996 vital statistics. Alexandria, VA: American Diabetes Association, 1995.
66. Helmrich SP, Ragland DR, Leung RW, Paffenbarger RS. Physical activity and reduced occurrence of non-insulin-dependent diabetes mellitus. N Engl J Med 1991;325:147-52.
67. Manson JE, Nathan DM, Krolewski AS, et al. A prospective study of exercise and incidence of diabetes among US male physicians. JAMA 1992;268:63-7.
68. Manson JE, Rimm EB, Stampfer MJ, et al. Physical activity and incidence of non-insulin-dependent diabetes mellitus in women. Lancet 1991;338:774-8.
69. Ruderman N, Chisholm D, Pi-Sunyer X, et al. The metabolically obese, normal-weight individual revisited. Diabetes 1998;47:699-713.
70. Hersey III WC, Graves JE, Pollack ML, et al. Endurance exercise training improves body composition and plasma insulin responses in 70- to 79-year-old men and women. Metabol 1994;43:847-54.
71. Rasmussen OW, Lauszus FF, Hermansen K. Effects of postprandial exercise on glycemic response in IDDM subjects. Diabetes Care 1994;17:1203.
72. Pan XR, Li GW, Hu YH, et al. Effects of diet and exercise in preventing NIDDM in people with impaired glucose tolerance. The Da Qing IGT and Diabetes Study. Diabetes Care 1997;20:537-44.
73. Eriksson KF, Lindgarde F. No excess 12-year mortality in men with impaired glucose tolerance who participated in the Malmo Preventive Trial with diet and exercise. Diabetologia 1998;41:1010-6.
74. Rimm EB, Manson JE, Stampfer MJ, et al. Cigarette smoking and the risk of diabetes in women. Am J Public Health 1993;83:211-4.
75. Rimm EB, Chan J, Stampfer MJ, et al. Prospective study of cigarette smoking, alcohol use, and the risk of diabetes in men. BMJ 1995;310:555-9.
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