A Randomized Study of the Effects of Additional Fruit and Nuts Consumption on Hepatic Fat Content, Cardiovascular Risk Factors and Basal Metabolic Rate

Christian Agebratt; Edvin Ström; Thobias Romu; Olof Dahlqvist-Leinhard; Magnus Borga; Per Leandersson; Fredrik H Nystrom

doi:10.1371/journal.pone.0147149

A Randomized Study of the Effects of Additional Fruit and Nuts Consumption on Hepatic Fat Content, Cardiovascular Risk Factors and Basal Metabolic Rate

PLoS One. 2016 Jan 20;11(1):e0147149. doi: 10.1371/journal.pone.0147149. eCollection 2016.

Authors

Christian Agebratt¹, Edvin Ström¹, Thobias Romu^{2

3}, Olof Dahlqvist-Leinhard^{1

2}, Magnus Borga^{2

3}, Per Leandersson⁴, Fredrik H Nystrom¹

Affiliations

¹ Department of Medical and Health Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden.
² Center for Medical Image Science and Visualization, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden.
³ Department of Biomedical Engineering, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden.
⁴ Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden.

Abstract

Background: Fruit has since long been advocated as a healthy source of many nutrients, however, the high content of sugars in fruit might be a concern.

Objectives: To study effects of an increased fruit intake compared with similar amount of extra calories from nuts in humans.

Methods: Thirty healthy non-obese participants were randomized to either supplement the diet with fruits or nuts, each at +7 kcal/kg bodyweight/day for two months. Major endpoints were change of hepatic fat content (HFC, by magnetic resonance imaging, MRI), basal metabolic rate (BMR, with indirect calorimetry) and cardiovascular risk markers.

Results: Weight gain was numerically similar in both groups although only statistically significant in the group randomized to nuts (fruit: from 22.15 ± 1.61 kg/m(2) to 22.30 ± 1.7 kg/m(2), p = 0.24 nuts: from 22.54 ± 2.26 kg/m(2) to 22.73 ± 2.28 kg/m(2), p = 0.045). On the other hand BMR increased in the nut group only (p = 0.028). Only the nut group reported a net increase of calories (from 2519 ± 721 kcal/day to 2763 ± 595 kcal/day, p = 0.035) according to 3-day food registrations. Despite an almost three-fold reported increased fructose-intake in the fruit group (from 9.1 ± 6.0 gram/day to 25.6 ± 9.6 gram/day, p<0.0001, nuts: from 12.4 ± 5.7 gram/day to 6.5 ± 5.3 gram/day, p = 0.007) there was no change of HFC. The numerical increase in fasting insulin was statistically significant only in the fruit group (from 7.73±3.1 mIE/L to 8.81±2.9 mIE/L, p = 0.018, nuts: from 7.29±2.9 mIE/L to 8.62±3.0 mIE/L, p = 0.14). Levels of vitamin C increased in both groups while α-tocopherol/cholesterol-ratio increased only in the fruit group.

Conclusions: Although BMR increased in the nut-group only this was not linked with differences in weight gain between groups which potentially could be explained by the lack of reported net caloric increase in the fruit group. In healthy non-obese individuals an increased fruit intake seems safe from cardiovascular risk perspective, including measurement of HFC by MRI.

Trial registration: ClinicalTrials.gov NCT02227511.

Publication types

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

MeSH terms

Adult
Basal Metabolism / drug effects*
Cardiovascular Diseases / etiology
Cardiovascular Diseases / pathology
Cardiovascular Diseases / prevention & control*
Diet*
Dietary Supplements
Fatty Liver / metabolism*
Feeding Behavior
Female
Follow-Up Studies
Fruit*
Humans
Male
Nuts*
Prognosis
Risk Factors
Young Adult

Associated data

ClinicalTrials.gov/NCT02227511

Grants and funding

The County Council of Östergötland and Linköping University, Department of Medical and Health Sciences, supported the trial with grants and other resources. The funders had no role in the design or completion of the trial.