ArticlePDF Available

Vegetables Consumption and its Benefits on Diabetes

Authors:

Abstract and Figures

Vegetables are indispensable for equilibrated diets since they charge dietary fiber, phytochemicals, vitamins, and minerals. Each vegetable comprise a distinct amalgam and amount of these compounds, which differentiate them from other vegetables. Vegetable intakes has been highly correlated with improved gastrointestinal health, reduced risk of heart attack, some types of cancer and chronic ailments such as diabetes. Type 2 diabetes is a lifestyle ailment. Our vegetables selection and amount of dietary fiber, phytochemicals, vitamins and minerals consumed can either prevent or promote diabetes. This article highlights the nutritional and health benefits of different vegetables and their dietary fiber, vitamin C, vitamin E, carotenoids, flavonoids, thiosulfides, magnesium, selenium, chromium, and zinc contents, to prevent and reverse diabetes. The proper order of eating vegetables before carbohydrate and its effect on postprandial blood glucose levels, and glycemic control is also discussed. Data shows that eating vegetables before carbohydrates is effective to reduce postprandial hyperglycemia in Type 2 diabetes patients, as well as in healthy people. So vegetables should be eaten before carbohydrates at every meal.
Content may be subject to copyright.
Journal of Nutritional Therapeutics, 2017, 6, 1-10 1
E-ISSN: 1929-5634/17 © 2017 Lifescience Global
Vegetables Consumption and its Benefits on Diabetes
João Carlos da Silva Dias1,* and Saeko Imai2
1University of Lisbon - Instituto Superior de Agronomia, Tapada da Ajuda, 1349-017 Lisboa, Portugal
2School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino-shi, Osaka 583-8555, Japan
Abstract: Vegetables are indispensable for equilibrated diets since they charge dietary fiber, phytochemicals, vitamins,
and miner als. Each vegetable comprise a disti nct amalgam and amount of these com pounds, which differentiate them
from other vegetables. Vegetable intakes has been highly corr elated with improved gastrointestinal health, reduced risk
of heart attack , some types of cancer and chronic ailments such as diabetes.
Type 2 diabetes is a lifestyle ailment. Our vegetables selection and amount of dietary fiber, phytochemicals, vitamins and
minerals consumed can either prev ent or promote diabetes. This artic le highlights the nutrition al and health ben efits of
different vegeta bles an d their dietary fiber, vitamin C, vitamin E, carotenoids, flavonoids, thiosulfides, magnesium,
selenium, chromium, and zinc contents, to prevent and reverse diabetes. The proper order of eating vegetables before
carbohydrate and its effect on postprandial blood glucose levels, and glycemic control is also discussed. Data shows that
eating vegetables before carbohydrates is effective to reduce postprandial hyperglycemia in Type 2 diabetes patie nts, as
well as in healthy people. So vegetables should be eaten before carbohydrates at every meal.
Keywords: Vegetables, dietary fiber, phytochemicals, resistant starch, Type 2 diabetes, glucose control, healthier
life.
1. INTRODUCTION
Vegetables play a remarkable role in human
nutrition and health since they charge dietary fiber,
phytochemicals, vitamins, and minerals [1-3].
Until few years ago it was believed that 14 vitamins
and 16 essential minerals were the key for human
nutrition and health. Recently, with the developments in
chemistry, it was found that vegetables contain
thousands of beneficial phytochemicals in addition to
the 14 vitamins and 16 minerals. Some phytochemicals
are robust antioxidants and are believed to reduce the
risk of some chronic ailments [3-7]. Phytochemicals are
the key to best health as well as disease protection and
regression. However, phytochemicals in freshly
harvested vegetables may be thermal degraded and
lost by processing techniques such as long steaming
and cooking [8,9], which reduce their concentration,
and may inactivate hydrolytic enzymes.
Vegetable intake has been highly correlated with
improved gastrointestinal health, and reduced risk of
heart attack, some types of cancer and chronic
ailments such as diabetes [2,3]. By those reasons a
regular consumption of a vegetable rich diet has
unquestionable positive effects on health and is likely
to afford better protection against several chronic
ailments. The mechanisms by which vegetables
*Address correspondenc e to this author at the University of Lisbon - Instituto
Superior de Agronomia, Tapada d a Ajuda, 1349-017 Lisbo a, Portugal;
Tel: 00351.914137940; E-mail: m irjsd@gmail.com
decrease risk of disease is largely unknown [2,3].
Different constituents of the whole food may contribute
to the overall health benefit. For example the dietary
fiber content contribute to the health benefit by
improving bowel transit, by helping manage blood
glucose concentrations, and by transporting through
the human gut a remarkable amount of phytochemicals
and minerals linked to the fiber matrix.
Diabetes (Diabetes mellitus) is a chronic ailment
that arises when the pancreas does not produce
enough insulin or when the body cannot efficaciously
use the insulin (hormone that regulates blood sugar) it
produces. Raised blood sugar (hyperglycemia) is a
common consequence of uncontrolled diabetes [10].
Diabetes are of three main types: Type 1, Type 2, and
gestational diabetes. Type 2 diabetes is the most
common type worldwide. It is a chronic and lifestyle
ailment.
In 2014, about 422 million adults worldwide had
diabetes (that is 1 person in 11) [11], with more than
80% living in the middle- and low-income countries
[12]. Asia alone hosts more than 60%, predominantly
type 2 diabetes [13]. Diabetes prevalence has been
rising for the past 3 decades and will continue rising all
over the world but more speedily in the middle- and
low-income countries [11]. By 2025 a fifth of the world’s
diabetic patients will be Indian [12].
The greatest number of people with diabetes are
between 40-59 years old, with 179 million people
undiagnosed [12]. Diabetes is occurring increasingly in
For Author's Personal Use
2 Journal of Nutritional Therapeutics, 2017, Vol. 6, No. 1 Dias and Imai
children and young adults and, in 2014, many youth
aged under 18 years had diabetes [11].
Our vegetables selection and amount of dietary
fiber, phytochemicals, vitamins, and minerals
consumed can either prevent or promote diabetes [3].
This article highlights the nutritional and health benefits
of different vegetables and the proper level of dietary
fiber, vitamin C, vitamin E, carotenoids, flavonoids,
thiosulfides, magnesium, selenium, chromium, and zinc
contents, that should be consumed to prevent and
reverse diabetes. The proper order of eating
vegetables before carbohydrate and its effect on
postprandial blood glucose levels, and glycemic control
is also discussed.
2. VEGETABLES AND NUTRITIONAL AND HEALTH
BENEFITS
A world survey showed that at least 402 vegetables
are cultivated and commercialized worldwide [14,15].
They represent 69 families and 230 genera. From
these great diversity leafy vegetables comprised 53%
of the total, followed by fruits vegetable (15%), and
roots and tuber vegetables (17%).
All the vegetables may provide defense to humans
against chronic ailments. And there is a general
sentiment among nutritionists that the nutrition and
health benefit of vegetables should not be connected to
only one form of vegetable. A balanced diet that
includes more than one form of vegetable is liable to
provide better nutrition and health protection, since it
will ensure an adequate intake of dietary fiber,
phytochemicals, vitamins, and minerals [3,16,17].
