Diabetic diet

Diabetic diet refers to the diet that is recommended for people with diabetes mellitus, or high blood glucose. There is much disagreement regarding what this diet should consist of. Since carbohydrate is the macronutrient which raises blood glucose levels most significantly, the greatest debate is regarding how low in carbohydrates the diet should be. This is because although lowering carbohydrate intake will lead to reduced blood glucose levels, carbohydrates are traditionally considered the main energy source in most modern diets, and a low-carbohydrate diet is likely to contain increased amounts of calories from fat and saturated fat. Recommendations of the fraction of total calories to be obtained from carbohydrate are generally in the range of 20 to 45%, but recommendations can vary as widely as from 16 to 75% . The most agreed upon recommendation is for the diet to be low in sugar and refined carbohydrates, while relatively high in dietary fiber, especially soluble fiber. Likewise, people with diabetes may be encouraged to reduce their intake of carbohydrates that have a high glycemic index (GI), although this is also controversial. (In cases of hypoglycemia, they are advised to have food or drink that can raise blood glucose quickly, such as lucozade, followed by a long-acting carbohydrate (such as rye bread) to prevent risk of further hypoglycemia.) However, others question the usefulness of the glycemic index and recommend high-GI foods like potatoes and rice. It has been claimed that oleic acid has a slight advantage over linoleic acid in reducing plasma glucose.

History

There has been long history of dietary treatment of diabetes mellitus – dietary treatment of diabetes mellitus was used in Egypt since 3,500 B.C., and was used in India by Sushruta and Charaka more than 2000 years ago. In the eighteenth century, John Rollo argued that calorie restriction in the diabetic diet could reduce glycosuria in diabetes. However, more modern history of the diabetic diet may begin with Frederick Madison Allen, who, in the days before insulin was discovered, recommended that people with diabetes ate only a low-calorie diet to prevent ketoacidosis from killing them. This was an approach which did not actually cure diabetes but merely extended life by a limited period. The first use of insulin by Frederick Banting in 1922 changed things, and at last allowed patients more flexibility in their eating.

Exchange scheme

In the 1950s, the American Diabetes Association, in conjunction with the U.S. Public Health Service, introduced the "exchange scheme". This allowed people to swap foods of similar nutritional value (e.g. carbohydrate) for another, so, for example, if wishing to have more than normal carbohydrates for dessert, one could cut back on potatoes in one's first course. The exchange scheme was revised in 1976, 1986 and 1995.

Later developments

However, not all diabetes dietitians today recommend the exchange scheme. Instead, they are likely to recommend a typical healthy diet: one high in fiber, with a variety of fruit and vegetables, and low in both sugar and fat, especially saturated fat. A diet that is high in plant fibre was recommended by James Anderson (Anderson & Ward, 1979; cited in Murray & Pizzorno, 1990). This may be understood as continuation of the work of Denis Burkitt and Hugh Trowell on dietary fibre, which in turn, may be understood as a continuation of the work of Price (Murray & Pizzorno, 1990). It is still recommended that people with diabetes consume a diet that is high in dietary fiber.

In 1976, Nathan Pritikin opened a centre where patients were put on programme of diet and exercise (the Pritikin Program). This diet is high on carbohydrates and fibre, with fresh fruit, vegetables, and whole grains. A study at UCLA in 2005 showed that it brought dramatic improvement to a group of people with diabetes or pre-diabetes in only three weeks, so that about half no longer met the criteria for the disease.

On the other hand, in 1983, Richard K. Bernstein began treating people with diabetes and pre-diabetes successfully with a very low carbohydrate diet, avoiding fruit, added sugar, and starch. Both the Pritikin approach and the Bernstein approach prescribe exercise.

An approach that has been popular with some people with type one diabetes mellitus since 2000 is known as DAFNE (Dose Adjustment for Normal Eating). This approach involves estimating how much carbohydrates there will be in a meal and modifying the amount of insulin one injects before meal accordingly. An equivalent approach has for people with type two diabetes mellitus is known as DESMOND, which stands for Diabetes Education and Self-Management for On-Going and Newly Diagnosed (diabetes). DAFNE has its own newsletter and has received recommendation.

