Impact of Adding a Millet Diet on Glycemic Control and Lipid Profile in Patients with Type 2 Diabetes Mellitus

Abstract

Context:

Millets contain complex carbs, which are “good” kinds of carbs. These carbs do not propel blood sugar to rise to a dangerous extent. These findings should provide insight into the possibility of ameliorating type 2 diabetes through diet modulation.

Aims:

This study aims to study the effect of millet intake on glycemic control and lipid profile on patients of type 2 diabetes mellitus.

Settings and Design:

This study was a cross-sectional study.

Materials and Methods:

After following the inclusion and exclusion criteria, study participants were enrolled. Baseline glycated hemoglobin (HbA1c) and lipid profile were recorded at day zero. A booklet on millet uses and its benefits on glycemic control were provided to the patients in their vernacular language. A daily diary was provided to each patient to note down their daily intake of millets. At the end of 6 weeks, HbA1c and lipid profile of each patient was recorded.

Statistical Analysis Used:

The results of the study were analyzed by nonparametric Wilcoxon’s test of significance and nonparametric Kruskal–Wallis test was used.

Results:

There was a significant change in both glycemic control and lipid profile of the study participants. The fasting blood sugar (FBS) for the study participants reduced by more than 20% from 237 ± 50 to 188 ± 33, which is statistically significant with a P < 0.05. Further, there was a 2.7% statistically significant reduction in the HbA1c levels of the study participants.

Conclusions:

The intake of millet even in a single meal per day significantly improved the glycemic control, especially the FBS and lipid profile.

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder and a major public health concern worldwide. T2DM is characterized by high levels of blood glucose. India is one of the countries with the highest prevalence of diabetes.[1] The main reason for the occurrence of T2DM is insulin resistance and progressive loss of adequate beta-cell insulin secretion.[2] This combined lack of insulin and increased resistance to insulin further results in hyperglycemia.

Overeating, physical inactivity, and a high-fat diet, particularly associated with insulin resistance, are not only risk factors for the development of hyperglycemia but also for dyslipidemia.[3]

Current evidence shows that overnutrition at the cellular level causes the production of oxidative stress via the activation of reactive oxygen species.[4] This process further tends to increase inflammation and contributes to the development of both macro and microvascular complications associated with diabetes, including retinopathy, neuropathy, nephropathy, atherosclerosis, stroke, myocardial infarction, and cerebrovascular accidents.[5] These long-term complications become the leading cause of morbidity and mortality and financial strain on the healthcare system.[6]

Changing lifestyle and food habits, ceasing smoking, and engaging in physical activity can avoid and delay the onset of these complications. And for people who have elevated blood glucose and lipid levels even after this, one should start on pharmacotherapy.[7] However, these pharmacological agents have shown evidence of various side effects and intolerance, even after confirming a safe and efficient profile.

Therefore, there is a great demand for alternative treatments that provide strong clinical benefits with no side effects. Thus, a millet-based diet is considered the best alternative of interest to be assessed for its antidiabetic and lipid-lowering properties.

Recently, millet has been found to be nutritionally superior and cost-effective with no or fewer side effects compared to other traditional food grains due to the higher proportions of fiber, polyphenols, and antioxidants.[8]

Millet is an important food crop in Asian and African countries. FAO reports have shown that millet ranks 15^th among all crops in terms of calories produced for human consumption and that worldwide, millet production may be the primary calorie source for more than 500 million people.[9]

A recent systematic review and meta-analysis of low glucose index (GI) millets (including sorghum) and their effects on managing and reducing the risk of developing type 2 diabetes shows that millets have a beneficial effect on various outcomes, such as fasting and postprandial blood glucose levels, insulin index, and glycated hemoglobin (HbA1c) marker levels. This ability to manage and prevent diabetes may also help toward the management of hyperlipidemia.[10] However, further studies are needed to understand the effects of millet consumption on blood lipid management.