With the exclusion of glucosinolates and thiosulfides
(which are distinct phytochemicals of cruciferous and
alliums, respectively), the phytochemicals, vitamins,
and minerals content of a many vegetables lie
principally in dietary fiber, folate, polyphenols
(carotenoids, flavonoids), vitamin C, and selenium
[2,3]. The principal dissimilarity is that each vegetable
family incorporate a distinct amalgam and amount of
these bioactive compounds, which differentiate them
from other vegetables [2,17]. For instance vegetables
of the Apiaceae family (carrot, parsnip, celery, celeriac,
fennel, parsley, coriander, etc.) are rich in flavonoids,
carotenoids, vitamin C, and vitamin E. The vegetables
of the Asteraceae or Compositae family (lettuce,
chicory, stem lettuce, globe artichoke, etc.) are rich in
flavonoids, tocopherols and conjugated quercetin. The
Chenopodiaceae family vegetables (Swiss chard,
spinach, garden beet, quinoa, etc.) are among those
that are rich in oxalates [18,19], but also excellent
sources of dietary fiber, vitamins, calcium, manganese,
flavonoids and carotenoids. The Cucurbitaceae family
vegetables (e.g. squash, pumpkin, cucumber, melon,
bitter gourd, etc.) are rich in carothenoids, tocopherols,
and vitamin C [20]. All the legumes (Leguminosae or
Fabaceae family; e.g. pea, bean, soy-bean, lentils,
chickpea, etc.), mature and immature seeds are great
sources of dietary fiber, resistant starch, protein,
isoflavonoids [21], calcium and iron. Cruciferous
vegetables (Cruciferae or Brassicaceae family) which
include kales, collards, cabbages, Brussels sprouts,
cauliflower, broccoli, kailan, Pak choi or Bok choi,
Chinese cabbage, turnip, swede, watercress, radish,
rocket, watercress, mustards, etc. are high sources of
glucosinolates, as well as vitamin C, carotenoids,
calcium, and can accumulate selenium. The vegetables
of the Alliaceae family (onions, garlic, shallots, leek,
Welsh onion, chives, etc.) are rich in thiosulfides,
flavonoids, calcium, potassium, manganese, chromium
and can accumulate selenium. Vegetables of the
Solanaceae family that includes tomato, potato, sweet
and hot peppers, eggplant, etc. are very diverse, in
their contribution to bioactive compounds.
3. DIABETES
3.1. Types
As mentioned earlier diabetes are of three main
types: Type 1, Type 2, and gestational.
Type 1 diabetes, named as juvenile or insulin-
dependent diabetes, is differentiated by its deficiency in
insulin production and demands daily administration of
insulin, typically by injection. The cause of Type 1
diabetes is actually not perfectly known and it is not
preventable. Today we only know that the damage of
the insulin-producing cells occur due to the cells of the
body's immune system that instead of protecting they
attacked the cells of the pancreas destroying its ability
to produce insulin. Nevertheless new research has
revealed that diet and lifestyle can dramatically
decrease the risk of Type 1 diabetes and their
complications [22].
Type 2 diabetes, named as adult or non-insulin-
dependent diabetes, is due to the body’s ineffective
use of insulin. Body produces insulin but cannot
effectively use it. Type 2 is the most prevalent in the
world (about 9 out 10 people with diabetes have type 2
diabetes). Reports of Type 2 diabetes in children that
were previously rare, have increased worldwide.
For Author's Personal Use
Vegetables Consum ption and its Benefits on Diabetes Journal of Nutritional Therapeutics, 201 7, Vol. 6, No. 1 3
Gestational diabetes is different from previous ones
and it is characterized by hyperglycemia only during
pregnancy [23]. Women with gestational diabetes have
increased risk of Type 2 diabetes in the future.
Diabetes is a major cause of blindness and vision
loss [24], kidney failure [25], heart attacks and strokes
[26], leg amputation and nerve damage [11],
Alzheimer's disease and dementia [27-30]. In 2014,
diabetes was the direct cause of 1.5 million deaths.
WHO projects that diabetes will be the 7th major cause
of death in 2030 [12].
Typical Type 2 diabetes is caused by unhealthy diet
and physical inactivity, which leads to overweight or
obesity. Higher body circumference and Body Mass
Index (BMI) are usually correlated with increased risk
of type 2 diabetes, although this relationship may vary
in different populations [11]. For instance Asians
develop diabetes at lower degrees of obesity and at
younger ages. Asians are known to have more fat per
BMI unit which contributes to increased insulin
resistance [13]. Among the 3 major Asian populations,
Indians have substantially higher level of insulin
resistance, followed by intermediate levels in Malays,
and the lowest level in Chinese population (p<0.001)
[13]. Over a fifth of China’s adult population is
overweight.
3.2. Diabetes Tests and Screening
The three main diabetes tests and screenings are:
blood glucose, hemoglobin A1c, and Continuous
Glucose Monitoring system (CGMs).
The blood glucose test determines the amount of
glucose in a sample of blood. The blood glucose test
may be used to monitor glucose levels and to detect
hyperglycemia and hypoglycemia, in people diagnosed
with diabetes. The test is usually done after fasting (not
eating anything for at least 8 hours) but can be done at
any time of the day. It is carried out using a blood
sample taken from a finger or from the arm. In the
market there are blood glucose meters that allow
people to do their blood glucose tests at home. It
involves pricking the side of a finger with a finger-
pricking device and putting a drop of blood on a testing
strip.
The fasting blood glucose level values for a normal
person without diabetes is 70 to 108 mg/dl (= 3.9 to 6
mmol/l); for a pre-diabetic is 108 to 125 mg/dl (= 6 to 7
mmol/l); and for a diabetic patient is higher than 125
mg/dl (> 7 mmol/l). Blood sugar levels for those without
diabetes should be below 7 mmol/L (125 mg/dl).
The hemoglobin A1c test (HbA1c) is a better test
than blood glucose, that shows how well the diabetes is
being disciplined. It measures the amount of glucose
that is being carried by the red blood cells/hemoglobin.
Measuring HbA1c physicians are able to get a general
panorama of what the average blood sugar levels have
been over a 3 months period.
For people without diabetes, the normal range for
the hemoglobin A1c test is between 4% and 5.7% (=
20 to 40 mmol/mol). Hemoglobin A1c levels between
5.7% and 6.4% (= 40 to 45 mmol/mol) indicate
increased risk of diabetes (pre-diabetes), and levels
higher than 6.4% (> 45 mmol/mol) indicate diabetes.
The aim for patients with diabetes is to have
hemoglobin A1c levels less than 7%.
CGMs is a device that uses a tiny sensor placed
under the skin of the belly of the patient. It measures
the amount of glucose in the fluid inside the body. A
transmitter on the sensor then sends the information to
a wireless-pager-like monitor that the patient can for
example clip on its belt. The sensor continuously
checks the glucose levels whether they are highs or
lows. Glucose reading is done every 5 minutes. It
tracks the glucose levels throughout the day displaying
for instance the effect of foods and exercise on glucose
levels. So a CGMs is able of detecting hypoglycaemia
and hyperglycaemia that may be undetected by self-
monitoring blood glucose and HbA1c tests [31].
4. VEGETABLES AND DIABETES
4.1. Vegetable Bioactive Compounds
The vegetable bioactive compounds usually
associated to the reduction or reversion of Type 2
diabetes are dietary fiber, resistant starch, vitamins C
and E, carotenoids, flavonoids, thiosulfides,
magnesium, selenium, chromium, and zinc.
Dietary fiber is very important since it works to keep
blood-sugar levels stable and transport through the
human gut an important amount of carotenoids and
polyphenols coupled to the fiber matrix [2,3]. Dietary
fiber is grouped into soluble and insoluble fiber. Soluble
fiber retards gastric emptying, slows the glucose
absorption, and is entirely or partly fermentable in the
large intestine [32]. Soluble fiber it is very important for
diabetics, as it slows the glucose absorption [2,3].
Insoluble fiber is important too, and health benefits
For Author's Personal Use
4 Journal of Nutritional Therapeutics, 2017, Vol. 6, No. 1 Dias and Imai
include shortening of the bowel transit time and softer
feces.
Resistant starch is the starch that it is resistant to
stomach acid and digestive enzymes. It escapes
digestion in the small intestine but passes to the large
intestine, where it goes through fermentation by
bacteria in the colon. It acts like a fiber too. It supplies
few calories, and most of the calories do not raise
glucose levels. When the bacteria in the bowel degrade
the resistant starch it forms new compounds that have
health benefits and beneficial effects for diabetics
[3,17,22].
Eating vegetables with dietary fiber and resistant
starch will reduce hunger and appetite and for diabetics
it is critical for lowering insulin requirement for starch
digestion.
Vitamins C and E have been inversely associated
with diabetes since they are antioxidants that
overcompensate the endothelial dysfunction and
glutathione level to normalize blood glucose pressure
that occurred in diabetic patients with hyperglycemia
[3,17].
Carotenoids such as α- and β-carotene, lycopene,
lutein, zeaxanthin, and β-cryptoxanthin, have a
protective effect against progress of diabetes by
relieving oxidative stress that interferes with the
glucose uptake by cells [3,17].
Flavonoids such as anthocyanins, flavonols,
flavones, isoflavonoids, and syringic acid are
associated with diabetes since their intake was
observed to reduced type 2 diabetes risk.
