The estimate of people with diabetes
mellitus (DM) in the year 2014 was 387 million worldwide, with type 2 DM
making up about 90% of the cases. This has in turn accounted for the
increase in number of deaths, as diabetes is a risk factor for diseases
like cardiovascular diseases, doubling a person's risk of death [2].
Diabetes is rapidly emerging as a global health care problem that
threatens to become the 7th leading cause of death in the world by the
year 2030; the number of people with diabetes worldwide is projected to
increase from 171 million in 2000 to 366 million by 2030, as shown in
the below graphical map [6].
Millions of Cases of Diabetes in 2000 and Projections for 2030, with Projected Percent Changes
Diabetes is a chronic metabolic disorder, where role of insulin
in the body is disturbed. In cases where, the insulin is not produced by
pancreas in the individuals is termed as Type 1 diabetes, while condition where he insulin produced is not well utilized in the body to bring down blood glucose is termed as Type 2 diabetes.
In both cases the blood glucose remains relatively very high than
normal levels. Another condition where the blood glucose level is high
but not as much to consider them as diabetic levels is called pre-diabetes. These increased blood glucose conditions can however be prevented, delayed or managed by healthy food habits and daily physical exercises [1].
Low GI
Medium GI
High GI
0-55
56-69
70 or greater
Table: Low glycemic foods with their glycemic values [24, 25]:
Low glycemic foods
Estimated Glycemic load(per serving size)
Low glycemic foods
Estimated Glycemic load(per serving size
Fenugreek
2
Raspberries
3
Quinoa,cooked
18
Blackberries
4
Barley,pearl,cooked
19
Grapes
5
Ragi
23
Cranberries
2
Wild garlic
22
Cherries,sweet,raw
7
Bittermelon
1
Dates
9
Okra,cooked,boiled,drained,with salt
2
Low fat cheese
5
Blueberries
6
Milk(fat free and skim)
9
Strawerries
3
Yogurt,plain,lowfat,12 grams protien per 8 ounce
10
Fenugreek:
Fenugreek (Trigonella foenum-graecum) has a
historical use for a variety of health condition. The dried seeds of
fenugreek can be powdered and taken orally for health benefits.
Fenugreek is studied to have 2 main beneficial components for diabetics:
diosgenin and 4-hydroxyisoleucine. In one study, different doses of
diosgenin was administered orally to group of diabetic rats and normal
healthy rats; the 45th day results showed significant decline in blood
glucose level and a significant increase in plasma insulin level. These
effects were compared with glibenclamide, a standard oral hypoglycemia
drug [4]. In another study, insulin resistant-human liver cells were
treated with 4-hydroxyisoleucine resulting in increased glycogen levels
in the cells as a result of reversal of insulin resistance [5].
Quinoa:
Quinoa (Chenopodium quinoa Willd) is
nutrition packed vegetable seed, often a choice of substitute for whole
grain. The nutrients found in quinoa are riboflavin (vitamin B2),
quercetin, tocopherols, polyphenols, saponins, phytosterols, minerals,
vitamins, anti-oxidants and high fiber content altogether making it a
great choice for the diabetics [9]. Quinoa was studied for its potential
type-2 diabetes mellitus (T2DM)- hyperglycemia-relevant
alpha-glucosidase and alpha-amylase activities, quercetin derivatives
and antioxidant activity. These pseudograins proved to be a part
effective dietary strategy for managing T2DM as they were rich in
quercetin and had the highest antioxidant activity [10].
Barley:
Barley (Hordeum vulgare L.) is a multi-nutrient cereal grain,
which has a nutlike flavor and an appealing chewy consistency when
cooked. It is known not only for its rich content of molybdenum,
manganese, dietary fiber, and selenium, but also for its fair amounts of
copper, vitamin B1, chromium, phosphorus, magnesium, and niacin. Its
role in diabetes management is proved through studies. A particular
study proved that the starch digestibility rate is the least in barley
compared to its counterpart grains like wheat, rice, oats and corn. This
also accounts for the high phenolic content of barley making it an
ideal snack to modulate glycemic response [11]. Clinical trials on 56
diabetic patients with 3 months follow-up studies showed decreasing
plasma glucose levels and glycosylated hemoglobin (HbA1c) with every
consecutive months [12].
Ragi:
Ragi, aslo called finger millet (Eleusine
coracana L.) is a deep red cereal and are tiny grain like appearance. It
has been extensively studied for its nutrition and role in maintain
good health is the last few years. It is found to be a good source of
thiamine, iron, calcium, rich in dietary fiber, low in fat content,
hence it is food of low glycemic index gaining advantage of bring
anti-diabetic. A study trial on 6 non-insulin dependent diabetes
mellitus (NIDDM) subjects consuming finger millet based diets showed
significant lower plasma glucose levels accounting to the higher fiber
content of finger millet compared to rice and wheat [13]. The
carbohydrates present in finger millet are slowly digested and absorbed
into the system and hence, regular consumption of finger millet is known
to reduce the risk of diabetes mellitus [14].