In the present study, we aimed to extend our research on the health benefits of millet by clarifying the beneficial effects of millet on the glycemic index, lipid, and insulin levels over 60 days in patients with T2DM. A GI score of more than 70 is dangerously high. Such foods raise blood sugar levels aggressively and end up harming the health of diabetes patients.[6] Millets are foods with low GI and. Complex carbs, which are “good” kinds of carbs. These carbs do not propel blood sugar to rise to a dangerous extent.[7]

Health benefits of consuming millets

1. Best Gluten-free alternative: People with celiac disease or gluten intolerance often find it hard to find promising rice, wheat, and barley alternatives. Due to their gluten-free requirement, millets perfectly resonate with the diet requirements of such people

2. Lowers cholesterol: It is the potential of soluble fibers present in millet that diminish levels of cholesterol in the body. The proteins in millets also work toward reducing the triglyceride count.

The results of this study provided insight into the possibility of ameliorating type 2 diabetes through diet modulation using millets.

Aims and objectives

1. To study the effect of millet intake on glycemic control on patients of diabetes

2. To study the effect of millet intake on the lipid profile of the patients

3. To give knowledge and awareness to diabetic patients about the millet diet.

MATERIALS AND METHODS

Study design

This study was a cross-sectional, noninterventional, and time-bound study carried out in the Outpatient Department (OPD) of Medicine Department at Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India. After following the inclusion and exclusion criteria, study participants were enrolled. Baseline HbA1c and lipid profile were recorded at day zero. A booklet on millet uses and its benefits on glycemic control were provided to the patients in their vernacular language. The booklet entitled Nutritional and Health Benefits of Nutricereals by Rao et al. published by ICAR - Institute of Millet Research, Hyderabad, was used.[11] A daily diary was provided to each patient to note down their daily intake of millet in their diet in any form such as bread, porridge, or khichdi. The study participants were given the liberty to add any kind of millet such as pearl millet or bajra (most commonly used in this region), Sorghum millet or jowar (second most common), finger millet or ragi, foxtail millet or kangni both in minor quantities, the type of millet used was not recorded. At the end of 6 weeks, HbA1c and lipid profile of each patient was recorded.

Study duration

The duration of the study was 2 months.

Study subjects

One hundred participants.

Inclusion criteria

1. Patients diagnosed with diabetes and on regular treatment

2. Age above 18 years

3. No known mental problems such as depression, anxiety, etc., or treatment with psychotropic drugs.

Exclusion criteria

1. No history of other chronic disease such as chronic kidney disease, liver disease, or other comorbidity

2. Patients who are allergic to millets

3. Patients are already on any millet diet including any form such as jowar, bajra, or ragi.

The case study pro forma containing demographics, disease description, lifestyle, and treatment were filled for from subjects. Before the recruitment of the subjects, informed consent was obtained from all the participants. Ethical approval was obtained from the institutional ethics committee of Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India. All the data collected from the patients were kept confidential and were used only for statistical analysis of the study.

Data collection

HbA1c and lipid profile of the subjects were recorded at the time of recruitment, i.e., day 0 and 6 weeks. The daily diary maintained by the subjects was analyzed for consumption of millets every 2 weeks till 6 weeks, i.e., at 2 weeks, 4 weeks, and 6 weeks. Furthermore, elf monitoring of fasting blood sugar (FBS) was recorded.

OBSERVATIONS AND RESULTS

This cross-sectional noninterventional study was conducted in the OPD of Medicine Department at Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India. Recruitment of 100 participants was concluded during the first 15 days of the study and then the follow-up of 6 weeks was done as per protocol. The mean age of the study participants was 55.56 ± 9.67 years. There were a total of 44 females and 56 males that participated in the study. The mean baseline FBS of the participants was 237.27 ± 49.54 mg/dL. The mean baseline HbA1c level was 10.8 ± 1.5 mmol/L. Details of baseline stats are given in Table 1.

Table 1.

Baseline variables of various parameters of this study

	Mean±SD
Age	55.56±9.697
HbA1c	10.823±1.5099
FBS	237.27±49.547
TC	271.55±31.501
Triglycerides	251.63±61.974
HDL	48.73±8.673
LDL	143.76±13.519
VLDL	33.83±4.926

SD=Standard deviation, HbA1c=Glycated hemoglobin, FBS=Fasting blood sugar, HDL=High-density lipoprotein, LDL=Low-density lipoprotein, VLDL=Very LDL, TC=Total cholesterol

Eighty-five percent of the patients were on metformin and glimepiride. Very few of the patients were on Insulin as described in Table 2. Majority of the patients were on metformin.

Table 2.

