Bran more effective than whole grain in alleviating obesity symptoms: Study
The researchers looked at the effect of both finger millet whole grain and finger millet bran supplementation over a period of 12 weeks and found that the inclusion of 10% finger millet bran in a high-fat diet held more beneficial effects than a high-fat diet with finger millet whole grain.
The results suggested that the bran prevented body weight gain, improved lipid profile and anti-inflammatory status, alleviated oxidative stress, regulated the expression levels of several obesity-related genes as well as increased the amount of beneficial gut bacteria Lactobacillus, Bifidobacteria and Roseburia and suppressed that of Enterobacter.
They concluded that bran should be considered as a “nutraceutical ingredient for the development of functionally enriched food products for the management of obesity and associated metabolic complications”.
The mice were divided between four groups: the control group fed a normal diet with 10% fat as energy; a high-fat diet with 45% energy from fat; the same high-fat diet with 10% bran; the high-fat diet with 10% whole grain.
Explaining the difference
The researchers said the lack of weight reduction seen in the high-fat whole grain group could be due to its high starch content.
“This finding emphasises that the consumption of whole grain low in glycaemic index or diets enriched with bran is more beneficial for preventing weight gain.”
The high fat and bran diet counteracted the increase in serum total cholesterol, cholesterol ester, and LDL (low density lipoprotein) and VLDL (very low density lipoprotein) cholesterol concentrations caused by the high fat diet, the researchers said. Meanwhile, although there was no difference in weight gain between the high fat group and the high fat and whole grain group, the latter did still show a decrease in total cholesterol and cholesterol ester concentrations.
Both the bran and whole grain groups saw some oxidative stress parameters tempered, which the researchers put down to the grains’ phenolic antioxidants and dietary fibres.
The bran diet decreased the expression of all genes involved in inflammation, while the whole grain diet did so for only some of them.
A gut feeling
Previous studies have suggested that obese individuals have decreased levels of Lactobacillus, Bifidobacteria, Roseburia, Akkermansia and Bacteroidetes. Likewise increased levels of Enterobacteriaceae members have been reported – with Enterobacter cloaca thought to contribute to the development of obesity through changes to gut barrier functioning leading to inflammation and metabolic endotoxaemia.
As expected then, the results of this study showed the high fat diet reduced these ‘friendly’ gut bacteria and increased Enterobacter. However, both bran and whole grain feeding reversed these microbial imbalances and showed a “prebiotic effect” when compared to the normal diet and high-fat diet alone. The researchers linked this phenomena with the decreased expression of an obesity gene (FAS).
Again, both grains lowered the Enterobacter content found in the cecum pouch at the beginning of the large intestine, however no reduction in the expression of the pro-inflammatory cytokine Interleukin 6 was seen for the whole grain diet.
The researchers from various institutions in India said finger millet, also known as ragi, was an important food crop in Africa and India.
They added that given anti-obesity medication had been shown to cause side effects, dietary alternatives should be explored as an option to tackle obesity-related health problems.
“Exploration of alternative approaches is desirable, and that worth exploring is consumption of whole grains, plant-derived dietary molecules including polyphenols, NSP (dietary fibres), prebiotics and probiotics.”
Source: British Journal of Nutrition
Vol. 112, Iss. 9, pp. 1447-1458, doi:10.1017/S0007114514002396
“Finger millet bran supplementation alleviates obesity-induced oxidative stress, inflammation and gut microbial derangements in high-fat diet-fed mice”
Authors: N. Murtaza, R. K. Baboota, S. Jagtap, D. P. Singh, P. Khare, S. M. Sarma, K. Podili, S. Alagesan, T. S. Chandra, K. K. Bhutani, R. K. Boparai, M. Bishnoi and K. K. Kondepudi