The Scientific Basis for Supplementation for Disease

BCAAs for hepatic encephalopathy

Hepatic encephalopathy is a brain disorder caused by liver dysfunction and portal vein shunt. In this article, we will discuss the evidence that BCAAs can alleviate the symptoms of hepatic encephalopathy, a condition that can lead to coma in some cases. The following is an introduction to the evidence.

Research

We found 16 randomized clinical trials involving 827 participants with hepatic encephalopathy classified as overt (12 trials) or minimal (4 trials).

Eight trials evaluated oral BCAA supplementation and seven trials evaluated intravenous BCAAs. The control group received placebo/no intervention (2 trials), diet (10 trials), lactulose (2 trials), or neomycin (2 trials).

In 15 trials, all participants developed cirrhosis of the liver.

A meta-analysis of the variable effects on mortality found no difference between BCAAs and controls. No evidence of small study effects was found.

Conclusions 

In this updated review, we included five additional trials. The analysis showed that BCAAs have a beneficial effect on hepatic encephalopathy. There was no effect on mortality, quality of life, or nutritional parameters, but additional trials are needed to evaluate these results. Similarly, additional randomized clinical trials are needed to determine the effects of BCAAs compared to interventions such as non-absorbable disaccharides, rifaximin, or other antibiotics.

Gluud LL, Dam G, Les I, Marchesini G, Borre M, Aagaard NK, Vilstrup H. Branched-chain amino acids for people with hepatic encephalopathy Cochrane Database of Systematic Reviews 2017, Issue 5. art. No.: CD001939. doi: 10.1002 / 14651858.CD001939.pub4. 

Oral supplements for cystic fibrosis

Cystic fibrosis is an autosomal recessive genetic disease, which is caused by an unusual ability to transport chloride ions.

Cystic fibrosis is an incurable disease that causes respiratory problems due to the viscosity of secretions in the body. Since nutritional deficiency is also likely to occur in this condition, we will introduce the evidence on whether it can be improved by oral supplements. The following is an introduction to the evidence of this disease.

Study details

Twenty-one trials were identified, including three that reported results from 131 participants that lasted from three months to one year. Two trials compared supplementation to additional nutritional advice, and one compared it to no intervention. Two of the included trials recruited children only.

In one trial, the clinical status of the group appeared to be unevenly balanced at baseline, and in the other there were concerns about allocation concealment.

There were no significant differences in changes in weight, height, body mass index, z-score, or other indices of nutrition or growth among those who received only supplements or dietary advice.

Conclusion.

Oral calorie supplements do not confer any additional benefit to sole-supervised nutritional management over moderately malnourished children with cystic fibrosis and over the use of dietary advice. Dietary supplements may be used, but should not be viewed as essential. Further randomized controlled trials are needed to establish the role of short-term oral protein energy supplements in people with cystic fibrosis and acute weight loss, as well as for long-term nutritional management of adults with cystic fibrosis or advanced lung disease, or both.

Smyth RL, Rayner O. Oral caloric supplements for cystic fibrosis. cochrane Database of Systematic Reviews 2017, Issue 5. art. No.: CD000406. doi: 10.1002 / 14651858.CD000406.pub5. 

Zinc Supplementation for Tinnitus

There are many causes of tinnitus.

One of them is due to nutritional deficiencies, and it is also believed that a lack of zinc can cause tinnitus. This is because zinc plays a role in some physiological aspects of the ear. Here is some evidence on what actually happens when zinc is supplemented orally. Here is the evidence.

The study

We included three studies with a total of 209 participants.

These studies had a moderate to high risk of bias.

Improvement in tinnitus severity and disability

Only the study that included older patients used a validated instrument (Tinnitus Handicap Questionnaire) for this primary outcome.

The authors of this crossover study did not report the results of the two phases separately, and found no significant difference in the proportion of patients reporting improvement in tinnitus at four months of follow-up.

None of the included studies reported any significant adverse effects.

Secondary Outcomes

For the secondary outcome change in tinnitus volume, one study reported no significant difference between the zinc and placebo groups after 8 weeks. The authors of this second study reported no significant difference between the zinc group and the placebo group after four months.

Conclusion.

We found no evidence that the use of oral zinc supplements improves symptoms in adults with tinnitus.

Person OC, Puga MES, da Silva EMK, Torloni MR. zinc supplementation for tinnitus.Cochrane Database of Systematic Reviews 2016, Issue 11. art. No.: CD009832 DOI: 10.1002 / 14651858.CD009832.pub2. 