Thiosulfides decrease blood glucose level by
stimulating insulin secretion by the pancreas.
Magnesium is important since insulin secretion and
function requires magnesium. It helps to regulate blood
sugar. It is also the relaxation mineral.
Selenium is also important, but high selenium levels
may contribute to diabetes [3,17].
Chromium is an insulin cofactor that helps insulin
work better, since it helps the hormone escort glucose
from the blood-stream into cells. Diabetic-promoting
diets are low in chromium. Eating refined grains,
sweets, and processed foods leads to chromium
deficiency and worsens diabetes.
Zinc is necessary for the production of insulin which
regulates blood sugar levels and interacts also with
other nutrients [3,17].
4.2. ANDI and Vegetables with Anti-Diabetic
Properties
ANDI (Aggregate Nutrient Density Index) is a
scoring system based on nutrient content, rated on a 1-
1,000 scale, that was established by Dr. Fuhrman [33].
This index are scores attributed to a variety of
vegetables (and other foods) based on how many
nutrients they deliver to our body in each calorie
consumed. It was calculated by evaluating the content
of dietary fiber, vitamins, minerals, phytochemicals,
antioxidant capacities, etc. It is an index that estimates
the nutritional quality of vegetables. It guides on
increasing the nutrient density of the diet. The higher
the ANDI score, and the greater percentage of those
vegetables in the diet, the better our health and the
probability of reversing the diabetes. Table 1 presents
the highest ANDI scores in green vegetables.
Three main vegetable families are shown in this
table: Brassicaceae (kale, collard greens, mustard
Table 1: List of Identified Green Vegetables with High ANDI Scores
Vegetable
ANDI
Vegetable
ANDI
1. Kale
1000
9. Chinese cabbage
714
2. Collar d greens
1000
10. Brussels sprouts
672
3. Mustard gree ns
1000
11. Arug ula/Rocket
604
4. Swiss chard
1000
12. Lettuce, gr een lea f
585
5. Turni p greens
1000
13. Chicory
516
6. Waterc ress
1000
14. Romaine let tuce
510
7. Bok choi/Pak choi
865
15. Cabbage
481
8. Spinach
739
16. Broccoli rabe
455
For Author's Personal Use
Vegetables Consum ption and its Benefits on Diabetes Journal of Nutritional Therapeutics, 201 7, Vol. 6, No. 1 5
greens, turnip greens, watercress, pak choy, Chinese
cabbage, Brussels sprouts, rocket, cabbage and
broccoli rabe), Chenopodiaceae (Swiss chard and
spinach) and Asteraceae (green leaf lettuce, chicory
and Romaine lettuce). The highest ANDI scores of non-
green vegetables are presented in Table 2.
Table 2 also shows other Brassicaceae like radish,
turnip, kohlrabi, cauliflower, and rutabaga. Different
vegetables from various families are also shown as
well as differences among the peppers, where orange
pepper is better than the red and red better than the
green pepper.
Leafy vegetables thus have the highest ANDI
scores compared to other vegetables. They are high-
nutrient and low glycemic load vegetables. Leafy
vegetables are rich in dietary fiber, carotenoids, vitamin
C, vitamin E, flavonoids, calcium, magnesium, etc. All
the leafy-green vegetables are good sources of
magnesium because they have chlorophyll. An actual
meta-analysis set up that greater leafy-green
vegetables consumption was correlated to 14%
decrease in risk of Type 2 diabetes [34]. An earlier
research reported that each daily serving of leafy-green
vegetables generates a 9% decrease in risk of Type 2
diabetes [35].
The leafy vegetables with high ANDI scores are
Brassicaceae. They have dietary fiber and are a rich
source of glucosinolates and other phytonutrients, and
have a very high content in calcium and β-carotene.
They are excellent sources of lutein and can also
accumulate selenium.
Khan et al. [36] showed that oral feeding of regular
rats for 60 days with a B. juncea diet (10% w/w) led to
significant hypoglycemic effect. This result was
associated to the positive stimulation of glycogen
synthetase and to the suppression of glycogen
phosphorylase and some other gluconeogenic
enzymes.
Another important family is Chenopodiaceae. A
recent research has shown that Swiss chard leaves
contain at least 13 distinct polyphenol antioxidants [37]
comprising the flavonoids kaempferol and syringic acid
that have blood sugar regulating properties [37-39].
Syringic acid was demonstrated to inhibit the activity of
the enzyme α-glucosidase. When α-glucosidase gets
inhibited, fewer carbohydrates are converted to sugars
and blood sugar is able to remain more steady [40].
Beet leaves have the same properties, since beet and
Swiss chard are both from the Chenopodiaceae family,
and are a unique source of the bioactive antioxidants
named betalains. Nine betacyanin pigments where
identified in the reddish-purple stems and veins of the
leaves of Swiss chard and beet [41]. In the Swiss
chard's yellowish stems and veins 19 betaxantin
pigments, including histamine-betaxantin, alanine-
betaxantine, tyramine-betaxantine, and 3-
methoxytyramine-betaxantin were identified [41].
Yoshikawa et al. [42], in an oral glucose tolerance test
(OGTT) conducted in rats, that measures the body’s
ability to metabolize glucose [43], observed that several
glycosides isolated from the root extract of beet
increase glucose tolerance.
In Asteracea, lettuces and chicories are the main
vegetables used in raw salads. Leaf and Romain
lettuces have higher ANDI scores (585 and 510
respectively) than iceberg lettuce (127). Besides the
nutritive and diabetic value of leaf and Romaine lettuce
are higher than head lettuces (butter and batavia).
They have more dietary fiber, minerals, vitamins, and
phytochemicals. Raw vegetables are the healthiest
food we can eat since some phytochemicals are only
available if we eat the vegetables raw.
In the non-green vegetables we have after radish
and turnip (both Brassicaceae) the carrots. Carrots are
not a negative vegetable, even for the diabetic,
because they are low in calories, nutrient rich, have
fiber, and their glycemic load (GL) is only 3. Carrots
Table 2: List of Non-Green Vegetables with High ANDI Scores
Vegetable
ANDI
ANDI
1. Radish
502
315
2. Turni p
473
296
3. Carrots
458
265
4. Acorn/ Winter squash
444
258
5. Bell p epper, Yellow /Orange
371
244
6. Kohlra bi
352
234
For Author's Personal Use
6 Journal of Nutritional Therapeutics, 2017, Vol. 6, No. 1 Dias and Imai
when they are eaten raw their glycemic effect is
lessened further as the body does not absorb all of the
calories in the raw food. Recent research advocate that
orange carrot with α- and β-carotene (vitamin A-rich
carotenoids) might help diabetics [44,45]. Purple
carrots, rich in anthocyanins (flavonoids) and low in
carotenoids, were also recently associated with
reduction in impaired glucose tolerance [46].
Another important non-green vegetable is potato. In
general, potato is only associated as a source of
carbohydrates. But it is also an excellent source of
essential amino acids (such as lysine) and other
bioactive compounds. In addition to superior quality
proteins, potato tubers also have significant amounts of
vitamins and minerals, as well as phytochemicals
(phenolics, phytoalexins, etc.), and protease inhibitors
[2]. There are yellow, red, and purple fleshed potato
varieties with high content of phytochemicals though
some varieties are known to have lower levels [1-3].
Other bioactive antioxidants presented in potato tubers
include α-tocopherol, lutein, β-carotene, folates and
selenium [2].
A good alternative to potato for diabetic patients are
kohlrabi and rutabaga which are of the Brassicaceae
family. They are not starchy as potato, and have higher
ANDI scores. Both can be eaten raw and when sliced
they do not produce discoloration (no oxidation as in
potato).
Other two families very important for diabetics are
Alliaceae, Curcubitaceae and Leguminosae since they
include several vegetables with anti-diabetic properties.
Consumption of Alliaceae are necessary of a
diabetes prevention (or reversal). Garlic lowers blood
sugar levels in diabetic patients [47] and administration
of S-methyl cysteine sulfoxide isolated from onion
restrained blood glucose and showed significant
hypoglycemic effect in rats [2,17]. Onions and other
Alliaceae also contain chromium that is linked to
diabetes prevention by enhancing insulin receptor
kinases [48]. Clinical surveys on diabetic patients
showed that chromium can decrease fasting glucose,
ameliorate glucose tolerance and bring down insulin
levels. Swamy et al. [47] observed in some varieties
that 200 g of onions contain chromium up to 20% of the
daily requirements.
