Liver Disease, Obesity, and Essentiality of Vitamins
Obesity is associated with two metabolic aberrations. The most prevalent is metabolic syndrome, a cluster of disorders produced by a fatty liver, including elevated blood glucose and triglycerides. Non-alcoholic fatty liver disease (NAFLD) is defined by the accumulation of excess fat in the liver. There are no outward signs of NAFLD. Both metabolic syndrome and NAFLD contribute to non-alcoholic steatohepatitis (NASH) and other chronic diseases, e.g. type 2 diabetes, cardiovascular disease. All forms of NAFLD increase the risk of NASH, cirrhosis and liver cancer.
There is no established treatment although oxidative stress is known to play a central role in NASH. Sanyal and colleagues randomly assigned 247 adults with NASN and without diabetes to: 1) 800 IU vitamin E daily, 2) 30 mg pioglitazone daily, or 3) placebo for 96 weeks. A 43% improvement in histologic features of NASH was observed with vitamin E therapy (vs placebo, p = 0.001) but not with piogliatazone. Basically, increasing vitamin E intake was more effective than drugs.
The vitamin E requirement for adults is 15 mg daily. The average person consumes about half (7.5 mg) of this amount daily. Dr Danny Manor, associate professor at Case Western Reserve University, has suggested that suboptimal vitamin E intake could directly impact the lives of approximately 63 million Americans at risk of obesity-related liver disease.
Healthy men with NAFLD have been found to have lower vitamin D concentrations than age-matched controls even after adjusting for body mass index (BMI) and metabolic syndrome (Rhee et al, 2013). Jablonski et al (2012) reported that serum vitamin D levels were significantly lower in NAFLD patients.
While obesity increases risk of NASH, the associations of vitamins E and D with liver dysfunction confirm the importance of maintaining optimal micronutrient status, not just balancing caloric intake with physical energy expenditure, for long-term health. Counting calories isn’t sufficient. Choose nutrient dense foods, and use dietary supplements when appropriate, to obtain micronutrients essential for health.
Yki-Jarvinen H. Non-alcoholic fatty liver disease as a cause of metabolic syndrome. 2014 Lancet Diab Endocrinol doi: 10.1016/S2213-8587(14)70032-4
Pacana T, Sanyal AJ. Vitamin E and nonalcoholic fatty liver disease. 2012 Curr Opin Clin Nutr Metab Care doi:10.1097/MCO.0b13e328357f747
Sanyal AJ, Chalasani N, Kowdley KV, McCullough A, Diehl AM, Bass NM, Newschwander-Tetri BA, Lavine JE, Tonascia J, Unalp A, Van Natta M, Clark J, Brunt EM, Kleiner DE, Hoofnagle JH, Robuck PR. Prioglitazone, vitamin E, or placebo for nonalcoholic steatohepatitis. 2010 NEJM doi: 10.1056/NEJMoa0907929
Tao K, Shi K-H, Wu J-X, Zhan H-Y. Nonalcoholic fatty liver disease is a potential risk factor for cardiovascular diseases. 2014 Nutr Metab Cardiovas Dis doi: 10.10.1016/j.numecd.2013.04.012
Rhee EJ, Kim MK, Park SE, Park CY, Baek KH, Lee WY, Kang MI, Park SW, Kim SW, Oh KW. High serum vitamin D levels reduce the risk of nonalcoholic fatty acid disease in healthy men independent of metabolic syndrome. 2013 Endocrin J doi: 10.1507/endocrj.EJ12-02387
Jablonski KL, Jovanovich A, Holmen J, Tagher G, McFann K, Kendrick J, Chonchol M. Low 25-hydroxyvitamin D level is independently associated with non-alcoholic fatty liver disease. 2012 Nutr Metab Cardiov Dis doi: 10.1016/j.numecd.2012.12.006