A new study published in JAMA Network Open is challenging some long-held assumptions about diet and brain health. Researchers from Sweden found that among older adults carrying the APOE4 gene—a genetic variant associated with a higher risk of Alzheimer’s disease—those who consumed more meat experienced slower cognitive decline and a lower risk of dementia than those who ate less meat. However, the type of meat mattered, and the findings do not suggest that everyone should suddenly start eating large amounts of processed meat.
Understanding APOE4 and Dementia Risk
The APOE gene helps regulate the transport and metabolism of fats and cholesterol in the body and brain. Everyone inherits two copies of this gene, one from each parent.
The APOE4 variant is the strongest common genetic risk factor for late-onset Alzheimer’s disease. Approximately 25–30% of people carry at least one APOE4 allele and having one or two copies significantly increases the risk of cognitive decline and dementia.
Researchers continue searching for dietary strategies that might help offset this genetic risk.
What Did the Study Find?
Researchers followed more than 2,100 adults aged 60 and older for up to 15 years. Participants completed dietary questionnaires and underwent regular cognitive testing.
Among individuals carrying the APOE3/4 or APOE4/4 genotype, those with the highest meat intake had:
- Slower rates of cognitive decline
- Better memory performance over time
- Approximately half the risk of developing dementia compared with APOE4 carriers who consumed the least meat
Perhaps most striking, APOE4 carriers who ate more meat performed similarly to people without the APOE4 risk gene. In other words, the cognitive disadvantage typically associated with APOE4 was largely absent among higher meat consumers.
Importantly, these benefits were not observed in participants without APOE4.
Not All Meat Was Equal
One of the most important findings was that processed meat appeared to have a different effect than unprocessed meat.
A higher proportion of processed meat—including bacon, sausage, hot dogs, deli meats, and cured meats—was associated with a higher risk of dementia regardless of APOE genotype.
The potentially protective association was seen with total meat intake, particularly when a larger percentage came from unprocessed sources such as:
- Beef
- Lamb
- Poultry
- Pork
- Other minimally processed meats
This finding reinforces a principle that has appeared repeatedly in nutrition research: food quality often matters more than simple food categories.
Why Might APOE4 Carriers Benefit?
The study was observational and cannot determine exactly why this relationship exists. However, researchers proposed several possible explanations.
Vitamin B12
Meat is one of the richest dietary sources of vitamin B12, a nutrient essential for:
- Memory
- Nerve function
- Methylation
- Healthy homocysteine metabolism
Vitamin B12 deficiency has been associated with cognitive impairment and accelerated brain aging. Some evidence suggests that APOE4 carriers may process or utilize nutrients differently, potentially increasing the importance of obtaining adequate B12.
Bioavailable Protein
Meat provides highly bioavailable essential amino acids that support:
- Neurotransmitter production
- Muscle mass maintenance
- Healthy aging
- Brain energy metabolism
- Liver detoxification
Maintaining muscle mass is increasingly recognized as an important factor in preserving cognitive function during aging. This why weight training is encouraged to improve brain health. Building strength with weight training is also important as we age to improve quality of life, prevent falls and be able to live independently well into our 8th decade and beyond
Choline: An Often Overlooked Brain Nutrient
Another nutrient that may help explain the study’s findings is choline, an essential nutrient found in animal foods such as beef, poultry, eggs, fish, and liver.
Choline serves several critical functions in the brain. It is a building block for acetylcholine, one of the most important neurotransmitters involved in memory, learning, attention, and cognitive processing. Acetylcholine-producing neurons are among the first to be affected in Alzheimer’s disease, which is why many Alzheimer’s medications are designed to increase acetylcholine activity in the brain.
Choline is also required for the production of phosphatidylcholine, a major component of cell membranes. Healthy cell membranes are essential for communication between brain cells, maintenance of neuronal structure, and overall brain function.
In addition, choline supports methylation, a biochemical process involved in DNA repair, neurotransmitter production, detoxification, and regulation of homocysteine levels. Elevated homocysteine has been associated with an increased risk of cognitive decline, Alzheimer’s disease, and vascular dementia.
Research suggests that many adults fail to meet recommended choline intakes, particularly those following diets that severely restrict animal foods. While some choline can be synthesized in the liver, endogenous production is generally insufficient to meet the body’s needs.
This may be particularly relevant for APOE4 carriers. Emerging evidence suggests that individuals with the APOE4 genotype may have altered phospholipid metabolism and greater vulnerability to age-related changes in brain cell membrane integrity. Some researchers have proposed that adequate dietary choline may be especially important for supporting brain structure and cognitive resilience in this population, although more research is needed.
Among commonly consumed foods, some of the richest sources of choline include:
- Beef liver
- Egg yolks
- Salmon
- Shrimp
- Beef
- Chicken and turkey
- Pork
While the JAMA Network Open study did not specifically measure choline intake, higher consumption of nutrient-dense, unprocessed animal foods would likely have increased choline intake, making it one plausible contributor to the improved cognitive outcomes observed among APOE4 carriers.
Creatine and Other Brain Nutrients
Animal foods also provide nutrients that are either absent or present in smaller amounts in plant foods, including:
- Creatine
- Carnitine
- Carnosine
- Taurine
- Heme iron
- Zinc
Many of these compounds play important roles in mitochondrial function, energy production, and neurological health. Lately, creatine supplementation has been explored for its role in supporting brain function. Food sources of creatine include animal proteins like red meat, poultry, pork and fish.
Evolutionary Considerations
The researchers also noted that APOE4 is considered the oldest form of the APOE gene based on human evolution. They hypothesized that individuals carrying APOE4 may have adapted to dietary patterns that included greater reliance on animal foods during human evolution. This remains speculative but provides an interesting area for future research.