For Curcubitaceae, bitter gourd (Momordica
charantia) has been intensively studied for its anti-
diabetic attributes. Different studies reported
hypoglycemic and anti-hyperglycemic properties of
bitter gourd [47,49-51]. Clinical surveys on diabetic
patients using pulp and juice extracts of bitter gourd
were reported to bring down serum insulin levels, to
lower fasting blood glucose levels, and to ameliorate
glucose tolerance [52]. Vicine, charantin and
polypeptide-p are the principal hypoglycemic bioactive
compounds from bitter gourd [53]. But there are also
carotenoids (β-carotene, lutein, and zeaxanthin),
triterpenoids (momordicin), alkaloids and saponins,
responsible for their side effect on glycemic control
[54]. Momordicin possess insulin-like activity [55].
Besides bitter gourd other non-sweet Curcubitaceae
that have anti-diabetic properties are ivy gourd
(Coccinia grandis), snake gourd (Trichosantes
cucumerina), and ridge gourd (Luffa acutangula).
Immature fruits of ivy gourd have anti-hyperglycemic
properties since they help regulate blood sugar levels
[56]. In India they are used to prevent or treat diabetes
[56]. Bioactive compounds in the ivy gourd inhibit
glucose-6-phosphatase [47], a liver enzyme involved in
the regulation of sugar metabolism. Snake gourd is
also considered to be useful in treating Type 2 diabetes
[47]. Ridge gourd contain insulin like peptides, and
alkaloids that help to lower fasting blood glucose levels
[47,50].
In Leguminosae consumption of the legumes is
correlated to reduced risk of Type 2 diabetes since they
are the ideal carbohydrate source [3,33,57]. They are
low in GL due to their moderate protein and abundant
dietary fiber and resistant starch (that is fermented by
bacteria in the colon). The chemical composition of
legumes show decreases in calories that can be
absorbed which contribute to the control of blood sugar
levels.
5. EFFECT OF EATING VEGETABLES BEFORE
CARBOHYDRATES ON GLYCEMIA
Figure 1 shows a Continuous Glucose Monitoring
(CGM) data, of one patient with Type 2 diabetes (T2D),
after eating carbohydrates before vegetables and after
eating the reverse regimen. When the patient ate
carbohydrates before vegetables, we can see values of
the postprandial hyperglycemia of 360, 320, and 340
mg/dl; and also hypoglycemia before the meal. When
the patient ate vegetables before carbohydrates,
postprandial hyperglycemia was decreased, and no
hypoglycemia was observed.
Imai et al. [58] studied whether eating vegetables
before carbohydrates could reduce the daily
For Author's Personal Use
Vegetables Consum ption and its Benefits on Diabetes Journal of Nutritional Therapeutics, 201 7, Vol. 6, No. 1 7
postprandial glucose excursions measured by a CGM
system in 19 Japanese outpatients with T2D
(HbA1c=7.2 ± 1.0%; and Fasting Blood Glucose
(FBG)=8.06±2.67 mM/l) and 21 participants with
Normal Glucose Tolerance (NGT); normal persons
without diabetes (HbA1c=5.4±0.6%; and
FBG=4.89±0.50 mM/l). All these 40 subjects (in a
randomized design) were allotted to a CGM system for
72 hours and eating test vegetable meals before and
after carbohydrates meals on the second and third day.
The test meals, that possessed 21 grams of dietary
fiber and 125.6 kJ.kg1 per day, consisted of 500 grams
of vegetables, meat or fish as the main dish, and rice or
bread as carbohydrates.
Figure 2 presents the mean of the daily glucose
values in the 19 outpatients with T2D and the 21
participants with NGT after eating carbohydrates before
vegetables, and after the vegetable meal. The results
show a significantly reduction in glucose profile when
the subjects ate vegetables before carbohydrates
Figure 1: CGM data of a patient with Type 2 diabetes (T2D) after eating carbohydrates before vegetables and the reverse
regimen.
Figure 2: Effect of eating vegetables before carbohydrates on glucose concentration of 19 outpatients with T2D and 21 NGT
participants. Mean of the daily glucose values in the T2D outpatients and in the NGT participants after eating carbohydrates
before vegetables, and the reverse regimen.
For Author's Personal Use
8 Journal of Nutritional Therapeutics, 2017, Vol. 6, No. 1 Dias and Imai
compared to when it was consumed after in patients
with T2D and NGT participants.
In another research, only with outpatients with T2D,
Imai et al. [59] examined if instructing these diabetic
patients to eat vegetables before carbohydrates was
effective on a long-run screening (30 months) of
glycemic control (Figure 3). They examined changes in
HbA1c (NGSP-%) in outpatients with T2D as the main
outcome. A total of 333 patients were distributed into
two study groups: one educational (n=196) that
received operating instructions and a brochure about
eating vegetables before carbohydrates; and a control
(n=137) who received only a checkup by a physician.
Improvements in HbA1c levels over 30 months were
maintained from 8.6 to 7.5% (NGSP%) with the
educational group (p < 0.001) while no modifications
were observed with the control (8.2 to 8.1%), and
HbA1c levels in the educational were significantly lower
than the control after 3 to 30 months of the survey
[58,60].
The main reason for the decrease of postprandial
blood glucose levels by eating vegetables before
carbohydrates was due to consumption of dietary fiber
present in the vegetables which allows carbohydrates
consumed after vegetables to be digested slowly and
so requiring less insulin [61]. Besides vegetables
consumed before might have stimulate gastrointestinal
incretin hormones (glucagon-like peptide-1 and
glucose-dependent insulinotropic polypeptide).
secretion, which contributes to the reduction in
glycemic values [62], because they release insulin from
the pancreas after carbohydrate ingestion and so they
are essential in maintaining normal levels of glucose in
the blood.
6. CONCLUSIONS
All the vegetables may provide protection to
humans against chronic ailments. A balanced diet that
incorporates a diversity of vegetable is likely to offer
better protection to diabetes since each vegetable
contains a distinct amalgam of phytochemicals,
vitamins, and minerals.
Increased consumption of all leafy-green vegetables
is associated to a decrease risk of Type 2 diabetes
since they have dietary fiber and they offer many
phytochemicals, vitamins and minerals to our body.
Other non-green and non-starchy vegetables that are
also rich in dietary fiber, and bioactive compounds also
keep blood glucose low. Raw vegetable salads should
be eaten in large quantities at the beginning of each
main meal. Raw vegetables are better anti-diabetic
foods than the cooked or processed since
phytochemicals may be degraded by cooking and long
steaming, due to thermal degradation and inactivation
of the hydrolytic enzymes.
Both starchy and non-starchy vegetables are
important for our diet. Legumes are a good
carbohydrate source due to their protein, dietary fiber
and resistant starch content. Vegetable fruits rich in
fiber and antioxidants are also excellent vegetables for
diabetics if sugar levels are low. Some cucurbits like
bitter gourd, ivy gourd, snake gourd, and ridge gourd
Figure 3: Effect of eating vegetables before carbohydrates on long-run screening of glycemic control. Study carried out during
30 months (2,5 years) in two study groups of outpatients with T2D: educational (n=196), eating vegetables before
carbohydrates, and the control. It was evaluated variance in HbA1c (NGSP %). Baseline vs. after intervention (months): ***=
p0.001. Educational (Veg. before carbo.) vs. the control group: =p0.05, ###= p0.001.
For Author's Personal Use
Vegetables Consum ption and its Benefits on Diabetes Journal of Nutritional Therapeutics, 201 7, Vol. 6, No. 1 9
are recommended and considered useful for Type 2
diabetes.
Consuming vegetables before carbohydrates is
effective to reduce postprandial hyperglycemia (and
less hypoglycemia) in Type 2 diabetes patients. So
Type 2 diabetes patients should eat vegetables before
carbohydrates. This recommendation is also applicable
to healthy people in order to prevent the onset of
diabetes. Eating vegetables before carbohydrates is
therefore the new concept instead of encouraging
carbohydrate restrictions.
