Table 4.
Studies/reports on the relationship between consuming Hg-poor, omega-3-rich oily fish or by taking omega-3-based supplements and the clinical benefit towards thyroid autoimmune disorders. * §
| Reference | Methods and subjects studied | Main findings |
|---|---|---|
| Benvenga S et al. (17) | See above, Table 3. |
Fish consumption was quantitatively similar across groups, equivalent to an average of 7 to 8 times a month [see above, Table 3]. Positivity rates and serum levels of both TgAb and TPOAb were the lowest in group B and the highest in group A. For instance, TPOAb positivity at 1st, 2nd trimester of gestation, and day 4 postpartum was always 0% in group B, but 25%, 17%, and 12% in group A, with intermediate frequencies in groups C and D. Serum concentrations of both Ab were also the lowest in group B and the greatest in group B. The estimated content of mercury in the fish consumed monthly by the four groups was the lowest in group B and the highest in group A (approximately 25 and 1000 μg, respectively), with values of approximately 250 and 35 μg in groups C and D, respectively. In contrast, the estimated content of omega-3 fatty acids (EPA plus DHA) in the fish consumed monthly was the greatest in group B and the smallest in group A (13.2 ± 5.4 and 6.3 ± 2.1 g, respectively), with values of 6.0 ± 2.8 and 5.1 ± 3.8 g in groups C and D, respectively. |
| Benvenga S et al. (18) | See above, Table 3. | The four fish groups remained comparable in terms of frequency of fish consumption (7.5–8.0 times/month or twice a week) [see above, Table 3]. Results of frequency of positivity and serum concentration of either thyroid autoantibody (TgAb, TPOAb) confirmed those of the previous study. The lowest and the highest rates of detection of US signs of thyroiditis during pregnancy were detected in groups B and A (29.4 and 44.6%, respectively), with intermediate values in groups C and D. Overall, frequency of postpartum thyroiditis (PPT) was 15.3%. However, the smallest frequency was recorded in group B (4.7%) and the greatest in group B (23.9%), with intermediate rates in the other groups. Overall, the frequency of evolution of PPT into permanent hypothyroidism (PH) was 54%, with no difference between the four fish groups (50 to 56.2%), particularly between groups B and A (50% and 54.5%). |
| Breese McCoy, (130) | The author, an adjunct professor of physiology at Oklahoma State University, reports her self-treatment of postpartum Graves’ disease with flaxseed oil. | “Approximately one year into the propylthiouracil (PTU) treatment, I became aware that omega-3 fatty acids are thought to reduce the inflammation associated with certain autoimmune disorders, such as rheumatoid arthritis. … With this information in mind, I began a regimen of flaxseed oil supplements , 5-1,000 mg tablets twice a day. Flaxseed oil is over 50% omega-3 fatty acids (mainly alpha-linolenic acid), but it also contains about 15% omega-6 fatty acids (mainly linoleic acid). Within approximately eight weeks, TSH levels had normalized for the first time (0.31 µIU/mL, reference range 0.30-5.0). PTU was then discontinued, and flaxseed oil tapered to less than half the original dose, but TSH levels slipped below normal again within six months (0.29 uIU/mL, ref. range 0.35-5.00). Symptoms were mild , and T4 was within normal range (1.0 ng/dL, ref. range 0.7-1.9 ng/dL), so I declined to restart PTU therapy.” … The following year, she was pregnant again. “… by the fourth week postpartum, my TSH was again suppressed (0.174 µIU/mL, ref. range 0.30-5.00), becoming undetectable by four months postpartum. This time, however, plasma T4 remained within norma l range (1.7 ng/dL, ref. range 0.7-1.9 ng/dL). Although the physician advised me to take a low dose of PTU, I was experiencing no noticeable symptoms of hyperthyroidism and declined the prescription due to breastfeeding. As before, I then restarted a flaxseed regimen at about six months postpartum (this time, three tablespoons of whole seed on cereal each morning). My condition began improving , and plasma TSH normalized within six months (0.57 µIU/mL, ref. range 0.35-5.00). Flaxseed was then discontinued, and there has been no recurrence over the following four plus years”. |
