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TalkingNutrition

Providing perspectives on recent research into vitamins and nutritionals

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Choices in Nutrition: What Will You Decide?

By Julia Bird

In nutrition, it seems like we are often presented with lifestyle changes that involve two or more seemingly opposing choices. These can be argued passionately, with advocates on both sides producing compelling arguments. Some examples of common nutrition conundrums:

 * Is reducing calorie intakes or increasing physical activity for weight loss more effective?

 * Is it healthier to reduce sugar or fat in the diet?

 * Does one take a calcium and vitamin D supplement, or take up resistance exercise to prevent osteoporosis?

 * Should pregnant women take a folate supplement or change their diet to increase folate intakes?

The recent publication by Faghihzadeh and colleagues looks at another option: the effect of general healthy eating and lifestyle counselling on non-alcoholic fatty liver disease patients, with or without resveratrol supplementation. Non-alcoholic fatty liver disease is one in which patients have low or zero alcohol consumption, yet develop a fatty liver. This fat causes liver inflammation and scarring, which can eventually lead to liver failure. Risk factors are associated with obesity and include adiposity, type II diabetes, high cholesterol levels, sleep apnea and an underactive thyroid. Prevention and treatment measures focus on a healthy diet, weight loss and regular exercise as there is no direct medication to treat the condition.

One agent that is being researched for its possible protective role on the liver in the obese is resveratrol. A pivotal article published in Nature by Baur and associates found that resveratrol caused changes in gene expression that prevented negative effects of obesity on mice, and thus extended their lifespan. More recently, resveratrol has found to specifically protect organs such as the liver and kidneys in animal models of obesity, such as that described by Schmatz et al.

In the current study, 50 men and women with non-alcoholic liver disease were provided standard dietary and lifestyle counselling. Half were randomized to a resveratrol supplement (500 mg trans-resveratrol once per day) and half to placebo, for 12 weeks.

The results showed that both groups reduced their body weight, BMI and waist circumference modestly during the trial. Waist circumference in particular was reduced by 7.5% in the resveratrol group compared to 0.5% in the control group, and total calorie intake was also reduced by 9.5% in the resveratrol group compared to 4.0%  in the control group; both were statistically non-significant but noteworthy. The researchers found that there were differences in markers of inflammation. All markers of inflammation measured (C-reactive protein, interleukin-6, tumor necrosis factor alpha, nuclear factor k-B, and cytokeratin 18) were significantly reduced in the resveratrol group, whereas there were only a few non-significant trends in the placebo group. In addition, levels of the liver enzyme alanine aminotransferase (ALT), a marker of liver damage, were reduced both groups, but the reductions were more pronounced in resveratrol group and significantly different to the reductions in the placebo group. These results were supported by liver examination by ultrasound. Patients taking resveratrol were more likely to receive a lower liver steatosis grade (steatosis is the process of fatty degeneration of the liver) than subjects in the control group. The results show overall that resveratrol has potential in reducing levels of inflammation and reducing liver damage in non-alcoholic fatty liver disease, in addition to lifestyle changes. More testing is clearly needed to establish resveratrol’s long term safety and efficacy in treating non-alcholic fatty liver disease.

To get back to my original question: which course of action is better? This study shows that the combination of both lifestyle changes and resveratrol was the most effective combination. For the other nutritional problems that I posed, the actions can be undertaken in parallel. Why waste time arguing that one approach is superior? Implementing both options is best.

 

Main citation:

Forouzan Forouzan Faghihzadeh, Peyman Adibi, Rahmatollah Rafiei, Azita Hekmatdoost, Resveratrol Supplementation Improves Inflammatory Biomarkers in patients with Nonalcoholic Fatty Liver Disease, Nutrition Research, Available online 23 September 2014, ISSN 0271-5317, http://dx.doi.org/10.1016/j.nutres.2014.09.005

Supporting citations:

Baur JA, Pearson KJ, Price NL, Jamieson HA, Lerin C, Kalra A, Prabhu VV, Allard JS, Lopez-Lluch G, Lewis K, et al. Resveratrol improves health and survival of mice on a high-calorie diet. Nature 2006;444(7117):337-42. http://www.nature.com/nature/journal/v444/n7117/suppinfo/nature05354_S1.html

Schmatz R, Perreira LB, Stefanello N, Mazzanti C, Spanevello R, Gutierres J, Bagatini M, Martins CC, Abdalla FH, Daci da Silva Serres J, Zanini D, Vieira JM, Cardoso AM, Schetinger MR, Morsch VM. Effects of resveratrol on biomarkers of oxidative stress and on the activity of delta aminolevulinic acid dehydratase in liver and kidney of streptozotocin-induced diabetic rats. Biochimie. 2012 Feb;94(2):374-83. doi: 10.1016/j.biochi.2011.08.005. Epub 2011 Aug 16.


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