REFERENCES
[1] Dias JS, Ryder E. World vegetable industry: production,
breeding, trends . Hort Rev 2011; 3 8: 299-35 6.
[2] Dias JS. Major classes of phytonutriceuticals in vegetables
and health benefits: A Review J Nutr Therap 2012 ; 1: 31-62.
[3] Dias JS. 1. Vegetable breeding for nutritional quality and
health benefits. In: Carbone K, editor. C ultivar: chemical
properti es, antioxida nt activities and health b enefits. Nov a
Science Publishers, Inc., Hauppauge, New York. 2012; p. 1-
81.
[4] Craig W, Beck L. Phytochemicals: health protective effects.
Can J Diet Pract Res 1999; 60: 78-84.
[5] Herrera E, Jimenez R, Aruoma O I, et al. Aspects of
antioxida nt foods and supplements in health and disease.
Nutr Rev 2009; 67(1): S140-S144.
https://doi.org/ 10.1111/j.1753-4887.2009.00177.x
[6] Wargovich MJ. Anticancer properties of fruits and
vegetables. HortScience 2000; 35: 573-575.
[7] Southon S. Increased fruit and vegetable consumption within
the EU: Potential health benefits. Food Res Int 2000; 33:
211-217.
https://doi.org/ 10.1016/S0963-9969(00)00036 -3
[8] Verkerk R, Knol JJ, Dekker M. The effect of steaming on the
glucosinolate content in broccoli. Acta H ort 20 10; 867 : 37-45.
https://doi.org/ 10.17660/ActaHortic.2010.867.3
[9] Palermo M, Pellegrini N, Fogliano V. The effect of cooking on
the phytochemical content of vegetables. J Sci Food Agric
2014; 94(6): 1057-1070.
https://doi.org/ 10.1002/jsfa.6478
[10] WHO (World Health Organization). Definition, diagnosis and
classification of Diabetes mellitus and its complications. Part
1: Diagnosis and class ificati on of Diabetes mellitus. World
Health Organization, Report Number: WHO/NCD/NCS/99.2.
WHO, Geneva; 1999.
[11] WHO (World Health Organization). Global report on diabetes.
WHO, Geneva; 2016.
[12] Hoang TD. Prevalence of diabetes mellitus in the world and
updates of diabetes care 2015. BIT's 4th Annual World
Congress of Diabetes-2015, Ka ohsiung, Taiwan 2015; p.
220.
[13] Baruah MP. Type 2 diabetes in Asia population: regional
similarities, differences and challenges in patient care. BIT's
4th Annual World C ongress of Diabetes-2015, Kaohs iung,
Taiwan 2015; p. 222.
[14] Kays SJ, Dias JS. Common names of commercially
cultivated vegetables of the world in 15 languages. Economic
Botany 1995; 49(2): 115-152.
https://doi.org/ 10.1007/BF02862917
[15] Kays SJ. Cultivated Vegetables of the World: A Multi-lingual
Onomasticon. Wageningen Academic Publishers, The
Netherlands; 2011.
[16] Dias JS. Plant breeding for harmony between modern
agriculture production a nd the environment. Agricultural
Sciences 2015; 6: 87-116.
https://doi.org/ 10.4236/as.2015.61008
[17] Dias JS. Nutritional quality and health benefits of vegetables:
a review. Food Nutr Sci 2012; 3: 1354-1374.
https://doi.org/ 10.4236/fns.2012.310179
[18] Prakash D, Nath P, Pal M. Composition, variation of
nutritional contents in leav es, seed protein, fat and fatty acid
profile of Chenopodium species. J Sci Food Agric 1993;
62(2): 20 3-205.
https://doi.org/ 10.1002/jsfa.2740620214
[19] Sienera R. Oxalate contents of species of the Polygonaceae,
Amaranthaceae and Chenopodiaceae families. Food Chem
2006; 98(2): 220-224.
https://doi.org/ 10.1016/j.foodchem.2005.05.059
[20] Dhillon NPS, Monforte AJ, Pitrat M, et al. Melon landraces of
India: contributions and importance. Plant B reed Rev 2012;
35: 85-150.
[21] Misra SK. Anti-nutritive bioactive compounds present in
unconventional pulses and legumes. Res J Ph arm Biol Chem
Sci 2012; 3: 586-597.
[22] Barnard ND. Dr. Neal Barnard's Program for Reversing
Diabetes. Rodale Inc., New York; 2007.
[23] WHO (World Health Organization). Diagnostic criteria and
classification of hyperglycaemia first detected in pregnancy.
World Health Organization, Report Number:
WHO/NMH/MND/13.2. WHO, Geneva; 2013.
[24] Bourne RR, Stevens GA, White RA, et al. Caus es of vision
loss worldwid e, 1990-2010: a systematic analysis. L ancet
Global Health 2013; 1: e339-e349.
https://doi.org/ 10.1016/S2214-109X(13 )70113-X
[25] Bethesda MD. 2014 USRD S annual data report:
Epidemiology of kidney disease in the United States. United
States Renal Data System. National Institutes of Health,
National Institute of D iabetes and Digestive and Kidney
Diseases 2014; p. 188-210.
[26] Sarwar N, Gao P, Seshasai SR, et al. Diabetes mellitus,
fasting blood glucose concentration, and risk of vascular
disease: a colla borativ e meta-analys is of 102 prospective
studies. Emerging Risk Factors Collaboration. Lancet 2010;
26,375: 2215-2222.
[27] Humpel C. Chronic mild cerebrovascular dysfunction as a
cause for Alzheimer's disease. Rev Exp Gerontol 2011; 46:
225-232.
https://doi.org/ 10.1016/j.exger.2010.11.032
[28] Humpel C. Editorial to the special issue "Vascular dementia".
Rev Exp Gerontol 2012; 47: 1.
https://doi.org/ 10.1016/j.exger.2012.10.001
[29] Mont e SM. Type 3 diabetes is sporadic Alzheimer 's disease:
mini-review. Eur Neuropsychoparmacol 2014; 24: 1954-
1060.
https://doi.org/ 10.1016/j.euroneur o.2014. 06.008
[30] Heneka MT, Fink A and Doblhammer G. Effect of
pioglitazone medicat ion on the incidenc e of dement ia. Annals
Neurol 2015; 78: 284-294.
https://doi.org/ 10.1002/ana.24439
[31] Klonoff DC. Continuous glucose monitoring: roadmap for
21st ce ntury diabet es therapy. Diab etes C are 2005; 28:
1231-1239.
https://doi.org/10.2337/diacare.28.5.1231
[32] Anderson JW, Deakins DA, Floore T L, et al. Dietary fiber and
coronary heart disease. Crit Rev Food Sci Nutr 1990; 29: 95-
147.
https://doi.org/ 10.1080/1040839900 952751 8
[33] Fuhrman J. The End of Diabetes: The Eat to Live Plan to
Prevent and Reverse Diabetes. Harper Collins Publishers,
New York; 2013.
For Author's Personal Use
10 Journal of Nutritional Therapeutics, 2017, Vol. 6, No. 1 Dias and Imai
[34] Carter P, Gray LJ, Troughton J, et al. Fruit and vegetable
intake and incidence of type 2 diabetes mellitus: systematic
review and meta-analysis. BMJ 2010; 341: c4229.
[35] Bazzano LA, Li TY, Joshipura KJ, et al. Intake of fruit,
vegetables and fruit juices and risk of diabetes in women.
Diabetes Care 2008; 31: 1311-1317.
https://doi.org/10.2337/dc08-0080
[36] Khan BA, Abraham A, Leelamma S. Hypoglycemic action of
Murraya Koeingii (curry leaf) and Brassica juncea (mustard):
mechanism of action. Ind J Bioc hem Biophys 1995; 32: 106-
108.
[37] Pyoa YH, Lee TC, Logendrac L, et al. Antioxidant activity and
phenolic compo unds of Swiss chard ( Beta vulgaris
subspecies cycla) extracts. Food Chem 2004; 85: 19-26.
https://doi.org/ 10.1016/S0308-8146(03)00294 -2
[38] Bolkent S, Yanarda R, Tabakolu-Ouz A, et al. Effects of
chard (Beta vulgaris L. var. cicla) extract on pancreatic B
cells in streptozotocin-diabetic rats: a morphological and
biochemic al study. J Ethnop harmac ol 2000 ; 73: 251-259.
https://doi.org/ 10.1016/S0378-8741(00)00328 -7
[39] Mateljan G. The World's healthiest foods. George Matel jan
Foundation, G lendale, C alifornia; 2016.