Carbohydrates

The American Diabetes Association in 1994 recommended that 60–70% of caloric intake should be in the form of carbohydrates. As mentioned above, this is controversial, with some researchers claiming that 40% or even less is better, while others claim benefits for a high-fiber, 75% carbohydrate diet.

An article summarizing the view of the American Diabetes Association contains the statement: "Sucrose-containing foods can be substituted for other carbohydrates in the meal plan or, if added to the meal plan, covered with insulin or other glucose-lowering medications. Care should be taken to avoid excess energy intake." Sucrose does not increase glycemia more than the same number of calories taken as starch. It is not recommended to use fructose as a sweetener. Benefits may be obtained by consumption of dietary fibre in conjunction with carbohydrate; as Francis (1987) points out, evidence suggests that carbohydrate consumed with dietary fiber will have a less major impact on glycemic rise than the same amount of carbohydrate consumed alone.

What has not generally been included in diabetic diet recommendations is the variation in effect from different carbohydrates. It has been recommended that carbohydrates eaten by people with diabetes should be complex carbohydrates.

Despite a common belief that table sugar contributes to the development of diabetes, it has medium (55–69) glycemic index that actually produces lower blood glucose levels than the same number of calories obtained from some other sources of carbohydrates. The Canadian Diabetes Association recommended that table sugar be included as part of the diabetes diet.

Some studies have suggested that adding vinegar to food may help to prevent carbohydrates putting up blood sugar too dramatically.

Low-carbohydrate alternatives

Some studies show that a low-carbohydrate diet or low GI diet may be effective in dietary management of type 2 diabetes, as both approaches prevent blood sugars from spiking after eating.

Richard K. Bernstein is critical of the standard American Diabetes Association diet plan. His plan includes very limited carbohydrate intake (30 grams per day) along with frequent blood glucose monitoring, regular strenuous muscle-building exercise, and, for people using insulin, frequent small insulin injections if needed. His treatment target is "near normal blood sugars" all the time.

Another critic of the ADA program is futurologist and transhumanist Ray Kurzweil, who together with Terry Grossman co-authored Fantastic Voyage: Live Long Enough to Live Forever (published 2004). They describe the ADA guidelines as "completely ineffective". Their observations are that the condition, particularly in its early stages can be controlled through a diet which has sharply reduced carbohydrate consumption. Their guidelines for patients with type 2 diabetes is a diet that includes a reduction of carbohydrates to one sixth of total caloric intake and elimination of high glycemic load carbohydrates. As someone who was previously diagnosed with diabetes but who no longer has symptoms of the disease, Kurzweil is a firm advocate of this approach. However, Kurzweil's prescription changed somewhat between his 1993 book The 10% Solution for a Healthy Life in which he recommended that only 10% of calories should come from fat, and Fantastic Voyage which recommends 25%.

Vegan/vegetarian

Based on the evidence that the incidence of diabetes is lower in vegetarians, some studies have investigated vegan interventions. These studies have shown that a vegan diet may be effective in managing type 2 diabetes. Plant-based diets tend to be higher in fiber, which slows the rate sugar is absorbed into the bloodstream. Switching people with diabetes to a vegan diet lowered hemoglobin A1C and LDL levels. A vegan diet may improve blood filterability. Vegan diets may lower advanced glycation endproducts. Limited evidence suggests that reductions in iron stores increase insulin sensitivity. A vegan diet provides iron in its nonheme form, which is somewhat less absorbable than heme iron.

Diabetes U.K. state that diabetes should not prevent people from going vegetarian – in fact, it may be beneficial for people with diabetes to go vegetarian, as this will cut down on saturated fats. Recent evidence suggests that people with diabetes may benefit from as many as eight portions of fruit and vegetable a day.

Due to their high levels of dietary fibre certain foods are considered particularly beneficial for people with diabetes such as legumes, nuts, fruits, and vegetables.

Individuals with type 2 diabetes on a low-fat vegan diet or a diet following ADA guidelines improved glycemic control; however, the changes were greater in the vegan group.

