Does keto cause hair loss?
by Vincent Sparagna |
Jun 10, 2019
Many wonder whether creatine causes hair loss, but there’s actually more evidence to suggest that keto causes hair loss.
Recently, Moreno et al. found that 29.6% of keto dieters reported hair fall at 4 months. Contrastingly, 0% of low-calorie dieters reported hair fall at any time during the study.
Interestingly, subjects were only keto for 30-45 days (4-6 weeks). Thus, greater hair fall (seen at 4 months) probably persisted from the ketogenic diet period, which ended over 2 months earlier.
However, only 7.4% of keto subjects reported hair fall one year, which suggests that hair might stop falling out ~10 months after reintroducing carbs. Nonetheless, subjects were only keto for 4-6 weeks, and 2 subjects still experienced hair fall at 12 months (i.e. 10 months later). Thus, hair fall may persist for many months after keto.
Now, we shouldn’t conclude anything about keto and balding yet. After all, this is only one study, and greater hair fall only causes hair loss if the lost hair is not replaced. Alas, Foster et al. actually found greater hair loss on keto.
Indeed, 35.1% of keto dieters lost hair after 6 months. Meanwhile, only 15.5% of low-fat subjects reported hair loss at month 6. This seemingly matches Westman et al.’s findings, in which 10% of keto dieters reported hair loss after 6 months.
Of note, only 15% of keto dieters reported hair loss at 3 months, while 12.4% of low-fat subjects reported the same. Hence, it seems like hair loss was similar at month 3, and more subjects lost hair between months 3 and 6 on keto.
That said, we need to consider adherence to keto. All told, if subjects weren’t *actually* keto, then we can’t say that keto caused the observed hair loss. Looking at adherence, 63% of keto dieters tested positive for urinary ketones at 3 months, and 28% tested positive at 6 months.
As such, 23.8% of adherent keto dieters lost hair at 3 months, while ~50% reported hair loss at 6 months. Paradoxically, only 36 subjects stuck to keto by month 6, but 45 reported hair loss at this time. This matches Moreno’s finding on hair fall, which persisted ~1-2 months after a 4-6 week ketogenic diet stint.
So, it seems like more subjects noticed hair loss at 2-5 months after starting keto, and this loss persisted at month 6 (even though most subjects stopped following keto beforehand).
At one year, only 25.6% of keto dieters reported hair loss, which is a lower proportion than the 35.1% that noted hair loss 6 months earlier. Thus, some redeemed their lost hair over this this time period. However, this also means that ~72.9% of those who lost hair at 6 months, still hadn’t seen it return by month 12 (or that their hair returned, and 2 others lost hair).
To be fair, 16.5% of subjects in the low-fat diet group reported hair loss at month 12 as well. Hence, hair loss was only 55% more prevalent among keto dieters after 12 months.
Nevertheless, while 25.8% of all keto dieters still showed hair loss, only 14.3% of low-fat dieters reported hair loss at year 2. Therefore, hair loss seen with keto may persist for longer than that seen with a low-fat diet.
Otherwise, Goday et al. assessed hair loss among keto and low-calorie dieters with type 2 diabetes. This paper found hair loss in 5% of keto subjects at 4 months, and no hair loss among low-calorie dieters. However, the keto group also lost much more weight than the low-calorie group, so these findings are confounded.
In summary, 5-35% of keto dieters report hair fall/loss (at 3-21 months; after 1-5 months of keto). Meanwhile, just 0-16.5% of low-fat dieters report hair fall/loss, under the same conditions.
So, while data are quite limited, evidence suggests that hair fall/loss is more likely on keto. What’s more, roughly half of adherent dieters reported hair loss during/after keto (in Foster et al.). However, keto followers may not notice this hair fall/loss until ~2-5 months post-diet.
Why might keto cause hair loss?
First off, it’s not yet clear that keto causes hair loss. While keto may cause hair loss, it might just be a lurking variable (that coincides with the true cause of hair loss).
For example, energy restriction alone can cause hair loss. However, weight losses were similar between keto and non-keto diet groups in Foster’s study. Thus, greater hair loss on keto cannot be attributed to lower calorie intake among keto dieters.
However, weight loss was greater among keto dieters in Moreno’s study, so perhaps greater calorie restriction can explain the extra hair fall seen with keto.
Additionally, nutrient deficiencies can cause hair loss, and Calton found that Atkins dieters risk micronutrient deficiency. As such, some portion of keto dieters may have lost hair because they were nutrient-deficient, not because they were keto. Therefore, keto may only cause hair loss if it promotes a micronutrient deficiency. Yet, for this to be true, we’d need evidence to suggest that keto increases risk of micronutrient deficiency by more than a low-fat diet would.
Lastly, it’s not clear whether the ketogenic state of metabolism, or a lack of carbohydrates, would have more to do with hair loss (if either promotes hair loss at all).
All considered, if you maintain adequate micronutrient levels and calorie intake on keto, then you may not lose hair. Yet, if you want to minimize risk of hair loss, it’s probably best to avoid keto. However, many other factors influence hair loss, and not all keto dieters lose hair.
Moreover, only one good study has compared hair loss between keto and another diet, and this study found no statistical differences in hair loss between groups after 2 years (though, significantly more keto dieters lost hair throughout the study). Thus, even in the unlikely event that you lose hair on keto, you’ll probably see it return within 2 years.
If you found this post interesting, you’ll certainly enjoy the keto side effects article on sci-fit.net. We’re collecting and analyzing all of the data on ketogenic diets and their side effects, as compared to non-keto diets over time.
Keto studies that reported hair loss:
Moreno et al: https://www.researchgate.net/publication/260446326_Comparison_of_very_low-calorie_ketogenic_diet_with_a_standard_low-calorie_diet_in_the_treatment_of_obesity
Foster et al: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2949959/
Westman et al: https://www.ncbi.nlm.nih.gov/pubmed/12106620
This article is a guest blog post by Vincent Sparagna.
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