[40] Tundis R, Loizzo MR, Menichini F. Natural products as
alpha-amylase and alpha-glucosidas e inhibitors and their
hypoglycaemic potential in the treatment of diabetes: an
update. Mini Rev Med Chem 2010; 10: 315-331.
https://doi.org/ 10.2174/1389557107 91331007
[41] Kugler F, Stintzing FC, Carle R. Identification of betalains
from petioles of differently colored Swiss chard (Beta vulgaris
L. ssp. cicla [L.] Alef. Cv. Bright Lights) by high-performance
liquid chromatography-electrospray ion. J Agric Food Chem
2004; 52: 2975-2981.
https://doi.org/ 10.1021/jf035491w
[42] Yoshikawa M, Murakami T, Kadoya M, et al. Medicina l
foodstuff I II. Sugar beet. Hypoglicemic oleanolic acid
oligoglycosides, betavulgarosides I, II, III, and IV from the
root of Beta vulgaris L. (Chenopodiaceae). Chem
Pharmaceut Bull 1996; 44: 1212-1217.
https://doi.org/ 10.1248/cpb.44.1212
[43] ADA (American Diabetes Association). Standards of Care.
Diabetes Care 2016; 39 (Suppl. 1): S1S119.
[44] Dias JS. Nutritional and health benefits of carrots and their
seed extracts. Food Nutr Sci 2014; 5: 2147-2156.
https://doi.org/ 10.4236/fns.2014.522227
[45] Coyne T, Ibiebele TI, Baade PD, et al. Diabetes Mellitus and
serum carotenoids: findings of a population-based study in
Queensland, Australia. Amer J Clinical Nutr 2005; 82: 685-
693.
[46] Poudyal H, Panchal S, Brown L. Comparison of purple carrot
juice and β-carotene in a high-carbohydrate, high-fat diet-fed
rat model of the metabolic syndrome. British J Nutr 2010;
104: 1322-1332.
https://doi.org/10.1017/S0007114510002308
[47] Swamy KRM, Nath P, Ahuja KG. 9. Vegetables for human
nutrition and health. In: Nath P, editor. The Basics of Human
Civilization-Food, Agric ulture and Humanity, Volume-II-Food.
Prem Nath Agricultural Science Foundation (PNASF),
Bangalore & New India Publishing Agency (NIPA), New
Delhi, India 2013. p. 145-198.
[48] Wang H, Kruszewki A, Brautigan DL. Cellular chromium
activation of insulin receptor kinase. Biochemistry 2005; 44:
8167-8175.
https://doi.org/ 10.1021/bi0473152
[49] Chen Q, Chan LLY, Li ETS. Bitter melon (Mo mordica
charantia) reduces adiposity, lowers serum insulin and
normalizes glucose t oleranc e in rats fed a hi gh fat diet. J Nutr
2003; 133: 1088-1093.
[50] Patil B, J ayaprakasha GK and Vikram A. Indigenous crops of
Asia and Southeast Asia: exploring health-promoting
properti es. HortScience 2012; 47: 821-827.
[51] Chao PM. One more support for recruiting bitter melon in
therapeutic diet for diabetes and its comorbidity management
- bitter melon ameliorates hepatic steatosis related with
hyperglyc emia. BIT's 4th Annual World Congress of Dia betes
- 2015, Kaohsiung, Taiwan. 2015; p. 236.
[52] Ahmad N, Hassan M, Halder H, Bennoor K. E ffect of
Momord ica char antia (Karolla) extracts on fasting and
postprandial serum glucose levels in NIDDM patients.
Bangladesh Med Res Counc Bull 1999; 25:11.
[53] Yeh G, Eisenberg D, Kaptchuk T, Phillips R. Systematic
review of herbs and dietary supplements for glycemic control
in diabet es. Diabetes Care 2003; 26: 1277.
https://doi.org/ 10.2337/diac are.26.4.1277
[54] Chen J, Tian R, Qiu M, et al. Trinorcucurbitane and
cucurbitane triterpenoids from the roots of Momordica
charantia. Phytochemistry 2008; 69: 1043-1048.
https://doi.org/ 10.1016/j.phytochem.2007. 10.020
[55] Saxena A, Vikram N. Role of selected Indian plants in
management of type 2 diabetes: A review . J Alternative
Comp Med 2004; 10: 369-378.
https://doi.org/ 10.1089/1075553043 23062365
[56] Singh LW. Traditional medicinal plants of Manipur as anti-
diabetics . J Med Plants Res 2011; 5: 677-687.
[57] Villegas R, Gao YT, Yang G, et al. Legume and soy food
intake and the incid ence of type 2 diabetes in the Shanghai
women's health study. Am J Clin Nutr 2008; 87: 162-167.
[58] Imai S, Fukui M, Kajiyama S. Effect of eating vegetables
before carbohydrates on glucose excursions in patients with
type 2 diabetes. J Clin Biochem Nutr 2014; 54: 7-11.
https://doi.org/ 10.3164/jcbn.13-67
[59] Imai S, Fukui M, Ozasa N, et al. Eating vegetables before
carbohydrates improves postprandial glucose excursions.
Diabet Med 2013; 30: 370-372.
https://doi.org/ 10.1111/dme. 12073
[60] Imai S, Fukui M, Kajiyama S. Food order as a significant
impact on postprandia l glucose and insulin levels. Diabetes
Care 2015; 38: e98-e99.
https://doi.org/ 10.2337/dc15-04 29
[61] Wong JM, Jenkins DJ. Carbohydrates digestibility and
metabo lic effects. J Nutr 2 007; 137: S2539-S2546.
[62] Ma J, Stevens JE, Cukier K, et al. Effects of a protein preload
on gastric emptying, glycemia, and gut hormones aft er a
carbohydrate meal in diet-controlled type 2 diabetes.
Diabetes Care 2009; 32: 1600-1602.
https://doi.org/ 10.2337/dc09-07 23
Received on 18-01-2017 Accepted on 16-02-2017 Published on 21-04-2017
DOI: https://doi.org/10.6000/1929-5634.2017.06.01.1
For Author's Personal Use
... Source: Own study based on the Inspection of Purchase and Processing of Agricultural Products [31] (pp. 8,20); [32] (p. 9); [33] (p. ...
Article
Full-text available
Vegetables constitute a major component of human food security. They are the main sources of essential nutrients including antioxidants, natural dyes, minerals, and vitamins. Eating habit issues related to the consumption of vegetables are gaining importance within the context of a healthy lifestyle, longevity, and physical fitness. Additionally, food quality is of primary importance, and so-called eco-food (defined as food as natural as possible, without fertilizers, pesticides, or preservatives) seems to be the most popular world-trend in healthy nutrition. Keeping these ideas in focus, research on vegetable consumption in Poland in the context of conventional or organic production was performed using online questionnaire surveys. The results revealed that the rate of vegetable consumption depended primarily on economic status, except for the potato, which was a staple cutting across all economic strata. Among the 108 analyzed respondents, 74% bought vegetables from certified organic farms. However, 59% bought organic vegetables “rarely” or “sometimes”, and only 15% “often”. Next, respondents chose to buy vegetables from fresh food markets (45%) and in local shops (41%). About 20% of the respondents acquired vegetables from their own farms. Among the reasons for choosing vegetables from certified organic farms, respondents mentioned in decreasing order: “desire for proper nutrition” (30%), “thinking that organic vegetables are healthier” (28%), and “organic vegetables are generally better” (7%).
... [11][12][13][14] The consumption of green vegetables with their active components such as carotenoid and flavonoid can play roles in glucose metabolism and prevention of risk of type-2 diabetes mellitus (DM). 15,16 Mangkokan leaf is an Indonesian term for Nothopanax scutellarius,and the Javanese people of Indonesia have a long history of consuming the leaves as part of their daily diets. The leaves are commonly consumed fresh, called "lalapan" or a salad, or cooked. ...
