Type of analysis: Scientific studies undertaken on millets in relation to hyperlipidaemia were widely searched and collated. A systematic review and meta-analysis was conducted to identify any evidence of positive or negative effects from the impact of consuming millets. This included impacts on: total cholesterol (TC), triacylglycerol (TG) , high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and very-low-density lipoprotein cholesterol (VLDL- C).
A total of 19 efficacy studies on humans were found and analysed.
Millets studied: In total 5 types of millets were included in the studies: finger millet, foxtail millet, barnyard millet, sorghum and/or a mixture of millets (finger millet and little millet)
How millets were consumed: Millets were included in meals and in a variety of forms. Some included millet biscuits, burfi (sweet), porridge, buns, boiled in water (similar to rice), roti (flatbread), dumpling, upma or a drink. The amount of millets provided to the intervention groups varied from 50 g to 200 g (dry weight basis) either in one or divided into two meals per day.
Study shows consumption of millets reduce total cholesterol, triacylglycerol and BMI.
- Reduced total cholesterol by 8%, lowering cholesterol in the people studied, from high to normal levels.
- Resulted in nearly a 10% decrease in low and very low-density lipoprotein cholesterol (commonly viewed as ‘bad cholesterol’) and triacylglycerol levels in blood. Through these reductions, the levels went from above normal to normal range.
- Led to a slight increase in what is ‘commonly’ called the good cholesterols (high-density lipoprotein cholesterol).
- Lowered blood pressure with the diastolic blood pressure decreasing by 5%.
- Reduced BMI by 7% in people who were overweight and obese, showing the possibility of returning to a normal BMI.
- Additional data collected from other sources showed that millets are much higher in unsaturated fatty acids with 2 to 10 times higher levels than refined wheat and milled rice, as well as being much higher than whole grain wheat.
Reducing total cholesterol by 8%
Three of the studies demonstrated that millet consumption could bring above high levels of cholesterol to normal levels (from 215.8 ±12.5 to 167.5 ±3.2mg/dl (normal being <200).
Slight increase in high-density lipoprotein cholesterol (HDL-C) commonly viewed as ‘good cholesterol’ because it helps remove other forms of cholesterol from your bloodstream.
There was 6% increase in HDL-C level after consuming millet-based meals compared to regular rice or wheat meal (43.4 ± 7.5 to 46.0 ± 7.6 mg/dl).
Five studies demonstrated the increase of HDL from low to normal (38.7 ± 1.3 to 41.5 ± 0.8 mg/dl).
Reducing low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C), commonly viewed as ‘bad cholesterol’, by 9.7% and 9% respectively.
Five studies demonstrated the reduction of LDL-C from above normal level of 116.5 ± 10.0 to normal level of 92.6 ± 8.7 mg/dl. One long-term cross-sectional study showed the reduction from high level of LDL-C (160.1± 26 mg/dl) to moderately high level (140.1 ± 16.5 mg/dl).
Reduced Body Mass Index (BMI) for people overweight and obese to almost normal levels
Consuming millets reduced BMI by 7% in people who were overweight and obese, (from a BMI of 28.5 ± 2.4 to 26.7 ± 1.8 kg/sqm) showing the possibility of returning to a normal BMI (<25).
Reducing triacylglycerol levels in blood by 9.5%
Two of the studies showed the plasma triacylglycerol levels reduced from a hypertriglyceridaemic (>150 mg/dl) condition to normal (<150 mg/dl) if a millet-based meal is consumed once a day for three months instead of the regular rice- and/or wheat-based diet.
Cross-sectional studies conducted by recording more than two years of millet consumption information showed a similar reduction.
Four of the studies demonstrated that millet consumption could bring above normal levels of triacylglycerol to normal levels: from 170.4 ±17.2 to 128.6 ±14.9 mg/dl (normal being <150).
Decreased blood pressure
Consuming millets decreased blood pressure with the diastolic blood pressure decreasing by 5%. This was based on five studies.