What This Study Does NOT Mean
Before replacing your vegetables with steak, it’s important to understand the limitations.
This was an observational study. Researchers observed associations but could not prove that meat directly caused better cognitive outcomes.
Other factors or variables that could contribute to the findings include:
- Overall dietary patterns
- Physical activity
- Health status
- Socioeconomic factors
- History of toxic exposures
- Differences in nutrient intake beyond meat consumption
In addition, the study population consisted primarily of older adults from Sweden, so we must keep in mind that these findings may not apply equally to all populations.
Practical Takeaways
For individuals who know they carry APOE4, this study suggests that avoiding all meat may not necessarily be the most brain-supportive strategy. Knowing if you are a carrier of the ApoE4 gene can empower you to make the lifestyle changes that support brain function based on metabolic differences that increase the risk of developing Alzheimer’s disease.
- Limit processed meats
Choose primarily unprocessed sources of meat and poultry. Regular consumption of processed meats was associated with worse cognitive outcomes. I have many clients that rely on processed meats daily as a quick and easy protein source. Slices of turkey breast from the deli can offer convenience but unprocessed protein sources appear to have less potential for harm.
- Build a nutrient-dense dietary pattern by combining high-quality meats with plants
Pairing quality meats with 2-3 cups of plant foods provides fiber for the gut microbiome, nutrients for metabolic functions and phytochemicals needed for health maintenance.
Meat should be viewed as one component of a brain-healthy diet that also includes:
- Non-starchy vegetables
- Fruits
- Legumes
- Nuts and seeds
- Healthy fats from olive oil, avocado oil, nuts and seeds
- Seafood
- Adequate protein to meet one’s needs in their stage of life
- Monitoring Key Nutrients for Brain Health
Whether eating omnivorous, vegetarian, or plant-predominant diets, nutrients such as vitamin B12, iron, zinc, choline, DHA/EPA, vitamin D, magnesium and creatine deserve attention for long-term brain health. Any type of diet may put someone at risk for insufficient nutrient intake. This depends on the foods eaten as well as the influence of genetics and gut health.
Research Continues to Grow
This study adds to growing evidence that personalized nutrition plays an important role in healthy aging. For people carrying the APOE4 gene, higher consumption of unprocessed meat was associated with slower cognitive decline and lower dementia risk over 15 years of follow-up. Meanwhile, processed meats remained associated with poorer outcomes.
While more research is needed, the findings suggest that genetic differences may influence how individuals respond to different dietary patterns. The future of nutrition may be less about finding one diet that works for everyone and more about identifying the foods that work best for each person.
Precision medical nutrition therapy based on a person’s individual needs and lifestyle is the best approach when it comes to managing brain health. At Rezilir Health, we strive to stay abreast of the latest research and help patients apply it to their healing protocols. Genetic, cognitive, and nutrient testing, along with medical history and lifestyle, are all taken into account when people come to Rezilir Health for treatment. This allows us to tailor personalized recommendations to help you reach your health goals based on the latest research findings.
References below.
Keto Mongolian Beef
Ingredients:
- 1 Tablespoon avocado oil
- 2 teaspoons Minced ginger
- 1 Tablespoon Minced garlic
- ½ Cup Soy sauce or Coconut aminos
- ½ cup Water
- ¾ cup sugar free granulated sweetener such as allulose or monk fruit
- 1 ½ pounds Flank steak or Flatiron steak
- ¼ teaspoon Red pepper flakes
- 5 Stems Green onions-cut diagonal into 2 inch pieces
- Add broccoli florets, mushrooms, sliced carrots to increase fiber and
- medicinal plant compounds
- ¼ teaspoon xanthan gum (thickens sauce)
Instructions
Making the sauce:
- Heat 1 tablespoon Avocado Oil in a medium saucepan over medium heat.
- Add ginger, garlic, red pepper flakes and stir for 30 seconds.
- Add soy sauce, water and sweetener. Bring to a boil and simmer until thickened. Should take about 5 minutes.
- Remove from skillet to a bowl and set aside.
For the Steak:
- Slice steak against the grain into ¼ inch slices with the knife held at a 45-degree angle. I cut some of the longer pieces in half to make them bite-sized.
- Heat avocado oil in your skillet over medium-high heat.
- Add beef (may need to be cooked in 2 batches) and cook 2-3 minutes, until brown, flipping pieces over to cook both sides.
- Add the sauce to the pan along with the xanthan gum and cook over medium heat for a few minutes, stirring to coat the meat.
- Add green onions and remove the skillet from heat.
- Serve over cauliflower rice (available in frozen section or can be made by placing cut cauliflower florets in food processor until ground and then sautéing in a lightly oiled pan until cooked)
References:
Tardy AL, Pouteau E, Marquez D, Yilmaz C, Scholey A. Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence. Nutrients. 2020 Jan 16;12(1):228. doi: 10.3390/nu12010228. PMID: 31963141; PMCID: PMC7019700.
Roschel H, Gualano B, Ostojic SM, Rawson ES. Creatine Supplementation and Brain Health. Nutrients. 2021 Feb 10;13(2):586. doi: 10.3390/nu13020586. PMID: 33578876; PMCID: PMC7916590.
Norgren J, Carballo-Casla A, Grande G, Börjesson-Hanson A, Xu H, Eriksdotter M, Laukka EJ, Garcia-Ptacek S. Meat Consumption and Cognitive Health by APOE Genotype. JAMA Netw Open. 2026 Mar 2;9(3):e266489. doi: 10.1001/jamanetworkopen.2026.6489. PMID: 41854609; PMCID: PMC13003371.
