[ad_1]
BARCELONA – A low fat vegan diet induces changes in gut microbiota related to a change in body composition and insulin sensitivity, as well as a weight loss, according to the results of the study. a randomized controlled trial conducted in overweight / obese adults.
Over the 16 weeks of intervention, body weight was significantly reduced in those following a vegan diet compared to those who maintained their daily (non-vegan) diet, with a loss of -5.8 kg (P <0.001), largely due to a decrease in body fat, with a therapeutic effect of -3.9 kg (P <0.001). Visceral fat was also significantly reduced with the vegan diet.
No caloric restriction was imposed in both diets.
Hana Kahleova, MD, PhD, director of clinical research at the Physicians Committee for Responsible Medicine (PCRM), Washington, DC, led the work and will present the results here at the 2019 Annual Meeting of the European Association for the study of diabetes (EASD).
"It's a very good result of about a pound or a half kilogram [weight loss] on average per week in the vegan group, "said Kahleova.
Kahleova explained that previous work had shown that individuals could lose twice as much weight with a vegan diet as a non-vegan diet with the same calorie intake. "In conducting our study, we wanted to know why this was so," she noted in an interview with Medscape Medical News.
The results suggest changes in the intestinal microbiome producing beneficial effects, she said.
"Eating a diet rich in plant-based fiber changes the composition of the intestinal microbiome by eating the right kind of bacteria … especially by producing short-chain fatty acids. Faecalibacterium prausnitzii, [which] offer many metabolic benefits, including weight loss, increased insulin sensitivity and fat loss, including visceral fat loss, "she noted.
However, Emma Elvin, a senior clinical advisor at Diabetes UK, warned that "further research was needed" to understand how plant-based diets affect the gut microbiota and, most importantly, what are the distinct effects of the specifically vegan diet compared to its calorie reduction before recommending the widespread adoption of a vegan approach. "
"It is true that many foods in a balanced vegan diet are good for us, but that does not mean that all vegan diets are in good health," she added.
"That being said, evidence to date has shown that some foods in herbal diets – such as fruits, vegetables and whole grains – were associated with reduced risk of type 2 diabetes."
Modifications of the intestinal microbiome of the vegan diet to the daily regime
For the study, 148 overweight / obese adults with no history of diabetes were randomized to follow a low fat vegan diet (n = 73) or no dietary change (n = 75). The average age in the vegan and control groups was 53 years and 57 years, respectively; 60% and 67% were women, respectively; and the body mass index was about 33 kg / m3 in both groups.
The vegan diet contained no animal products and included legumes, nuts, vegetables, fruits and whole grains. Caloric intake was unrestricted in both groups.
The purpose of the study was to test the effect of the vegan-based plant diet on gut microbiota composition, body weight, body composition and insulin sensitivity during 16 weeks.
"We were interested in the metabolic results," said Kahleova.
"We've known for a long time that herbal diets are very effective for weight management, because unlike many diets, the vegan diet is sustainable in the long run and the benefits go beyond the immediate intervention In comparison, the keto diet, for example, is good as long as you're there, but people come out and take over weight. "
However, she added that, to this day, the mechanisms behind the benefits of a vegan diet were poorly understood, what this study and others are intended to illuminate.
F. prausnitzii Feed on fiber and cause fat loss, including visceral fat
In evaluating participants' intestinal microbiome composition, Kahleova and colleagues found that the entire family of bacteroids was increased in those who followed a vegan diet.
And one species proved particularly important – Faecalibacterium prausnitzii. "The relative abundance of F. prausnitzii increased in the vegan group and was associated with a therapeutic effect of + 4.8%, "said Kahleova.
"Lower counts of these bacteria have been reported in diabetic patients, which has been associated with resistance to insulin and inflammation," she added.
F. prausnitzii produces short-chain fatty acids, which have many metabolic benefits, including the prevention of cardiovascular disease, insulin-sensitizing effects and positive effects on the immune system.
These short-chain fatty acids are produced by these bacteria, which feed on abundant fiber in plant-based foods but not in products of animal origin. "The more plants eat, the more these bacteria are fed and the more amount of short-chain fatty acids produced is important," Kahleova explained.
"The increase of F. prausnitzii observed in our study correlates with weight loss and increased sensitivity to insulin, "she said.
And most importantly, two-thirds of the weight loss was "explained by fat loss," she noted, adding that "visceral fat was also easily lost with the vegan diet."
Vegan diet versus vegetarian and the challenges of being vegan
Previous studies have shown that vegans have a lower risk of diabetes than vegetarians, Kahleova said. A vegetarian diet is more liberal and can contain a lot of saturated fat, she noted.
But she acknowledged that switching to a vegan diet is not without challenges.
"It can be difficult at first, for example, to find and prepare recipes, as well as to eat in restaurants, we often eat the same things as we do, or we have to cook for our families," she said.
She also warned of a decline in vitamin B12 levels that can be associated with a vegan diet.
Diabetic patients taking metformin (which also reduces vitamin B12) and in particular the elderly (taking metformin or not) may have vitamin B12 deficiency and these people may need to take supplements. she advised.
Kahleova said that among his future research projects, there was a cross-over trial of a low-fat vegan diet with a restricted carbohydrate diet and portion-controlled, recommended by the American Diabetes Association ( ADA) for diabetic patients. The composition of the intestinal microbiome will be measured.
"We are also conducting another study comparing a low-fat vegan diet to a Mediterranean diet rich in olive oil and nuts, which will address the quality and amount of fat in each diet. In the future we could compare vegan diets with low fat and vegan high fat. "
The study was funded by the Physicians Committee for Responsible Medicine. Kahleova has not reported any relevant financial relationship.
Annual Meeting of EASD 2019. Presented 19 September 2019. Summary 700.
For more information on diabetes and endocrinology, follow us on Twitter and Facebook.
[ad_2]
Source link