Frequency of patients on various drugs/combinations

Drugs	Frequency (%)
glimepiride, dapagliflozin	1 (1.0)
Insulin mixtard 30/70	1 (1.0)
Metformin, glimepiride	85 (85.0)
Metformin, insulin mixtard 30/70	1 (1.0)
Metformin, insulin mustard 30/70	1 (1.0)
Metformin, dapagliflozin	1 (1.0)
Metformin, glimepiride, dapagliflozin	1 (1.0)
Metformin, glimepiride, insulin glargine	2 (2.0)
Metformin, tenepride	4 (4.0)
Metformin, voglibose	1 (1.0)
Metformin, voglibose, glimepiride	1 (1.0)
Tenepride, metformin, glimepiride	1 (1.0)

To fulfill our third objective a booklet on millet uses and its benefits on glycemic control was provided to the patients in their vernacular language. Each patient was given a detailed explanation about the benefits of the use of millets and all the questions and queries were resolved. The recruited participants were then advised to take millet in their diets. A daily diary was provided to each patient to note down their daily intake of millets. The millet intake of the patients is given in Table 3. Overall intake of millets in one or more meals was recorded by 97% of the patients. Out of which 56% of the study participants took millet in two meals and 31% took millet in three meals. The form in which they took the millet was not recorded as it was not the objective of the study. The portion size of the millets was not considered. The results of the study were then tabulated in the form of mean and standard deviation and analyzed by nonparametric Wilcoxon’s test of significance and for intergroup comparison nonparametric Kruskal–Wallis test was used. The level of significance was determined and P < 0.05 was taken as statistically significant.

Table 3.

Frequency of intake of millets per day

Intake of millets (number of meals per day)	Frequency (%)
0	3 (3.0)
1	10 (10.0)
2	56 (56.0)
3	31 (31.0)

• Various levels of significance possible are

• P > 0.05 – Nonsignificant (ns)

• P < 0.05 – Significant (s).

After follow-up of 6 weeks, the data were recorded [Table 4]. There was a significant change in both glycemic control and lipid profile of the study participants. The FBS for the study participants reduced by more than 20% from 237 ± 50 to 188 ± 33, which is statistically significant with a P < 0.05. Further, there was a 2.7% statistically significant reduction in the HbA1c levels of the study participants.

Table 4.

Comparison of various parameters for glycemic control and lipid profile (n=100)

Parameters	Baseline, mean±SD	6 weeks, mean±SD	P
HbA1c	10.8±1.5	10.5±1.6	<0.05
FBS	237±50	188±33	<0.05
TC	271.55±31.5	232±34.1	<0.05
Triglycerides	251.633±61.9	210.38±49.7	<0.05
HDL	48.73±8.7	43.98±6.5	<0.05
LDL	143.76±13.5	137.18±12.3	<0.05
VLDL	33.83±4.9	33.75±5.1	0.846

SD=Standard deviation, HbA1c=Glycated hemoglobin, FBS=Fasting blood sugar, HDL=High-density lipoprotein, LDL=Low-density lipoprotein, VLDL=Very LDL, TC=Total cholesterol

Further, there was a statistically significant reduction in serum triglyceride and total cholesterol (TC) levels. However, serum high-density lipoprotein (HDL) levels reduced from 48.73 ± 8.7 to 43.98 ± 6.5, which was also statistically significant.

On the analysis of data based on the intake of millets in number of meals per day taken by the study participants, it can be inferred that there is no significant change in glycemic control and lipid profile of the participants who have not taken any millets in their meals [Table 5].

Table 5.

Evaluation of glycemic control and lipid profile based on intake of millets no meals a day (n=3)

Parameters	Baseline	6 weeks	P
HbA1c	12.27±2.46	12.57±2.40	>0.05
FBS	213.00±34.00	162.33±11.55	>0.05
TC	289.00±55.51	247.67±45.08	>0.05
Triglycerides	260.00±57.66	221.67±60.86	>0.05
HDL	53.00±12.17	46.67±9.07	>0.05
LDL	143.00±3.46	134.33±9.87	>0.05
VLDL	31.33±2.52	37.67±8.08	0.285

HbA1c=Glycated hemoglobin, FBS=Fasting blood sugar, HDL=High-density lipoprotein, LDL=Low-density lipoprotein, VLDL=Very LDL, TC=Total cholesterol

However, those who have taken millet even in one meal a day had a statistically significant reduction in FBS from 266.10 ± 42.47 to 205.80 ± 32.09, TC from 281.70 ± 43.33 to 242.30 ± 46.24 and triglycerides from 290.40 ± 93.20 to 225.00 ± 69.27 [Table 6]. There was no significant reduction in levels of HbA1c in this group of patients. On further evaluation of the data of levels of HDL and very low-density lipoprotein (VLDL), there was no significant statistical difference found.

