This week’s first study is a reminder that supplements may have a greater impact in certain circumstances than in others. The effectiveness of omega 3 supplements has been the topic of many discussions over the last 3 months, and I think it would be interesting if the meta-analysis that spurred the discussions had used the genetic data of the participants like the study below.
Omega 3 supplement effects vary by genotype. Replication of a Gene-Diet Interaction at CD36, NOS3 and PPARG in Response to Omega-3 Fatty Acid Supplements on Blood Lipids: A Double-Blind Randomized Controlled Trial. This study involved 185 people in China with Type 2 Diabetes and given either 2 g fish oil supplements, 2.5 g flaxseed oil supplements, or corn oil for 180 days. 150 of the participants also provided DNA samples to compare variants of the CD36, NOS3, and PPARG genes.
Some of the changes seen:
- For the CD36 gene, rs1527483-GG carriers saw a greater decrease in triglyceride levels while taking fish oil supplements than the A-allele carriers. The changes during supplementation were not significant for the control. The GG-allele decreases the activity of CD36 and the activity appears to be increased or partially restored by the omega-3 supplements.
- A subgroup of those that carry the NOS3 rs1799983 A-allele saw greater improvements in triglyceride and total cholesterol/HDL ratio with omega-3 supplements than CC-allele carriers.
- For the PPARG gene, rs1801282 GG/GC-allele carriers had a significantly higher increase in LDL cholesterol compared with CC carriers in the control group, but no difference was seen between the total omega-3, fish oil, or flaxseed oil groups.
None of the groups experienced any noted detriment to their lipid profiles while taking the omega-3 supplements. The authors point out that this study agrees with earlier studies that found the effects of omega-3 supplements on blood lipids vary by genetic variation of these three genes.
Curcumin may improve glucose utilization. Effects of Curcuminoids Plus Piperine on Glycemic, Hepatic and Inflammatory Biomarkers in Patients with Type 2 Diabetes Mellitus: A Randomized Double-Blind Placebo-Controlled Trial. One hundred people with Type 2 Diabetes were given dietary education plus either a placebo or curcumin supplement for 3 months. The curcumin supplement contained 500 mg/day curcuminoids and 5 mg/day of piperine. Even though curcumin is known for being anti-inflammatory, this study did not find a decrease in CRP levels in this group (CRP is one type of indicator of inflammation). The group that received the curcuminoids and piperine saw a greater decrease in glucose and HbA1C levels. There was also a decrease in C-peptide, indicating a decrease in insulin production.
Zinc may improve quality of life during menstrual cycle. Effect of zinc sulfate supplementation on premenstrual syndrome and health-related quality of life: Clinical randomized controlled trial. This research looked at 142 women with PMS, given either a placebo or 220 mg zinc sulfate (containing 50 mg elemental zinc) from the 16th day of the menstrual cycle to the second day of the next cycle for three months. The group receiving zinc sulfate saw improved PMS scores that continued to improve during the second and third months. The measurement of quality of life improved in the zinc sulfate group during the third and final month of the trial. The zinc sulfate was associated with less severe PMS and improved quality of life during PMS.