Effects of almond consumption on metabolic function and liver fat in overweight and obese adults with elevated fasting blood glucose: A randomised controlled trial

Jane Bowen; Natalie D Luscombe-Marsh; Welma Stonehouse; Cuong Tran; Geraint B Rogers; Nathan Johnson; Campbell H Thompson; Grant D Brinkworth

doi:10.1016/j.clnesp.2018.12.088

Effects of almond consumption on metabolic function and liver fat in overweight and obese adults with elevated fasting blood glucose: A randomised controlled trial

Clin Nutr ESPEN. 2019 Apr:30:10-18. doi: 10.1016/j.clnesp.2018.12.088. Epub 2019 Jan 11.

Authors

Jane Bowen¹, Natalie D Luscombe-Marsh¹, Welma Stonehouse¹, Cuong Tran¹, Geraint B Rogers², Nathan Johnson³, Campbell H Thompson⁴, Grant D Brinkworth⁵

Affiliations

¹ Commonwealth Scientific and Industrial Research Organisation - Health and Biosecurity, PO Box 10041, Adelaide 5000, Australia.
² Microbiome Research, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide 5001, Australia.
³ Faculty of Health Sciences and Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, University of Sydney, Lidcombe 2141, Australia.
⁴ Discipline of Medicine, University of Adelaide, 5000, Australia.
⁵ Commonwealth Scientific and Industrial Research Organisation - Health and Biosecurity, Riverside Corporate Park, 11 Julius Avenue, North Ryde, 2113, Australia. Electronic address: grant.brinkworth@csiro.au.

PMID: 30904207
DOI: 10.1016/j.clnesp.2018.12.088

Abstract

Background: Almonds are a rich source of bioactive components. This study examined the effects of daily almond consumption on glycaemic regulation, liver fat concentration and function, adiposity, systemic inflammation and cardiometabolic health.

Methods: 76 adults with elevated risk of type 2 diabetes (T2D) or T2D (age: 60.7 ± 7.7 years, body mass index: 33.8 ± 5.6 kg/m²) were randomly assigned to daily consumption of either 2 servings of almonds (AS:56 g/day) or an isocaloric, higher carbohydrate biscuit snack (BS) for 8 weeks. Glycosylated haemoglobin (HbA1c), glycaemic variability (GV), liver fat, serum aminotransferases, body weight and composition, markers of cardio-metabolic risk and systemic inflammation were assessed at baseline and week 8.

Results: No group differential effects were observed on HbA1c, GV, body weight and composition, liver fat and aminotransferases, cardio-metabolic health and inflammatory markers (all P > 0.05). For serum TC/HDL-C ratio a significant gender × treatment × time interaction occurred (P < 0.01), such that in women TC/HDL-C ratio was significantly reduced after AS compared to BS (-0.36 [0.26] mmol/L [n = 14] vs. -0.14 [0.32] mmol/L [n = 17]; P = 0.05), but not in men (P = 0.52).

Conclusions: Compared to BS, AS consumed between meals did not substantially alter glycaemic regulation, liver fat or function, adiposity, and metabolic health and inflammatory markers. Serum TC/HDL-C ratio improved in women, but not in men with AS; but as this sub-analysis was not defined a priori the results should be interpreted with caution. Further research should examine the longer-term health effects of regular almond consumption and differential gender responses.

Clinical trial registry number and website: Australia New Zealand Clinical Trial Registry: ACTRN12616000571471 (https://www.anzctr.org.au).

Keywords: Adiposity; Diet; Glucose metabolism; Glucose variability; Inflammation; Lipids; Liver fat; Nuts; Obesity; Overweight.

Publication types

Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Blood Glucose
Diabetes Mellitus, Type 2*
Diet, Fat-Restricted*
Fatty Acids / blood
Female
Humans
Liver / metabolism*
Male
Middle Aged
Obesity, Morbid / blood
Obesity, Morbid / diet therapy*
Overweight / blood
Overweight / diet therapy
Prunus dulcis*
Treatment Outcome
Young Adult
alpha-Tocopherol / blood

Substances

Blood Glucose
Fatty Acids
alpha-Tocopherol

Associated data

ANZCTR/ACTRN12616000571471