A randomized crossover study to assess the effect of an oat‐rich diet on glycaemic control, plasma lipids and postprandial glycaemia, inflammation and oxidative stress in Type 2 diabetes

Abstract

AimsIn the UK, lifestyle intervention is first-line management in Type 2 diabetes. It is unclear what type of diet is most efficacious for improving glycaemic control. This study investigated the effects of an oat-enriched diet on glycaemic control, postprandial glycaemia, inflammation and oxidative stress compared with standard dietary advice.MethodsIn a randomized crossover design, 27 volunteers with Type 2 diabetes, managed on diet and lifestyle only, were observed for two consecutive 8-week periods following either the oat-enriched diet or re-enforced standard dietary advice. Volunteers attended at baseline (habitual intake) and 8 and 16 weeks. Measurements included basic clinical measurements and fasted and postprandial (3-h) glucose and insulin in response to a healthy test meal. Markers of inflammation and oxidative stress, including high-sensitivity C-reactive protein, interleukin 6, interleukin 18, tumour necrosis factor-alpha, adiponectin, thiobarbituric acid reactive substances, oxygen radical antioxidant capacity, oxidized LDL and urinary isoprostanes, were also measured at fasting and in the postprandial period.ResultsThere were no diet-related effects on glycaemic control or glycaemic or insulinaemic responses to the test meal. Total cholesterol (5.1 ± 1.0 vs. 4.9 ± 0.8 mmol/l, P = 0.019) concentrations declined following the oat-enriched diet compared with standard dietary advice. There was a postprandial decline in adiponectin concentration (P = 0.009), but no effect of dietary intervention. None of the measures of oxidative stress or inflammation were altered by the oat-enriched diet compared with standard dietary advice.ConclusionThe oat-enriched diet had a modest impact on lipid lowering, but did not impact on oxidative stress or inflammation in these volunteers with Type 2 diabetes.

Oat‐enriched diet reduces inflammatory status assessed by circulating cell‐derived microparticle concentrations in type 2 diabetes

“…In agreement with data from the main study [43], there were no diet-related effects on glycemic control nor the glycemic or insulinemic responses to the test-meal for the current subpopulation (data not shown). In addition, neither oxidative stress or inflammation were altered between OAT and SDA (data not shown), again in agreement with the larger population [43]. Regression analysis (Table 6) showed that concentrations of total PMP were negatively associated with oxidized LDL (p = 0.041).…”

“…Although both OAT and SDA interventions failed to alter glycemia, inflammation, antioxidant capacity or oxidative stress , there were significant associations between certain of these indices and levels of MP, suggesting that the latter may provide sensitive markers to reflect subtle changes in additional health risks during the early stages of type 2 diabetes.…”

“…All volunteers had been offered advice on diet and lifestyle at diagnosis and had used this to control their diabetes without need for specific medication. At recruitment, fasting glucose and insulin were 7.7 mmol/L and 11.0 mU/L, with HOMA‐IR 3.9 . At entry to the study, subjects were following their habitual diet (HAB) and were randomly allocated to a cross‐over design with each arm of 8 wk that involved either their normal diet but with part of their carbohydrate intake substituted with a range of oat products (OAT) that were provided or by following a reinforcement of the SDA routinely offered at diagnosis and based predominantly on ‘‘Eating well with diabetes’’ provided by Diabetes UK.…”

Effect of Processing on Viscosity and Molecular Weight of (1,3)(1,4)‐β‐Glucan in Western Australian Oat Cultivars

“…Hence, it is important to determine the factors that influence the viscosity of b-glucan. Although many in vivo studies (Granfeldt et al 2008;Hlebowicz et al 2008;Charlton et al 2012;Zhang et al 2012;McGeoch et al 2013) have shown a positive influence of b-glucan from oat-incorporated products on health, the magnitude of this effect is variable and sometimes not significant (Lovegrove et al 2000;Chen et al 2006). External influences such as processing of food products prior to digestion might have an impact on the factors that affect b-glucan viscosity and, therefore, may have the potential to influence the physiological effects derived from b-glucan (Tosh et al 2008.…”

“…External influences such as processing of food products prior to digestion might have an impact on the factors that affect b-glucan viscosity and, therefore, may have the potential to influence the physiological effects derived from b-glucan (Tosh et al 2008. Although many in vivo studies (Granfeldt et al 2008;Hlebowicz et al 2008;Charlton et al 2012;Zhang et al 2012;McGeoch et al 2013) have shown a positive influence of b-glucan from oat-incorporated products on health, the magnitude of this effect is variable and sometimes not significant (Lovegrove et al 2000;Chen et al 2006).…”