CD36 and the Genetics of Fat Taste
Your ability to taste dietary fat is not just a matter of preference — it is
partly encoded in your DNA. CD3611 CD36
Also called fatty acid translocase or FAT; a
scavenger receptor protein expressed on platelets, macrophages, adipocytes,
intestinal enterocytes, and taste receptor cells
is expressed on the taste bud cells of the circumvallate papillae at the back
of the tongue, where it acts as the primary sensor for long-chain fatty acids
in food. rs3212018 is a 16-base-pair deletion in the 3' untranslated region
of the CD36 gene — a regulatory region that influences how much CD36 protein
a cell produces.
The Mechanism
The 3' untranslated region (3'UTR) of a gene is transcribed into mRNA but not translated into protein. Instead, it acts as a control switch: sequences in the 3'UTR govern mRNA stability, half-life, and translational efficiency. Deletions in this region can destabilize the mRNA transcript, reducing the amount of CD36 protein produced at the cell surface. For taste receptor cells, this means fewer CD36 receptors available to bind fatty acid molecules passing over the tongue. For intestinal enterocytes, fewer CD36 receptors may reduce chylomicron assembly and long-chain fatty acid absorption efficiency.
The deletion removes the sequence GCACAAATAAAGCACT at position 2070–2085 of the CD36 transcript. It lies in exon 14, the final exon of the gene, which contains the 3'UTR in CD36 transcripts. Unlike coding-region variants, this deletion does not change the amino acid sequence of the CD36 protein — its effect, if any, operates through altered mRNA abundance or stability.
The Evidence
The relationship between rs3212018 and fat perception is inconsistent across
populations, which is characteristic of 3'UTR regulatory variants whose
effects depend on tissue-specific co-factors. The
Keller et al. 2012 study22 Keller et al. 2012 study
Keller KL et al. Common variants in the CD36 gene
are associated with oral fat perception, fat preferences, and obesity in
African Americans. Obesity (Silver Spring), 2012
of 317 African-American adults genotyped five CD36 polymorphisms and reported
that rs3212018 was associated with BMI and waist circumference in this cohort.
However, a later
Czech young adult study33 Czech young adult study
Sedláčková P et al. The rs1527483, but not rs3212018,
CD36 polymorphism associates with linoleic acid detection and obesity in Czech
young adults. Br J Nutr, 2018
found no association between rs3212018 and fat taste threshold, BMI, or waist
circumference — with a significant finding only for the nearby rs1527483 variant.
The null result in Europeans is not surprising given the deletion allele
frequency is roughly 15% in Europeans versus approximately 6% in Africans;
sample sizes in individual studies may be insufficient for reliable detection
of the variant's effect in either direction. Evidence supporting a mechanistic
role for the 3'UTR in CD36 expression regulation comes from broader functional
studies: CD36 mRNA levels are regulated by dietary fat intake in both lingual
and intestinal tissue44 CD36 mRNA levels are regulated by dietary fat intake in both lingual
and intestinal tissue
Gaillard D et al. CD36 gene deletion reduces fat
preference and intake but not post-oral fat conditioning in mice.
Am J Physiol Regul Integr Comp Physiol, 2007,
and altered mRNA stability would logically shift the set point of this
regulation. Overall, the evidence places this variant at the emerging level:
biologically plausible, population-specific signals, but not yet replicated
consistently across independent studies.
Practical Actions
Carriers of the deletion allele (ID or DD genotype) may have modestly reduced CD36 expression at lingual taste receptor cells, potentially blunting perception of fat in food. This could reduce the satiety signal generated when long-chain fatty acids bind lingual CD36 — a signal that normally contributes to caloric regulation by informing the brain about fat content before digestion is complete. People with reduced fat taste sensitivity may underestimate the caloric density of fatty foods or require higher fat content to feel satiated.
Monitoring dietary fat intake objectively (via food logging or periodic dietitian review) can compensate for a potentially blunted sensory signal. Choosing fat sources that deliver strong non-taste cues — such as whole nuts, oily fish, or avocado rather than added oils or spreads — provides additional texture and satiety information beyond lingual CD36 sensing.
Interactions
rs3212018 is one of several CD36 variants studied in the context of fat perception. The most thoroughly evidenced is rs1761667 (CD36 G/A, 5'UTR promoter variant)55 rs1761667 (CD36 G/A, 5'UTR promoter variant), which consistently reduces CD36 expression and fat taste sensitivity across multiple populations and is in the GeneOps database. rs1527483 (intron 12 variant) showed association with fat taste threshold and BMI in Europeans. rs3840546 (another CD36 insertion/deletion) has been associated with BMI in African Americans. Individuals carrying multiple CD36 low-expression alleles across these independent variants may have a compounded reduction in fat taste sensitivity; this interaction has not been formally tested but follows logically from the additive effect model of regulatory variation.