Table 6.

Evaluation of glycemic control and lipid profile based on intake of millets in one meal a day (n=10)

Parameters	Baseline	6 weeks	P
HbA1c	11.38±1.29	11.29±1.26	0.287
FBS	266.10±42.47	205.80±32.09	<0.05
TC	281.70±43.33	242.30±46.24	<0.05
Triglycerides	290.40±93.20	225.00±69.27	<0.05
HDL	49.10±7.39	44.90±5.36	>0.05
LDL	142.00±11.80	134.60±11.73	<0.05
VLDL	34.80±5.88	33.90±5.34	0.441

HbA1c=Glycated hemoglobin, FBS=Fasting blood sugar, HDL=High-density lipoprotein, LDL=Low-density lipoprotein, VLDL=Very LDL, TC=Total cholesterol

However, those who have taken millet in two or three meals a day had a statistically significant reduction in HbA1c by about 3% and 4.6%, respectively, FBS by 20.2% and 20.7%.

There was a statistically significant reduction in levels of TC HDL and low-density lipoprotein (LDL) also [Tables 7 and 8]. On further evaluation of levels of VLDL, there was no significant statistical difference found in the two groups.

Table 7.

Evaluation of glycemic control and lipid profile based on intake of millets two meals a day (n=56)

Parameters	Baseline	6 weeks	P
HbA1c	10.83±1.50	10.51±1.47	<0.05
FBS	238.25±49.11	190.11±31.74	<0.05
TC	273.11±28.06	234.77±30.71	<0.05
Triglycerides	249.54±59.24	211.95±50.12	<0.05
HDL	48.16±7.57	43.54±5.52	<0.05
LDL	144.50±14.36	138.41±13.11	<0.05
VLDL	33.41±4.84	33.23±5.45	0.848

HbA1c=Glycated hemoglobin, FBS=Fasting blood sugar, HDL=High-density lipoprotein, LDL=Low-density lipoprotein, VLDL=Very LDL, TC=Total cholesterol

Table 8.

Evaluation of glycemic control and lipid profile based on intake of millets three meals a day (n=31)

Parameters	Baseline	6 weeks	P
HbA1c	10.50±1.45	10.01±1.56	<0.05
FBS	228.55±51.44	181.16±34.75	<0.05
TC	263.77±30.50	223.84±34.39	<0.05
Triglycerides	242.10±52.93	201.74±41.27	<0.05
HDL	49.23±10.69	44.23±8.13	<0.05
LDL	143.06±13.41	136.06±11.20	<0.05
VLDL	34.52±4.95	34.26±4.15	0.701

HbA1c=Glycated hemoglobin, FBS=Fasting blood sugar, HDL=High-density lipoprotein, LDL=Low-density lipoprotein, VLDL=Very LDL, TC=Total cholesterol

DISCUSSION

The basis of compliance to intake of millet is the level of awareness and orientation toward their benefits and advantages in the management of DM. The main short-term goal in the management of diabetes is control over FBS levels. Depending on the glycemic control, the long-term goal of prevention/delay of onset of complications can be achieved. Thus, to achieve this level of awareness, each participant was given ample opportunity to discuss the advantages of use of millet in their diet.

