Realistic changes in monounsaturated fatty acids and soluble fibers are able to improve glucose metabolism
Diabetology & Metabolic Syndrome
Realistic changes in monounsaturated fatty acids and soluble fibers are able to improve glucose metabolism
Camila Risso de Barros 0
Adriana Cezaretto 0
Mara Ladeia Rodrigues Curti 0
Milena Monfort Pires 0
Luciana Dias Folchetti 0
Antonela Siqueira-Catania 0
Sandra Roberta Gouvea Ferreira 0
0 Department of Epidemiology, School of Public Health, University of Sao Paulo , Sao Paulo , Brazil
Background/objectives: Cardioprotective effects of Mediterranean-style diet have been shown. Instead of excluding foods, replacement or addition may facilitate compliance with impact on glucose metabolism of individuals at cardiometabolic risk. This study investigated the effect of changing selected nutrients intake on glucose metabolism during a lifestyle intervention tailored to living conditions of prediabetic Brazilians. Subjects/methods: 183 prediabetic adults treated under the Brazilian public health system underwent an 18-month intervention on diet and physical activity. Dietary counseling focused on reducing saturated fat replaced by unsaturated fatty acids. Data were collected at baseline and after follow-up. ANOVA and multiple linear regression were used to test association of changes in nutrients intake with changes in plasma glucose. Results: Changes in fasting and 2-h plasma glucose but not in weight, HOMA-IR or C-reactive protein decreased after intervention across tertiles of MUFA changes (p-trend 0.017 and 0.024, respectively). Regression models showed that increase in MUFA intake was independently associated with reduction in fasting ( -1.475, p = 0.008) and 2-h plasma glucose ( -3.321, p = 0.007). Moreover, increase in soluble fibers intake was associated with decrease in fasting plasma glucose ( -1.579, p = 0.038). Adjustment for anthropometric measurements did not change the results but did after including change in insulin in the models. Conclusions: Increases of MUFA and soluble fibers intakes promote benefits on glucose metabolism, independently of adiposity, during a realistic lifestyle intervention in at-risk individuals. Mechanisms mediating these processes may include mainly insulin sensitivity improvement.
Monounsaturated fatty acids; Fiber intake; Lifestyle intervention; Glucose metabolism
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Background
Obesity-related diseases, such as type 2 diabetes and
cardiovascular disease, are major preventable problems which
could be attenuated by a healthy diet and exercise [1,2].
However, long-term compliance with a healthy lifestyle is
a challenge, particularly in emerging countries, where
populations have less access to healthy foods, usually more
expensive, and fewer opportunities for exercising. Dietary
recommendations have emphasized reduction in fat
consumption and encouraged fiber intake [3]. The deleterious
effects of saturated fatty acids (SFA) on cardiovascular risk
profile obfuscated the benefits of unsaturated fat, whose
cardioprotective role has been reinforced in more recent
publications [4,5]. Observational studies reported lower
cardiovascular mortality rates in populations consuming
high proportions of dietary unsaturated fatty acids and
fibers [6]. Underlying mechanisms involve inflammatory
mediators which interfere in glucose metabolism [7].
However, a diet rich in MUFA did not improve insulin
sensitivity in healthy participants of a Nordic randomized
clinical trial, except for a subgroup with a total fat
intake < 37% of energy [8]. It remains unclear whether
beneficial effects on glucose metabolism are independent
of body weight [9,10]. Also, for cardiovascular prevention,
a mixture of soluble and insoluble fibers has been
recommended. High-fiber diets have been associated with
benefits on glucose and lipid metabolism and may lower
risk of cardiovascular events [11]. Observational and
prospective studies provided evidence of improvement
in insulin sensitivity [12,13] but the effect of fibers on
inflammatory process is not yet well established [14].
Efficacy of the PREDIMED diet on reducing weight
gain [15] and preventing cardiometabolic outcomes [16]
has motivated several countries to change their eating
habits. Low acceptance of this dietary pattern outside
Mediterranean region was described in a Northern
European population [17]. In Latinos living in South
America, a better compliance with a diet rich in vegetable
oil, whole grains, fruits and vegetables, could be expected
considering their ancestry and local food availability.
Effectiveness of interventions on quality of fat and
amount of dietary fiber, tailored to public health systems
of developing countries, was scarcely investigated. In
general, dietary interventions imply food restrictions; instead
of excluding foods, replacement or even addition may be a
better strategy to achieve metabolic benefits. We
hypothesized that realistic changes in Brazilian eating habits may
facilitate compliance with impact on glucose metabolism
of individuals at cardiometabolic risk. This study
investig (...truncated)