Wild garlic:
Wild garlic (Tulbaghia violacea) is an
herbaceous plant with garlic-like odor, mainly grown in South African
countries. It is well known as an ornamental plant, its bulbs and leaves
being the edible parts for therapeutic purposes. Study on effects of
aqueous extract of T. violacea on Chang liver cells showed significant
increased glucose uptake activity [15]. Another study on diabetic rat
models showed treatment by methanolic extracts of the wild garlic
resulted in significant decrease in fasting blood glucose levels,
improved glucose tolerance and significant increase in plasma insulin
and liver glycogen content compared to non treated diabetic group of
rats [16].
Bitter melon:
Bitter gourd (Momordica charantia) or
Balsam pear is an edible fruit pod, mainly a part of Asian foods. As the
name goes it is very bitter in taste and found to have health
beneficial roles. Studied for its potential in diabetes management, it
contains insulin activators like momordicine II and
3-hydroxycucurbita-5, 24-dien-19-al-7, 23- di-O-β-glucopyranoside; and
hypoglycemic agents like charantin, polypeptide-p and vicine [7]. A
4-week, double-blind trial on type 2 diabetes patients showed that a
dosage of 2000 mg/day of powdered bitter melon had modest hypoglycemic
effects and the results were comparably closer to the effects of the
anti-diabetic drug metformin 1000 mg/day [8]. The anti-diabetic effects
of bitter melon are seen only at therapeutic doses, while high doses may
exert inhibitory effects.
Okra:
Also commonly known as lady’s finger
(Abelmoschus esculentus), is a slender green vegetable with nutritious
pods inside them. It is rich in vitamins and minerals, including
vitamins A, B, C, E, and K, as well as calcium, iron, magnesium,
potassium, and zinc. Okra also contains high levels of mucilaginous
fiber. For many years okra has been used as a traditional medicine for
diabetes and for the last few years are also studied in labs. Studies
have been done mostly on diabetic rats, which when treated with seed
powder resulted in decreased blood glucose as okra has the ability
inhibit absorption of glucose in the intestines by blocking
alpha-glucosidase, an enzyme that helps in carbohydrate digestion [18].
One other study, involving humans in Africa showed that consuming okra
as part of a Mediterranean diet, may reduce the risk of blindness in
type 2 diabetics [17].
Mixed berries:
Berries like raspberries, strawberries,
blackberries and blueberries are natural nutritious source of
flavonoids. Darker and riper berries tend to have higher flavonoid value
[20]. Refer the table below for a list of berries and the type of
flavonoid they possess. A study was done to show the beneficial effect
of specific flavonoids on insulin sensitivity. A follow up study on a
large group of men and women free of diabetes, cardiovascular disease,
and cancer at baseline was carried out using dietary intakes of major
flavonoid subclasses. Results proved that higher intakes of anthocyanins
were significantly associated with a lower risk of type-2 diabetes
[19].
Berry fruit
Flavonid type
Blueberries
Quercetin and myricetin
Cranberries
Quercetin and myricetin
Black grapes
Epicatechin and catechin
Blackberries
Epicatechin and catechin
Raspberries
Anthocyanidins and cyanidin
Cherries
Anthocyanidins and cyanidin
Red Grapes
Anthocyanidins and cyanidin
Strawberries
Quercetin, Epicatechin and catechin
Dates:
Date palms (Phoenix dactylifera) are oval
or cylindrical shaped fruit, and are bright red to bright yellow in
color. They are the sweetest and most nutritious of the dry fruits. To
an extent they can be considered as the dessert fruit for the diabetics.
They are packed with nutrition like calcium, iron, phosphorus, sodium,
potassium, magnesium, zinc, thiamin, riboflavin, niacin, folate, vitamin
A, K, natural sugars and fiber. A study was carried out among healthy
subjects and individuals with type-2 diabetes mellitus to study the
effects on postprandial glucose excursions after intake of 5 varieties
of dates. The results showed low glycemic indices for the five types of
dates in all the participants and consumption of dates by diabetic
individuals does not result in significant postprandial glucose
excursions compared to the healthy controls [21].
Cornelian cherry:
Cornelian cherry (Cornus mas L.) is a kind
of berry it has an acidic flavor and best described as a mixture of
cranberry and sour cherry. Well used in making jams and sauces and
traditionally used as an anti-diabetic supplement. A study done,
evaluated the effects of the fruit extract of this plant on biomarkers
of glycemic control in adult patients with type 2 diabetes. The patients
were treated with either the fruit extract or placebo capsules. After 6
weeks of intervention, a significant increase in insulin level, and
decrease in HgbA1C and triglyceride levels were observed in drug group
compared to placebo. This signifies that daily consumption of the fruit
improves glycemic control by increasing insulin level in type 2 diabetic
adult patients [22].
Low fat yogurt/dairy:
The greater health value of low fat diary
product like low-fat milk, cheese and yogurt has been proved with
respect to incidences of many health conditions in comparison to whole
milk and high fat cheese and yogurt. A case-cohort study within the
EPIC-Norfolk Study group was carried out using dairy diet for a week and
their relation to the incidence of risk of type-2 diabetes was
evaluated. Results showed that low fat diary diet especially low fat
yogurt consumption everyday as a part of daily diet decreased the risk
of type 2 diabetes developments in prospective analyses, suggesting that
the consumption of specific dairy types may be beneficial for the
prevention of diabetes [23].
