Can a Gene–Diet Mismatch Explain the Black–White IQ Gap Better Than Heredity?
Hereditarian explanations for the Black–White IQ gap are gaining traction. But what if there’s a better explanation, one grounded in biology, evolution, and diet?
This article addresses the toughest questions often raised by hereditarians and explains why the gene–diet mismatch hypothesis provides a more scientifically robust and humanistic explanation. The gene–diet mismatch hypothesis proposes that some populations (especially those with high prevalence of efficient FADS gene variants, such as people of African ancestry) have metabolic pathways that evolved under specific ancestral diets low in linoleic acid (LA) and rich in long-chain omega-3s like DHA. When these populations are exposed to modern, LA-heavy diets that lack DHA, it leads to an imbalance in the DHA/AA ratio and chronic inflammation.
Crucially, these individuals also tend to have narrower metabolic flexibility, meaning they are more easily shifted out of optimal biochemical ranges by diet. This makes it harder for them to buffer the harmful effects of suboptimal nutrition. The resulting chronic inflammation and disrupted nutrient metabolism can interfere with fetal brain development, reduce brain volume and myelination, impair synaptic plasticity, and weaken executive function. Over time, these physiological effects translate into poorer memory, lower attention span, and reduced cognitive capacity, which ultimately contribute to the observed gaps in IQ, academic achievement and dysfunctional behaviour.
Q1: Why does the Black–White IQ gap persist across generations, even with equal access to food, housing, & education?
A: Because equal access doesn’t mean optimal access.
Black Americans disproportionately carry efficient FADS1 gene variants, which convert linoleic acid (omega-6) into pro-inflammatory arachidonic acid (AA) more efficiently. In today’s high-LA, low-DHA food environment, this leads to chronic inflammation from birth.
Inflammation:
- Disrupts DHA metabolism (critical for brain development)
- Impairs nutrient absorption (e.g., vitamin D, magnesium)
- Affects sleep and executive function
All of which shape cognitive outcomes before a child ever enters school.
Q2: Why do we see IQ gaps at very young ages, even before school starts?
A: Because brain development is prenatal.
DHA, magnesium, choline, folate, iron and vitamin D (all essential for neurodevelopment) are depleted by inflammation. If a pregnant woman is inflamed due to a high-LA, low-DHA diet and carries efficient FADS genes, the fetus begins life at a neurological disadvantage.
Q3: Why are IQ gaps consistent across countries like the US, UK, and Canada?
A: Because the food system is global, and the mismatch is universal.
Wherever Black populations live, they tend to consume diets high in seed oils (LA) and low in DHA. Combined with efficient FADS variants, this creates a global, population-wide gene–diet mismatch that leads to systemic cognitive suppression.
Q4: Why don’t multivitamin or omega-3 studies show massive gains in Black participants?
A: Because the context matters.
Most studies:
- Don’t stratify by FADS genotype
- Don’t measure DHA/AA ratios
- Don’t control for inflammation or nutrient depletion
- Don’t measure omega-6 levels
- Don’t monitor whether the optimal DHA/AA ratio was achieved and maintained
Giving DHA to someone with an unresolved inflammatory load, nutrient deficiency, and disrupted DHA metabolism won’t yield large gains. This isn’t something a pill can fix, it’s a systemic problem.
Q5: If the IQ gap was environmental, wouldn’t it have closed by now?
A: It has in some populations. The ones without the gene-diet mismatch.
For example, East Asians or European immigrants closed the gap once they accessed stable resources and education. But for Black populations with a biological incompatibility with the modern food environment, the gap won’t close until the environment matches their biology.
Q6: Why do Black children of wealthy, educated mothers still score lower than White children of poorer, less-educated mothers?
A: Because wealth doesn’t reverse inflammation.
If the mother consumes a diet rich in seed oils and low in DHA and carries efficient FADS genes, her pregnancy is still inflammatory.
The child starts life depleted in key brain-building nutrients. No amount of postnatal tutoring makes up for that.
Q7: Why do Black children regress more from high-performing parents than White children?
A: It’s not regression to the mean as much as it’s prenatal suppression.
The child never got to express their full genetic potential because brain development was compromised in utero.
Q8: What about adoption? Why do adopted Black children raised in wealthy White families still show IQ gaps?
A: Because the mismatch starts in the womb.
Adoption can’t reverse prenatal depletion.
If a child was born to a mother with chronic inflammation, poor DHA status, and nutrient deficiencies, they may already have reduced brain volume and altered white matter development. So even though they may get a cognitive boost due to being raised in a stable home and exposure to mental stimulation, the underlying issue of gene-diet mismatch is unlikely to be addressed.
Q9: Why are twin IQs so similar, even when raised apart?
A: Because they shared the same prenatal environment.
If their mother was inflamed, had poor DHA status, or nutrient depletion, that environment shaped both twins identically — creating a persistent IQ “ceiling.” Also, irrespective of where a child is raised, they will both likely be exposed to the same food environment, one that is LA heavy and DHA light.
Q10: Why do adopted children resemble their biological parents more than their adoptive parents in IQ?
A: Because prenatal conditions and gene–diet interactions shape brain development.
Like obesity, cognitive traits are deeply influenced by the in utero environment. Even with different parenting, the biochemical programming from pregnancy persists. And very much analogous to obesity, cognitive traits are not a genetic destiny, but rather a reflection of gene-environment interactions.
Q11: Why might a child born to a starving North Korean mother have a higher IQ than a child born to a well-fed Black mother in America?
A: Because undernutrition ≠ inflammation.
Humans are evolutionarily adapted to periods of starvation, and starvation does not necessarily cause inflammation. In fact, inflammation may be worse than starvation in terms of cognitive-developmental harm.
A starving mother may still maintain a favourable DHA/AA ratio. The body in starvation mode may even operate in a more evolutionarily “intended” metabolic state, conserving critical fatty acids like DHA.
If a North Korean mother had previously eaten a diet that matched her genetic needs, and her child, once born, continued to eat that way, the developmental outcomes would likely be far more favourable than for a child born to a Black American mother consuming a poor, pro-inflammatory diet before and during pregnancy, through breastfeeding, and into childhood.
Because, even though a Black American mother may be well-nourished by calorie count, being exposed to a gene-diet mismatch is very likely to result in the depletion of DHA and critical micronutrients. And unlike the North Korean case, she may never have had a diet that matched her genetic needs, either before pregnancy or afterward, and nor does her child receive that postnatally. This makes it less likely that the mother or child ever experience the metabolic conditions necessary for optimal brain development.
What’s important is not food quantity, but food quality and how it interacts with ancestral metabolism.
Final Thought:
The gene–diet mismatch hypothesis has incredibly strong explanatory power and adeptly explains a modifiable bottleneck in cognitive development.
It says: many Black children may have the same genetic potential as their White, Jewish or East Asian peers, but are born into hostile biochemical conditions due to food systems mismatched with their metabolic design.
We don’t need to change people’s genes for a more equitable future. We can instead start by changing the food environment so that everyone has a chance to thrive. Learn more at InflammaFree.com.