The results of this study showed the effectiveness of millets in diet helps to achieve one of the main goals of the management of DM. There was more than 20% reduction in FBS levels in the study participants. A similar effect can be seen on HbA1c, with a reduction of nearly 2.7%. In a study conducted by the National Institute of Nutrition (ICMR), the GI of sorghum-based food was assessed under the National Agriculture Innovation Project. The results of that study also revealed that this food positively affects postprandial blood glucose levels and glycosylated hemoglobin.[12]

The effect of intake of millets on lipid profile is also clinically significant. The effect on glycemic control and lipid profile can be attributed to the properties of the millet. The phytochemicals present in the seed coat of millets, which have antioxidant properties, prevent the oxidation of LDLs and raise the levels of HDL cholesterol in the end.[11] Many systematic reviews and meta-analyses have been conducted to provide evidence of the impact of millet consumption on the lipid profile. Anitha et al. reviewed 19 studies, which showed that the consumption of millets reduced levels of TC, triacylglycerol, LDL cholesterol, and VLDL cholesterol (P < 0.01) by 8.0%, 9.5%, 10%, and 9.0%, respectively.[10]

On further analysis of the data depending on the intake of millets, it can be definitely inferred that actual consumption of millets may be one of the factors in determining the improvements in both glycemic control and lipid profile. This can be easily seen in participants who have not taken millets in their diets. In such participants, though there was improvement in FBS but there was a slight increase in HbA1c levels. This can be because of the effect of drugs that can control the FBS levels but were unable to lower the HbA1c levels. As there was no intake of millet, the positive effects of these dietary modifications were not recorded. Further also there was no significant improvement in the lipid profile of these patients.

The above fact can be further strengthened by the significant improvement in FBS in participants who have consumed millet in a single meal only. However, there was no significant improvement in levels of HbA1c in this group of participants. This group of participants also showed significant improvement in lipid profile.

Further strengthening of the fact that intake of millets has effect on both glycemic control and lipid profile can be easily inferred from the data of participants who consumed millets in two or more meals per day. There was significant improvement in FBS and HbA1c in participants on two or three meals per day. The lipid profile also showed statistically significant improvement in both the groups.

One of the foremost reasons for these effects is the low glycemic index of the millet, based on which the patient might feel less hunger, and will lead to less consumption of carbohydrates. Further, there is a high amount of fiber in millet which also contributed to slow and consistent release of sugar into the bloodstream thereby decreasing the spike in blood sugar levels. This can further be explained by the presence of inhibitors of alpha-glycosidase and pancreatic amylase in millets. These inhibitors reduce the hydrolysis of complex carbohydrates.[13]

The dietary fibers can be divided into two types, soluble and insoluble. Soluble fibers have the ability to form a gel-like substance that aids in reducing blood cholesterol levels, particularly LDL. These fibers promote the production of saliva in the mouth and help lubricate food. As food moves into the stomach, fibers create a sense of fullness, push high-fat foods out of the diet, and slow down gastric emptying to facilitate optimal digestion and absorption of nutrients. Within the small intestine, fibers dilute the contents and delay the absorption of dietary fat, cholesterol, and glucose. In addition, bile salts (glycocholate and taurocholate) and minerals may be absorbed and trapped by the fibers. This trapping or absorption by fibers directly impacts cholesterol absorption and metabolism.[13]

Limitations of the study

There are a few weaknesses of the study. First, the methodology used in the study is mostly used in studies that include all the varieties of millet irrespective of the type. Further studies can be planned to include different varieties of millet as individual ingredients of meals. The second limitation of this study was that there was no control population taken to compare the effect of intake of millets. The third limitation is that the data was collected in two contact with the patient and there was only one follow-up of the therapy which might involve bias. Fourth, the data collection of intake of millet was based on the diary entry of the patients which might lead to recall bias. The fifth limitation of this study is that the follow-up period was too short, i.e., only 6 weeks which cannot devise the proper potential of the changes in the levels of HbA1c and lipid profile.

CONCLUSIONS

Millets are “future crops” that have the potential to merge as a powerful and effective solution to the management of DM due to the high levels of micronutrients and macronutrients present in them. Physicians, nutritionists, and patients themselves should try to incorporate millet into their diet and follow a strict, balanced, and planned diet in combination with regular exercise or walking. No single food provides 100% nutrients, so it is a prerequisite to incorporate them wisely into our diet in combination with other food sources. A meal comprising a combination of pulses, millet, and functional foods is the ideal meal.

The intake of millet even in a single meal per day significantly improved the glycemic control, especially the FBS and lipid profile. The glucose-lowering effect of millets might be a result of the interaction of various chemical and physical properties for the constituents of the millets. Thus, it is suggested that there must be the incorporation of the millets in diet of patients of DM and awareness must be spread about the use of millets in the diet.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.