Vitamin D supplementation for the prevention of bone fractures

In a limited way, the risk of fracture is increased by the decrease in bone density due to osteoporosis and aging. My impression is that most people who have experienced a fracture are able to make efforts to prevent it, but the nutrients we consume on a daily basis may be enough to prevent it.

There are factors that can contribute to this, such as calcium and vitamin D. In this article, I will introduce the evidence of vitamin D supplements and how they can be taken. The following is an introduction to the evidence.

Study details

We included 53 studies with a total of 91,791 participants.

Thirty-one trials, with sample sizes ranging from 70 to 36,282 participants, looked at vitamin D with or without calcium (including 25-hydroxyvitamin D) in preventing fractures in community, nursing home, or inpatient populations. Twelve of these 31 trials had participants with a mean or median age of 80 years or older.

Another group of 22 smaller trials tested calcitriol or alfacalcidol (1-alpha hydroxyvitamin D3), mostly in participants who had developed osteoporosis.

These trials were conducted in an institutional referral clinic or hospital setting.

In assessing the risk of bias for random sequence generation, 21 trials were considered low risk, 28 trials were considered uncertain risk, and 4 trials were considered high risk. There is high quality evidence that vitamin D alone, in the form and dose tested, is not effective in preventing hip fractures.

There is high quality evidence that the combination of vitamin D and calcium slightly reduces the risk of hip fracture. There is high quality evidence that vitamin D and calcium are associated with a statistically significant reduction in the incidence of new non-vertebral fractures.

However, there is only moderate quality evidence showing that there is no statistically significant preventive effect on clinical vertebral fractures.

There is high quality evidence that the combination of vitamin D and calcium reduces the risk of all types of fractures.

Regarding the adverse effect results:.

Mortality was not adversely affected by either vitamin D or vitamin D and calcium supplementation. Hypercalcemia, usually mild (2.6-2.8 mmol/L), was more common in those receiving vitamin D or analogues, with or without calcium.

The risk of gastrointestinal symptoms was also slightly increased.

Conclusion.

Vitamin D alone is unlikely to prevent fractures at the doses and formulations tested to date in the elderly. Vitamin D and calcium supplementation can prevent hip and all types of fractures. There was a small but significant increase in gastrointestinal symptoms and renal disease associated with vitamin D and calcium. This review found no increased risk of death with calcium and vitamin D intake.

Avenell A, Mak JCS, O'Connell D. Vitamin D and vitamin D analogues for preventing fractures in postmenopausal women and older men. Cochrane Database of Systematic Reviews 2014, Issue 4. art. No.: CD000227. doi: 10.1002 / 14651858.CD000227.pub4. 

Vitamin supplementation and dementia

Study Description.

We included five trials with 879 participants that investigated vitamin B supplementation. In four trials, the intervention was a combination of vitamins B6, B12, and folate. In one, it was folic acid alone. The doses varied.

We considered that there was a risk of performance and attrition bias and selective reporting of results among these trials. The primary efficacy outcomes were the incidence of dementia and scores on measures of overall cognitive function.

No trials reported on the incidence of dementia, and the quality of evidence on overall cognitive function was very low.

There was probably little or no effect of vitamin B taken for 6 to 24 months on episodic memory, executive function, processing speed, or quality of life.

Evidence on other secondary clinical outcomes, including harm, was either very sparse or of very low quality. There was evidence from one study that brain atrophy may be slowed over two years in participants taking B vitamins.

The same study reported a subgroup analysis based on baseline levels of serum homocysteine (tHcy) and found evidence that vitamin B improved episodic memory in patients with tHcy above the median at baseline.

Conclusion.

Evidence regarding vitamin and mineral supplements as a treatment for MCI is very limited. Three years of treatment with high-dose vitamin E probably does not reduce the risk of progression to dementia, but there are no data on this outcome for other supplements. Only B vitamins have been evaluated in multiple RCTs; there is no evidence of a beneficial effect of vitamin B supplementation on cognition for months 6 to 24. Evidence from a single study on the beneficial effects of vitamin B on brain atrophy reduction in participants taking vitamin B and on episodic memory in those with high tHcy at baseline warrants an attempt at replication.

McCleery J, Abraham RP, Denton DA, Rutjes AWS, Chong LY, Al-Assaf AS, Griffith DJ, Rafeeq S, Yaman H, Malik MA, Di Nisio M, MartínezG Vernooij RWM, Tabet N. Prevention of dementia or delay of cognitive decline in people with mild cognitive impairment. Cochrane Database of Systematic Reviews 2018, Issue 11. Art. no.: CD011905. doi: 10.1002 / 14651858.CD011905.pub2.