Timing of meals

For people with diabetes, healthy eating is not simply a matter of "what one eats", but also when one eats. The question of how long before a meal one should inject insulin is asked in Sons ken, Fox and Judd (1998). The answer is that it depends upon the type of insulin one takes and whether it is long, medium or quick-acting insulin. If patients check their blood glucose at bedtime and find that it is low, for example below 6 millimoles per Liter (108 mg/dL), it is advisable that they take some long-acting carbohydrate before retiring to bed to prevent night-time hypoglycemia. Night sweats, headaches, restless sleep, and nightmares can be a sign of nocturnal hypoglycemia, and patients should consult their doctor for possible adjustments to their insulin routine if they find that this is the case. Counterintuitively, another possible sign of nocturnal hypoglycemia is morning hyperglycemia, which actually occurs in response to blood sugar getting too low at night. This is called the Somogyi Effect.

Special diabetes products

Recently, Diabetes UK have warned against purchase of products that are specially made for people with diabetes, on grounds that:

• They may be expensive,
• They may contain high levels of fat
• They may confer no special benefits to people who have diabetes.

It should also be noted that NICE, the National Institute for Health and Clinical Evidence (based in the United Kingdom), advises doctors and other health professionals to "Discourage the use of foods marketed specifically for people with diabetes".

Research has shown the Maitake mushroom (Grifola frondosa) has a hypoglycemic effect, and may be beneficial for the management of diabetes. The reason Maitake lowers blood sugar is because the mushroom naturally acts as an alpha glucosidase inhibitor. Other mushrooms like Reishi, Agaricus blazei, Agrocybe cylindracea and Cordyceps have been noted to lower blood sugar levels to a certain extent, although the mechanism is currently unknown.

Alcohol and drugs

Moderation is advised with regard to consuming alcohol and the use of some drugs. Alcohol inhibits glycogenesis in the liver and some drugs inhibit hunger symptoms. This, together with impaired judgment, memory and concentration caused by some drugs can lead to hypoglycemia. People with diabetes who take insulin or tablets such as sulphonylureas should not, therefore, ever consume alcohol on an empty stomach, but take some starchy food (such as bread or potato crisps) at the same time as consumption of alcohol.

Specific diets

The Pritikin Diet consists of fruit, vegetables, whole grains, and so on, and is high in carbohydrates and roughage. The diet is accompanied by exercise.

G.I. Diet – lowering the glycemic index of one's diet can improve the control of diabetes. This includes avoidance of such foods as potatoes cooked in certain ways, and white bread, and instead favoring multi-grain and sourdough breads, legumes and whole grains—foods that are converted more slowly to glucose in the bloodstream.

Low Carb Diet – It has been suggested that the removal of carbohydrates from the diet and replacement with fatty foods such as nuts, seeds, meats, fish, oils, eggs, avocados, olives, and vegetables may help reverse diabetes. Fats would become the primary calorie source for the body, and complications due to insulin resistance would be minimized.

High fiber diet – It has been shown that a high fiber diet works better than the diet recommended by the American Diabetes Association in controlling diabetes, and may control blood sugar levels with the same efficacy as oral diabetes drugs.

Paleolithic diet – The Paleolithic diet has been shown to improve glucose tolerance in humans with diabetes type 2, humans with ischemic heart disease and glucose intolerance, and in healthy pigs.

Vegan diet – A low-fat vegan diet improves glycemic control similar to the ADA diet.

Natural Foods - the American Diabetes Association has endorsed a natural foods approach to managing diabetes, advocating “fresh is best” and avoiding artificial sweeteners, instead substituting measured amounts of fresh fruit or raw sugar.

See also

• Diabetes management
• Diabetic diet (low-carb)
• Glycemic index
• Glycemic efficacy
• Low GI Diet
• Low-carbohydrate diet
• National Institutes of Health

Further reading

• Murray, M. & Pizzorno, J. (1990). Encyclopaedia of Natural Medicine. London: Littlebrown and Company. ISBN 1-85605-498-5
• Natural Remedies For Diabetes. (December 2015). Diabetes treatment guidelines form Howtogreat.