Can diet reduce your thyroid antibodies? A group of Italian researchers has recently published a study about the effects of nutrition on Hashimoto’s, and they say “Yes!”
Over the course of 3 weeks, 180 people with Hashimoto’s were randomized to receive the study diet vs. a standard low-calorie diet. 108 patients ate the study diet, while 72 patients served as the control group and followed a low-calorie diet without any food restrictions or guidelines. Thyroid antibodies (Thyroid Peroxidase antibodies (TPO antibodies), Thyroglobulin antibodies (TG antibodies) and anti-microsomal antibodies), TSH, free T3, free T4 as well as body weight, mass, and composition was measured before the start of the study and after the study ended 3 weeks later in both the study group and the control group.
Thyroid antibodies (Thyroid Peroxidase antibodies (TPO antibodies), Thyroglobulin antibodies (TG antibodies) and anti-microsomal antibodies), TSH, free T3, free T4 as well as body weight, mass, and composition was measured before the start of the study and after the study ended 3 weeks later in both the study group and the control group.
Here Are the Results of the Study
Get this… after just 21 days, all the patients in the study group showed a significant decrease in the levels of thyroid antibodies, which are known to indicate how aggressive the attack is on the thyroid gland!! (The higher the antibodies, the more aggressive the attack, and I consider a drop of 10% or more an improvement!) This means that their condition was getting better!!
- Thyroglobulin (TG) antibodies dropped by 40% (−40%, P<−0.013)
- Thyroid Peroxidase (TPO) antibodies dropped by 44% (−44%, P< 0.029) Anti-microsomal antibodies dropped by 57%!! (−57%, P< 0.000)
In contrast, the people following the “normal diet” saw an increase in thyroid antibody markers!! This means that their condition was worsening…
- Thyroglobulin (TG) antibodies increased by 9% (+9%, P<0.017)
- Thyroid Peroxidase (TPO) antibodies increased by 16% (+16%, P<0.004) Anti-microsomal antibodies increased by 30%!! (+30%, P<0.028)
After 21 days, the study patients showed a slight decrease in body weight, body mass index and lost fat mass! “With regard to the body parameters measured in patients who followed this diet, reduction in body weight (-5%, P<0.000) and body mass index (-4%, P<0.000) were observed.”
Do You Want to Know More About the Diet??
Here are the specifics of the study diet:
Low carbohydrate – The study diet program was based on the following guidelines: 12-15% carbohydrates, *50-60% proteins, and *25-30% fats (the standard Western diet contains 50% carbohydrates, 15% proteins, and 35% fats.
Veggie rich – Patients were told to eat vegetables, including large leafy greens (but to exclude goitrogens, see below).
Meats – Patients were told to eat only lean parts of red and white meat and were also allowed to eat fish.
Excluded goitrogens – The authors quoted the following foods as goitrogenic: “cruciferous [vegetables] (Brassicaceae) family (rapeseed or canola, cabbage, turnip, watercress, arugula, radish, horseradish), milk, soy, spinach, millet, tapioca, and lettuce. Even certain food additives, i.e., nitrates used for fish and meat preservation [were considered goitrogens].”
Also excluded – eggs, legumes, dairy products, bread, pasta, fruit, and rice.
*I usually recommend a higher fat and lower protein ratio for people with Hashimoto’s and have reached out to the authors of the study to clarify the ratios as well as some other info but have not heard back. One of my readers, Anasuya Basil, a certified nutrition consultant mentioned that she believed the protein and fat ratios may have been accidentally switched by the authors of the paper. Per Anasuya “When I try to create a meal plan with the macronutrient %s that is recommended I find that this would effectively cut out nuts and seeds because that easily boosts the fat % well over 25-30%. Given that this diet already excludes grains and legumes, it would be harder to get adequate fiber without nuts and seeds. Vegetables are not high in fiber relative to grains/legumes/nuts and seeds. I suppose you could include berries and figs to get that fiber, but this is very limiting.”
The Root Cause Approach
I was really excited to see that a diet very similar to what I’ve been recommending since 2012 now has research to back it up!!
If you’re new to my work, here are my dietary guidelines in a nutshell that align with the study
I always advocate for a diet that is gluten free (due to sensitivity in up to 88% of people with Hashimoto’s), free of soy, canola, and rapeseed, due to potential goitrogenic properties that have been found to be an issue in Hashimoto’s.
I also recommend avoiding dairy products (not due to goitrogen content, but rather due to dairy protein sensitivity that is present in up to 80% of people with Hashimoto’s). It’s best to eat nitrate free meats when possible and limit processed foods and meats in general.
In many cases, I suggest an Autoimmune Paleo diet (excludes grains like rice and corn, excludes legumes and eggs in addition to nuts and seeds). I will often recommend staying off millet for advanced cases of Hashimoto’s, as it is a seed which can be reactive in some, with tapioca/cassava I urge moderation due to starchy content. In some cases, I may also recommend a restriction of fruit.