Article
Full-text available
The antioxidant activity of Nothopanax scutellarius (Burm. f.) Merr, an edible plant, can prevent oxidative stress in metabolic syndrome (MetS). Thus, our research aimed to study the effect of dietary inclusion of fresh or boiled N. scutellarius on body weight and biochemical markers of Wistar rats with MetS. Twenty-four male Wistar rats were divided randomly into four groups, i.e., normal control group, high-fat-high-fructose diet (HFFD) group, fresh N. scutellarius (FNs) group, and boiled N. scutellarius (BNs) group. The normal control group was fed only a standard diet during the entire experiment. High-fat and high-fructose (HFHFr) diet accompanied with 20% fructose in drinking water to induce MetS was given to the HFFD, FNs, and BNs groups for 29 days. This was followed by a 29-day intervention diet in which standard normal diet, fresh N. scutellarius-containing standard diet, and boiled N. scutellarius-containing standard diet were given to the HFFD, FNs, and BNs groups, respectively. HFHFr diet significantly (p<0.05) raised fasting blood glucose (FBG), serum triglyceride, total cholesterol, LDL-cholesterol, and malondialdehyde (MDA), and significantly (p<0.05) reduced HDL-cholesterol. After 29 days on the intervention diet, serum triglycerides, total cholesterol, and LDL-cholesterol levels were found to decrease, and HDL-cholesterol levels were found to increase significantly (p<0.05). Thus, it can be concluded that dietary intake of N. scutellarius for 29 days can improve MetS components, i.e., FBG, serum lipid profile, and MDA, similar to those seen in rats on a normal control diet.
... Other vegetables include those of the Alliaceae family such as shallots, leek, garlic and chives and the cruciferous vegetables that belong to the Brassicaceae family which include cabbage, cauliflower, kale and broccoli and those that belong to Cucurbitaceae family include squash, pumpkin, cucumber, melon and bitter gourd. They are all rich in carotenoids and tocopherols [4]. They are more nutritive compared to cereals because of the mineral content [5]. ...
Article
Full-text available
Raffia baskets are used in rural communities to preserve fresh vegetables for a given period of time. This method of storage is aimed at extending the shelf life of the vegetables until they are used. Thus, this study was aimed at determining the microbial succession during storage and susceptibility pattern of bacterial isolates from stored leafy vegetables to various antibiotics. Five (5) leafy vegetables namely, Bitter leaf (Vernomia anydalira), Water leaf (Talinum triangulare), Fluted pumpkin leaf, (Telfairia occidentalis), Okazi leaf (Gnetum africana) and Scent leaf (Ocimum gratissimum) were obtained from the Nigerian Stored Products Research Institute (NSPRI) farm, Port Harcourt. These vegetables were stored in a raffia basket for fourteen (14) days while another set of the vegetables were left in the open air as control. This set up was monitored for changes to occur. Standard microbiological techniques were employed for the various analyses of the vegetable samples. Both cultural and molecular characterizations of the isolates were done. The disc diffusion method was used in determining the susceptibility pattern of the bacterial isolates. The results of the predominant microorganisms identified were of the genus; Bacillus, Pseudomonas, Enterococcus, Enterobacter, Bordetella, Staphylococcus, Myroides, Escherichia, Serratia, Micrococcus and Acetobacter. Also, Bacillus species occurred in all the vegetables while Enterococcus faecalis, Acetobacter orientalis, Bordetella pertussis, Myroides xuanwuensis and Bacillus flexus were isolated on the third day of storage from the vegetables. The total heterotrophic bacterial counts ranged from 1.8 x106 cfu/g to 1.25 x107 cfu/g (bitter leaf), 9x105 cfu/g to 9.0 x106 cfu/g (Scent leaf), 7 x105 cfu/g to 1.88 x107 cfu/g (Okazi), 3.2x106 cfu/g to 1.05x107 cfu/g (Fluted pumpkin leaf) and 8.4 x106 cfu/g to 2.04 x107 cfu/g (water leaf). Antibiogram of bacterial isolates revealed that they were resistant to Augmentin and Ceftazidime according to Clinical Laboratory Standard Institute schemes. Combination of the antibiotics showed that most of the isolates were 100% susceptible to ciprofloxacin + erythromycin, and ciprofloxacin + ceftriaxone. The study revealed that for all the vegetables, those stored in the basket lasted longer and were fresher compared to those kept in the open space. This study revealed that the raffia baskets are suitable for storage and preservation of leafy vegetables, but microbial succession occurred as a result of increase in the period of storage leading to the proliferation of microorganisms. This could be from aerosols or by chance inoculation, through handling or materials used or other microorganisms which are inherent in the vegetables because of their contact with the soil or water used in the washing of the leaves.
... Agricultural products must always be present in human nutrition, as they are indispensable for equilibrated diets since they discharge dietary fiber, phytochemicals, vitamins, and minerals [1]. Although Romania has significant potential to increase organic farming, this is determined by subsidies from its common agricultural policy and free export of organic products to the countries of the European Union [2,3]. ...
Article
Full-text available
The aim of this study was to elicit answers referring to the consumer perception with respect to organic products. Factors that determine behavior were also considered: Gender, age, education, income, or social status. Analysis of data collected revealed that perception is the psycho-cognitive element that may determine the expression of behavior in relation to the organic production system. Furthermore, organic farming in Romania is a relatively recently formed market segment. The study was carried out by using a questionnaire developed specifically for this purpose, on a sample of 226 respondents. The data obtained from the survey were analyzed by employing the contingency coefficient and Pearson chi-square tests, using the SPSS software version 20. The perception of organic food is associated with its nutritional quality or sensory attributes (appearance, taste, flavor).
Article
This study renewed focus on Allmania nodiflora, a green leafy vegetable with diverse nutritional and medicinal properties. The bioaccessibility and the impact of in vitro simulated digestion on polyphenolics were investigated and identified using LC-MS. Although in vitro digestion reduced polyphenolics, the pancreatic digested sample showed a significant bioaccessibility of 97% with better metal ion binding activity (99%). Increased α-amylase and α-glucosidase inhibition (>45%) potentials were also observed in the digested samples. The presence of compounds such as rutin, caffeic acid, catechin, saikosaponin was also identified to be responsible for the enzyme inhibition against postprandial hyperglycemia. These results indicated that the pH of the digestive buffers is responsible for the structural changes in polyphenols for assimilation in the intestine. Hence, A. nodiflora leaf could serve as a functional food having higher assimilated polyphenolics with abundant therapeutic potential, which would be indispensible for future nutraceutical product development from green leafy vegetables.
Article
Full-text available
Background Khat chewing is a long standing social-cultural habit in several countries. Even though many people chew khat simply for its pleasurable and stimulatory effect, evidence showed widely-held belief among khat chewers in Ethiopia and other part of the world that khat helps to lower blood glucose while some studies are contradicted on the effect of khat. There is limited data about khat’s effect on blood glucose especially in our setting, Harar estern Ethiopia. Objective Primarily the present study aims to compare fasting blood sugar level among khat chewer diabetic and healthy individuals, and to asses risk factors associated with poor glycemic control in diabetic subjects. Method A cross-sectional study included 200 confirmed diabetic and healthy subjects. Fasting blood sugar was determined by enzymatic method glucose oxidase and glucose hexokinase. Glycemic control was also determined for diabetic subjects based on the last 2-month diabetic clinic visits and current measurement. Result (Median ± IQR [interquartile range]) fasting blood sugar difference among Khat chewer and non khat chewer were 159 ± 83 mg/dl and 202 ± 79 mg/dl respectively in diabetic subjects when tested by glucose oxidase. Similarly, in healthy non khat chewer and khat chewer, khat chewers has lower (Median ± IQR) fasting blood glucose level 82 ± 18 mg/dl than non khat chewers 94 ± 13 mg/dl when tested by glucose oxidase. Regarding risk factors associated with poor glycemic control in diabetic subjects, positive parental diabetes history, insulin medication, being overweight, obese were significantly associated with poor glycemic control. Conclusion There was significant effect of khat on median FBS among khat chewers in diabetic and healthy individuals. And the proportion of glycemic control was high among diabetic subjects. Recommendation Health care professional and patients should manage the risk factors to delay disease progression and restrain the damage. More studies should be conducted in randomized control trial manner to further elucidate khat effect on blood sugar level so that the actual effect of khat can be identified unlike in cross sectional where there may not be strong causal relationship.