The positive benefits of millets in this systematic review support millets being in the diet. Given their benefits compared to major staples, it also supports the need to diversify major staples with millets. This is further supported by the fact that millets have nutritional and health benefits such as low glycaemic index and high levels of several necessary micro- and macronutrients (e.g. iron, zinc, calcium and protein).
Additionally, millets are a ‘smart food’: not only ‘good for you’ but also ‘good for the planet’ and ‘good for the farmer’, i.e. environmentally sustainable, climate-smart, with a lower carbon footprint. Therefore, they should also be part of solutions for reforming the food system.
This will help contribute to a range of UN Sustainable Development Goals such as Zero Hunger, Good Health and Well-being, Responsible Consumption and Production, and Climate Action.
Design millet-based meals especially where atherosclerotic cardiovascular diseases and weight management are potential high risks.
- Study all the types of millets and different varieties: Only five millets were assessed and no studies distinguished by variety.
- Identify variations by types of processing: None of the studies compared results on the blood lipid profile by different types of processing.
- Conduct longer term studies: The study duration varied from 21 days to three months. However, having evidence for a much longer duration of a year or more will be useful evidence.
- More detailed research is needed that is focused on weight management and including different ages, gender and cultures.
- More studies that include all the relevant parameters for cardiovascular disease: Only two out of 6 studies determined total cholesterol to HDL cholesterol ratio, which is an important risk marker for cardiovascular disease. Therefore, it is also important to include all relevant parameters while conducting the dietary interventions including the impact on hyperlipidaemia and other risk markers for cardiovascular disease.
- Studies on non-alcoholic fatty liver disease (NAFLD): Because millets were identified to reduce hyperlipidaemia, it is expected that millets may have a positive effect also on reducing or preventing NAFLD. This has never been studied in regard to millets and NAFLD is predicted to become a major cause of liver-related morbidity and mortality by 2030. (Dorosti et al., 2020)
- Undertake studies in more geographic locations: Out of 17 studies, one study was conducted in Sri Lanka, two in China and the remaining 14 in India, indicating a geographical limitation.
Dr S Anitha
Senior Nutrition Scientist, ICRISAT
Dr Rosemary Botha
Monitoring, Evaluation and Learning Lead,One Acre Fund
Former Research Analyst, International Food Policy Research Institute (IFPRI )
Ms Joanna Kane-Potaka
Assistant Director General, ICRISAT
Executive Director, Smart Food
Professor Ian Givens
Director at University of Reading’s Institute of Food, Nutrition and Health (IFNH)
Dr Takuji W Tsusaka,
Kobe University, Japan
Dr Ananthan Rajendran,
Scientist, National Institute of Nutrition (NIN)
Dr Raj Bhandari
Rep. on the Indian National Technical Board of Nutrition
Rohit Pillandi, Senior Communication Officer, ICRISAT
Dr S Anitha, Senior Scientist, Nutrition, ICRISAT, India
Nutrition study series
This study is part of a series that has been worked on for the last four years under the Smart Food initiative and will be progressively released in 2021, including systematic reviews on the impacts of millets on
- Iron deficiency anemia
- Managing lipid profile (cholesterol, obesity, hypertension and cardiovascular disease)
- Calcium deficiencies and requirements
As part of this, ICRISAT and the Institute for Food Nutrition and Health at the University of Reading have formed a strategic partnership to research and promote the Smart Food vision that our diets become healthier, more sustainable on the environment and good for those who produce it.
Author affiliations (at time of the work):
1.Smart Food Initiative, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India
2.Development Strategy and Governance Division, International Food Policy Research Institute (IFPRI), Lilongwe, Malawi
3.Institute of Food, Nutrition and Health, University of Reading, Reading, United Kingdom
4.Food Chemistry Division, National Institute of Nutrition (NIN), Hyderabad, India
5.Organization for Advanced and Integrated Research, Kobe University, Kobe, Japan
6.National Technical Board of Nutrition, Government of India, New Delhi, India