Differences Between the Study and My Recommendations
I previously wrote a post about goitrogens—a goitrogen is any substance that interferes with thyroid function—the tricky part is that not all of them are created equally, and not all of them work in the same way. Overall, my position on goitrogens in the crucifer family like broccoli, cabbage, turnip and the like has been that they are healthy for most people with Hashimoto’s and that they help the body detoxify, especially when cooked, fermented or lightly steamed, but even in their raw state. I have not seen issues with cruciferous vegetables in most clients, with the exception of those with small intestinal bacterial overgrowth (SIBO) (because crucifers are high in FODMAPs, which aggravate SIBO), and in those with the CBS genetic mutation (due to the high sulfur content of crucifers).
Lettuce is hardly ever something I recommend avoiding, with the exception of some cases of irritable bowel syndrome, as any raw veggies can aggravate IBS and we know that lettuce is not exactly a cookable thing 😉
Fat vs. protein vs. carb ratios – I often have people play around with their fat to protein to carb ratios to eat what fits them best. Some people (especially if they’re more active) will benefit from more proteins. Others benefit from more fats, such as those with brain fog, pain, and depression. Some may even benefit from ketosis. Personally, for me, lower carbs, higher fats, and ketosis made me feel amazing for a couple of years until I hit a plateau and then needed to add back more carbs to feel my best. The bottom line is that you have to adjust the diet to your needs and your needs may change!
Critique of the Study
It’s difficult to tell whether the carb restriction, goitrogen restriction, avoiding highly reactive foods (gluten, dairy, soy, eggs), or all of the above, played a role in improving patient outcomes.
I personally have seen similar results with thyroid antibodies reducing—and sometimes going away—and symptoms like fatigue, brain fog, anxiety, IBS and pain virtually disappearing and weight and hair loss beginning to decline in as little as three weeks with carb restriction and avoiding reactive foods! I am not sure what role goitrogens play at this point… If you are already eating low carb and avoid reactive foods and are interested in being a “guinea pig” for three weeks and also remove goitrogens, I’d love for you to report back to me on what results you found!
I would love to see a study that isolated goitrogens vs. low carb diet vs. allergen avoidance. Until then, I’m happy with the interest in this direction and will look forward to hearing from my fellow root cause rebels who decide to take on the guinea pig challenge.
I wish that the control group was an actual control group (the control group should have kept eating their “normal” diet), and I also wish that low-calorie was defined. How low are we talking? 800 Calories? 1200 Calories? 1500 Calories?? Obviously, there’s a big difference between 800 and 1500 Calories!
There was very little talk about adherence. Were the study participants actually following the diet they were told to follow? Was the control group actually eating low calorie? (adherence is a challenge for many studies of this sort).
Another critique of this study is that I wish the study had been done for at least 3 months, as that is the time needed to see the full effect on thyroid antibody markers!
**In reading the introduction and conclusion, it seems that the patients following the low-carb, low-goitrogenic diet saw a reduction in thyroid antibodies and weight markers. However, in reading the results, it looks as though the low-calorie group lost the weight? In my experience, losing weight in either scenario is going to happen, at least within three weeks (those in the low-calorie group are more likely to gain it back, while the ones in low-carb group won’t gain the weight back but may eventually plateau if their adrenals are still out of balance -> 90% of people with Hashimoto’s have some degree of adrenal dysfunction in my practice -> Here’s a post about adrenals). I’ve reached out to the researchers for clarification.
Additionally, it would have been great to track patient symptoms in addition to weight because, after all, we all want not just to look better but also feel better!!
Busting Common Hashimoto’s Diet Myths…
I’m really excited that this diet is busting common Hashimoto’s diet myths.
Some people think that going gluten free is only beneficial in people who have both Hashimoto’s and Celiac disease, but none of the patients in this study were found to have Celiac disease! All of them did have Hashimoto’s, and all of the patients who followed the study diet had a reduction in thyroid antibodies!
Many people with Hashimoto’s are also dairy sensitivity (up to 80% felt better in my survey). Interestingly, the study reported that 83% of people with thyroid antibodies had a deficiency in lactase, which is an enzyme that digests lactose in milk. In my experience, the casein in milk is more of a problem than the lactose, however.
Have you heard the myth that a low carbohydrate diet is “bad” for Hashimoto’s? Again, this is a common myth, but this study has shown that this is not the case and that low-carb is actually beneficial. Furthermore, I’m excited to see evidence that supports eating proteins and fats 🙂
So what about the goitrogen myth? I still hold my original stance but am willing to re-evaluate this position given more evidence. If you are already eating low carb and avoid reactive foods and are interested in being a “guinea pig” for three weeks and also remove goitrogens, I’d love for you to report back to me on what results you found… because after all, how you feel is most important!!
If you would like to reduce your TPO antibodies, reduce your TG antibodies and feel better (and potentially lose up to 5% of your weight), try the following plan for three weeks!
- Free of highly reactive foods (gluten, grains, eggs, soy, dairy, legumes)
- Low carbohydrate diet (low in fruit too!)
- Rich in veggies (maybe even limit goitrogens?)
To help get you started, download your free 2-Week AIP Recipe Plan below!
I hope this helps you on your journey!!