| Dolan et al. (131) | Management, with omega 3 and other nutraceuticals, of a 34-yr-old Hashimoto’s thyroiditis woman who had declined thyroid replacement therapy. This patient, who was a part-time worker in a wellness clinic, also had a personal history of seasonal allergies, and a multigenerational history of thyroiditis and autoimmune disorders. In addition to supplementation and dietary changes, she performed two acupuncture treatments. |
Before being managed by the team, the patient self-prescribed a vegan diet and dietary supplements. Such supplements consisted of selenium (100-200 µg/day), iron, vitamin D3, probiotics, N-acetyl-L-cysteine. At the first visit, the patient reported feeling “ravenously hungry” having palpitations, bloating, low libido, low energy, cold hands and feet, and mental sluggishness. The authors switched her to nutritional supplementation of vitamins (B complex, D3), coenzyme Q10, α-lipoic acid, zinc, magnesium, omega-3 oil (DHA/EPA), L-glutamine, quercetin, and probiotics (50 billion live organisms from 14 strains) in conjunction with a customized herbal tincture [milky oat spikelet (A sativa), ashwagandha root (W somnifera), holy basil (O sanctum), damiana (T diffusa), cinnamon bark (Cinnamomum spp)] and a customized tea [chamomile flowering tops (M chamomilla), ginger (Z officinalis) rhizome, and agrimony (A eupatorium) herb]. Noteworthy, the vitamin B complex recommended, and to be taken once daily, contained 40 mg inositol. Furthermore, the patient was advised to avoid sensitive foods (gluten and soy) and increase her intake of berries, omega-3 rich foods (sardines, wild salmon, walnuts, organic flax), quality fats (organic: cold-pressed olive oil, coconut oils, butter or ghee), fermented foods (water, cultured coconut milk, kefir), and filtered water. Interpretation is complicated by the multitude of supplements, and by the lack of reference ranges for serum thyroid function tests (TSH, T4, FT4, T3, FT3) and autoantibodies (TgAb, TPOAb). However, serum TSH declined from the baseline level of 4. 91 µIU/ml to 1.62 at month 4 and 1.66 μIU/mL at month 12 post-treatment. The corresponding levels of FT4 were 1.13, 1.1, and 1.02 ng/dL, and those of FT3 were 3.1, 2.5, and 2.4 [no unit of measure provided, but it should be pg/ml]. Serum TgAb fell from 12.0 to 1.4 and 1.1 IU/mL; TPOAb fell from 258 to 115 and 24 IU/mL. In parallel with these biochemical changes, symptoms improved and had disappeared at the 8-month checkup. |
| Woźniak et al. (132)§ | 232 hypothyroid volunteers (age ≥18 years; median= 27 years; 203 women and 29 men) were asked to provide information on their diagnosis, clinical manifestations of the disease, lifestyles, and use of dietary supplements with effect on their health. Supplements were taken by 197/232, with information taken from websites (74%), physicians (52%), family/friends (46%) and social media (43%). |
Hashimoto’s thyroiditis was diagnosed in 49% of the 232 participants, with 93% taking L-T4. The most popular supplements taken were vitamin D (98%), magnesium (21%), omega-3 acids (15%), selenium (14%), multivitamins (14%), vitamin B (13%), iron (10%), vitamin C (9%) and zinc (8%). Supplements were taken for a median period of 1.5 years. The most common symptoms experienced included dry skin (64%), cold intolerance (58%), constipation (28%), somnolence (26%), fatigue (23%), hair loss (22%), headache (21%) and mood swings (14%). Patients were stratified into 8 categories based on the nutraceutical taken (vitamin D, vitamins B, iron, zinc, multivitamins, selenium, omega-3 acids), with data summarized as % of patients reporting a benefit for 8 items (decline of serum TSH, less fatigue, improved memory and concentration, improved hair and nails condition, improved skin condition, improved general well-being, better quality and longer sleep, alignment of menstrual cycles). Overall, 52% of those who took supplements reported health benefits. In regard to the omega-3 category, reported a benefit was improved hair and nails condition (2%), improved general well-being (8%), improved memory and concentration (13%), and a decline of TSH (2%). By comparison, selenium users reported a benefit for all items (2 to 8%) except the better quality and longer sleep (0%), while vitamin D users, vitamin B users and multivitamins users reported benefits for all 8 items (3 to 35%, 2 to 11%, and 4 to 16%, respectively). A decline of TSH occurred in each category (from 2% in the omega-3 to 7% in the vitamin D), except for iron (0%). |
*Keywords of relevance are highlighted by the bold-face print.
§For internal inconsistencies in the results reported by Woźniak et al, see text.