Dietary Supplements Research Update

Research news articles are produced to keep practitioners up to date on impactful research that is relevant to the field of integrative medicine. 

This issue includes recent large systematic reviews and meta-analyses on four common dietary supplements: Saccharomyces boulardii, magnesium, vitamin D, and omega-3 fatty acids. The following four article summaries examine whether or not:

• S. boulardii can help treat acute gastroenteritis in children
• Magnesium alone or in combination with other supplements can improve inflammation, oxidative stress, and metabolic parameters in individuals with polycystic ovarian syndrome (PCOS)
• Vitamin D supplementation can improve atopic dermatitis (eczema) in children with low serum vitamin D
• Omega-3 fatty acid supplementation can reduce the risk of major adverse cardiovascular events

Can Saccharomyces boulardii help treat acute gastroenteritis in children? (September 2022) 

Background

Acute gastroenteritis is gastrointestinal mucosal inflammation that causes diarrhea, vomiting, nausea, and abdominal pain. Pediatric gastroenteritis is a self-recovering condition, and oral rehydration can significantly decrease the course of the condition. However, despite its treatability, gastroenteritis is one of the largest factors leading to the “death burden” in children aged five and under. 

Randomized controlled trials (RCTs) have shown that the probiotic Saccharomyces boulardii can effectively shorten the duration of diarrhea in patients with acute gastroenteritis. 

Methods

The authors of this study performed a systematic review and meta-analysis to determine the safety and efficacy of S. boulardii in treating children (≤ five years old) with acute gastroenteritis. Specifically, the authors investigated the probiotic’s impact on the duration of diarrhea, the length of hospital stays, the number of bouts of diarrhea following the treatment, and the occurrence of adverse reactions. The systematic review and meta-analysis included ten RCTs, which included 1,282 children. 

Takeaways 

The authors found that compared to placebo or control groups, S. boulardii significantly decreased the length of both diarrhea (mean difference (MD) = 19.70) and hospitalization (MD = -0.91), and reduced the number of bouts of diarrhea following the treatment by 1.03 times.

The study also found no adverse reactions to the use of S. boulardii. Although further research is needed for confirmation, this systematic review and meta-analysis support the use of S. boulardii for treating pediatric gastroenteritis. (1) 

Can magnesium alone improve inflammation, oxidative stress, and metabolic parameters in individuals with polycystic ovarian syndrome (PCOS)? (August 2022) 

Background

PCOS is one of the most common endocrine disorders in females of reproductive age. In addition to fertility challenges, individuals with PCOS have an increased risk of cardiovascular disease, diabetes, and metabolic syndrome. 

Previous studies have shown that oxidative stress (OS), insulin resistance, and dyslipidemia are closely related to PCOS. (3) Additionally, a previously conducted systematic review suggested that OS may lead to the development of PCOS. (4)

Methods

The authors of this study performed a systematic review and meta-analysis to determine the efficacy of magnesium supplementation or co-supplementation on inflammatory markers (i.e., high-sensitivity C-reactive protein (hs-CRP)), OS (i.e., total antioxidant capacity and malondialdehyde), and metabolic parameters (i.e., glucose and lipid metabolism) in patients with PCOS.

The systematic review and meta-analysis included nine RCTs with a total of 363 participants.

Takeaways 

The authors found that magnesium supplementation alone did not improve inflammation, OS, or metabolic parameters in patients with PCOS.

Combining magnesium with vitamin E, zinc, or zinc-calcium-vitamin D significantly reduced serum hs-CRP but not OS. Compared to placebo, the combination of magnesium and melatonin did not significantly reduce insulin and HOMA-IR levels. However, levels were significantly reduced compared to baseline values.

Lastly, combining magnesium with vitamin E or zinc-calcium-vitamin D significantly reduced triglycerides (TG) and total cholesterol (TC) levels. However, there were no significant differences in high-density lipoprotein (HDL) or low-density lipoprotein (LDL) levels. The combination of magnesium-melatonin supplementation reduced TC and LDL.

Although promising, further research is required to confirm the benefits of magnesium alone or in combination with other supplements in patients with PCOS. (3)

Can Vitamin D supplementation improve atopic dermatitis in children with low serum vitamin D? (July 2022) 

Background

Atopic dermatitis (AD) is a common chronic and often recurring inflammatory skin disease which causes pruritus, eczema, and dry skin. AD affects 5 to 20% of children globally, and approximately 30% will continue to experience AD into adulthood. 

Previously conducted studies have found that vitamin D deficiency may play a role in the development of AD. Additionally, it has also been seen that AD symptoms improved with supplementation of vitamin D. 

Methods

The authors of the study conducted a systematic review and meta-analysis to further explore the relationship between vitamin D deficiency and AD. The review also analyzed the effectiveness of vitamin D supplementation on AD severity using the atopic dermatitis index (SCORAD) and eczema area and severity index (EASI). A total of 22 studies were included in the analysis. 

Takeaways 

The authors found the following:

• The risk of vitamin D deficiency in patients with AD was significantly higher than in healthy controls. 
• Vitamin D supplementation decreased the SCORAD scores significantly by 11 to 18.8 points.
• Compared to placebo, vitamin D supplementation significantly decreased the EASI scores by 3.72 points. 

The correlation between vitamin D deficiency and AD is not yet fully understood. However, this systematic review demonstrates not only that patients with AD have a higher risk of vitamin D deficiency but that supplementation may improve their symptoms. (2)

Can omega-3 fatty acid supplementation reduce the risk of major adverse cardiovascular events? (February 2022) 

Background

Omega-3 fatty acids (FAs) are polyunsaturated FAs commonly found in fish and have been associated with cardiovascular health. However, the clinical use of omega-3 fatty acids supplementation for the prevention and treatment of coronary heart disease (CHD) remains controversial. 

Methods

The authors conducted a meta-analysis of RCTs which investigated the effect of omega-3 FA supplementation on CHD. This meta-analysis included 14 clinical RCTs, with a total of 135,291 participants. In addition, the authors estimated the relative risk (RR) for the following cardiovascular events: all-cause mortality, major adverse cardiovascular events (MACEs), cardiovascular death, myocardial infarction (MI), stroke, and revascularization.

The study analyzed the link between cardiovascular risk and omega-3 FA supplementation in the total subjects and the subgroups (i.e., different stages of CHD, omega-3 FA supplementation dose, diabetes, and sex).

Takeaways 

The meta-analysis found that omega-3 FA supplementation can reduce the incidence of MACE, cardiovascular death, and MI by 5%, 6%, and 14%, respectively. The dose of omega-3 FA that was found to be the most beneficial in regards to CHD risk reduction was 0.8 to 1.2 g. This study suggests that omega-3 FA supplementation may be beneficial for those with CHD. (5)