Article
One of the processes involved in pathogenesis of diabetic complications is the polyol pathway, which is catalyzed by the enzymes – aldose reductase and sorbitol dehydrogenase. Inhibition of one, or both, of these enzymes will shut down the polyol pathway ameliorating diabetic complications. Consumption of leafy vegetables is a dietary regime for management of diabetes mellitus and its complications. Inhibitory effects of leafy vegetables on activities of the polyol pathway enzymes aldose reductase and sorbitol dehydrogenase, and mode(s) of inhibition of these enzymes by the most effective plant were evaluated. Aqueous extract of leaves of African eggplant (Solanum macrocarpon L), bitter leaf (Vernonia amygdalina Del.), fluted pumpkin (Telfairia occidentalis Hook.) and clove basil leaf (Ocimum gratissimum L), were incubated with substrates (glucose and sorbitol) and enzymes, and their percent inhibition of enzymes determined spectrophotometrically. Due to low IC50 value, the aqueous extract of bitter leaf was used to assess kinetics of both enzymes. With exception of African eggplant, all plants displayed stronger inhibition of sorbitol dehydrogenase than aldose reductase. Vernonia amygdalina exhibited the lowest IC50 for aldose reductase (78.03 µg∙mL⁻¹) and sorbitol dehydrogenase (22.17 µg∙mL⁻¹). Vernonia amygdalina inhibited aldose reductase and sorbitol dehydrogenase in a noncompetitive, and mixed non-competitive manner, respectively. The V. amygdalina extract displayed potent inhibition of polyol pathway enzymes, and it needs to be determined if consumption affects the responses.
Chapter
Spinach (Spinacia oleracea L.), an annual plant, is a green, leafy vegetable that can be grown in both spring and autumn. The nutritional value of fresh spinach, with 91% of moisture content, shows between 0.4% and 0.6% lipid content, around 2.9% protein content, and contains good levels of essential amino acids, except sulfurous amino acids (methionine) and tryptophan. Although the carbohydrate content is very low (2%–10%), the fiber content is high (2.2%). There are numerous health benefits associated with the consumption of spinach and these are attributed to its lipid-lowering properties and cardiovascular protection, antiobesity effects, hypoglycemic activity, antiinflammatory effects, anticancer properties, neuronal protection, antimacular degeneration, among others. Fresh spinach is attributed antioxidant properties because it contains a large amount of phenolic or flavonoid compounds, chlorophylls, ferulic acid and caffeic acid, quercetin, patuletin, spinacetin, and jaceidin, which are mainly found in the leaves, with maximum levels in the summer.
Article
Full-text available
Vegetables are essential for well-balanced diets since they supply phytonutriceuticals. About 3 billion people in the world are malnourished due to imbalanced diets. Regular consumption of a vegetable rich diet has undeniable effects on health since they have been strongly associated with improvement of gastrointestinal health, good vision, and reduced risk of heart disease, stroke, chronic diseases such as diabetes, and some forms of cancer. The mechanism by which vegetables decrease risk of disease is complex and largely unknown. Some phytochemicals of vegetables are strong antioxidants and are thought to reduce the risk of chronic disease by protecting against free radical damage, by modifying metabolic activation and detoxification of carcinogens, or even by influencing processes that alter the course of tumor cells. The dietary fiber content and type of different vegetables may also contribute to the overall health benefit. Each vegetable contains a unique combination of phytonutriceuticals. A great diversity of vegetables should be eaten to ensure that individual's diet includes a combination of phytonutriceuticals and to get all the health benefits.
Article
Full-text available
Carrot is a root vegetable with carotenoids, flavonoids, polyacetylenes, vitamins, and minerals, all of which possess numerous nutritional and health benefits. Besides lending truth to the old adage that carrots are good for eyes, carotenoids, polyphenols and vitamins present in carrot act as antioxidants, anticarcinogens, and immunoenhancers. Anti-diabetic, cholesterol and cardiovascular disease lowering, anti-hypertensive, hepatoprotective, renoprotective, and wound healing benefits of carrot have also been reported. The cardio- and hepatoprotective, anti-bacterial, anti-fungal, anti-inflammatory, and analgesic effects of carrot seed extracts are also noteworthy. All are discussed in this review article.
Article
Diets rich in vegetables and fruits are known to be protective against several diseases. Only a limited number of vegetables and fruits are consumed as part of the daily diet in Western countries. Historically, indigenous vegetables and fruits are known for their medicinal and nutritional value in countries where they were originated and/or domesticated. However, relatively few systemic studies and reviews were conducted to enumerate the potential of these vegetables to human health benefits. Although certain indigenous crops have received attention, the majority of these crops with strong potential biological activities were neglected and/or not reported. Considering the current health-related problems and obesity-related diseases, it is timely to enumerate the health-promoting properties of certain indigenous vegetables. In this report, we have reviewed some of the important crops indigenous to Southeast Asia and their potential health-promoting properties.
Article
We appreciated the article by Shukla et al. (1) showing that food order had a significant impact on postprandial glucose and insulin levels in obese patients with type 2 diabetes in U.S. However, we have already reported not only the same effect of eating vegetables before carbohydrates on postprandial glucose and insulin levels but also a significant improvement of HbA1c by as much as 1.5% in outpatients with type 2 diabetes who received instructions …
Article
Fruits and vegetables in the daily diet have been strongly associated with reduced risk for the major forms of cancer afflicting high-risk countries such as the United States. In populations across the world where intake of these foods is high, the prevalence of the most common cancers is lower. Basic research into the mechanisms that explain how fruits and vegetables provide cancer prevention goes well beyond the notion that these foods provide only a rich source of dietary fiber. Some components of fruits and vegetables are certainly strong antioxidants and function to modify the metabolic activation and detoxification/disposition of carcinogens, or even influence processes that alter the course of the tumor cell. Further research will continue to pinpoint the active and cancer-preventive elements of the diet. Current research should provide a dietary prescription for the next decade, and influence the development of designer produce enriched in the cancer prevention attributes provided by nature.
Article
Unconventional legumes are promising in terms of nutrition, providing food security, agricultural development and in crop rotation in developing countries. The wild legumes are in great demand as food; livestock feed and pharmaceutically valued products. The anti-nutritive factors (ANFs) may be defined as those substances generated in natural feed stuffs by the normal metabolism of species and by different mechanisms e.g inactivation of some nutrients, interference with the digestive process or metabolic utilization of feed which exert effects contrary to optimum nutrition. Being an ANF is not an intrinsic characteristic of a compound but depends upon the digestive process of the ingesting animal. Some of the phytochemiclas such as phytic acid, isoflavenoids, total phenolics, alkaloids, cyanogens and tannins play an important role as showing therapeutic effect in living body.
Article
PPARγ activating drugs show various salutary effects in preclinical models of neurodegenerative disease. The decade-long clinical usage of these drugs as antidiabetics now allow for evaluation of patient-oriented data sources. Using observational data from 2004-2010, we analyzed the association of pioglitazone and incidence of dementia in a prospective cohort study of 145,928 subjects aged 60 years or above who, at baseline, were free of dementia and insulin-dependent diabetes mellitus. We distinguished between non-diabetics, diabetics without pioglitazone, diabetics with prescriptions of less than eight calendar quarters of pioglitazone and diabetics with eight and more quarters. Cox proportional hazard models explored the relative risk of dementia incidence dependent on pioglitazone use adjusted for sex, age, use of rosiglitazone or metformin and cardiovascular comorbidities. Long-term use of pioglitazone was associated with a lower dementia incidence. Relative to non-diabetics, the cumulative long-term use of pioglitazone reduced the dementia risk by 47% (RR=0.53, p=0.029). If diabetes patients used pioglitazone less than eight quarters, the dementia risk was comparable to those of non-diabetics (RR=1.16, p=0.317), and diabetes patients without a pioglitazone treatment had a 23% increase in dementia risk (RR=1.23, p<0.001). We did not find evidence for age effects, nor for selection into pioglitazone treatment due to obesity. These findings indicate that pioglitazone treatment is associated which a reduced dementia risk in initially non-insulin dependent diabetes mellitus patients. Prospective clinical trials are needed to evaluate a possible neuroprotective effect in these patients in an ageing population. This article is protected by copyright. All rights reserved. © 2015 American Neurological Association.