Researchers studied nearly 3,000 Americans over age 60 to see how different eating patterns affected their memory and thinking skills. They found that people who ate a lot of processed foods—even fortified ones with added nutrients—had weaker memory and thinking abilities compared to those eating more whole, natural foods. The connection was especially strong for people with high blood pressure or diabetes. This suggests that the way we choose our foods matters for keeping our brains sharp as we age, and that whole foods might be better for brain health than processed alternatives.

The Quick Take

  • What they studied: Whether different eating patterns—especially diets heavy in processed foods—affect memory and thinking abilities in older people
  • Who participated: 2,991 Americans aged 60 and older who participated in a national health survey between 2011 and 2014
  • Key finding: People eating a diet high in processed foods (even fortified ones) scored lower on memory tests by about 0.43 points compared to others, and this difference remained even after accounting for other health factors
  • What it means for you: Choosing whole, minimally processed foods over processed alternatives may help protect your memory and thinking skills as you age, especially if you have high blood pressure or diabetes. However, this is one study and more research is needed before making major dietary changes.

The Research Details

Scientists analyzed information from a large national health survey called NHANES that tracked what Americans ate and tested their brain function. They looked at detailed food diaries from participants and used a special statistical method called latent class analysis to identify four different eating patterns based on nutrient density—essentially how many nutrients people got from their food choices.

Participants took three different brain tests: one for memory (remembering words), one for quick thinking (naming animals quickly), and one for processing speed (matching symbols to numbers). The researchers then compared how well people with different eating patterns performed on these tests.

The team carefully adjusted their results to account for other things that affect brain health, like age, education, exercise, sleep, and existing health conditions like heart disease or diabetes.

This approach is important because it looks at real eating patterns rather than single nutrients in isolation. People don’t eat individual vitamins—they eat meals made up of many foods. By studying actual eating patterns, researchers can better understand how our real-world food choices affect brain health.

This study used a large, representative sample of older Americans, which makes the findings more likely to apply to the general population. The researchers carefully measured diet through detailed food recalls and used standardized brain tests. However, because this is observational research (watching what people eat rather than randomly assigning them to diets), we can’t be completely certain that processed foods directly cause worse brain function—other factors could be involved.

What the Results Show

The researchers identified four distinct eating patterns among the participants. The pattern most associated with worse brain health was labeled ‘High-Nutrient, Ultra-Processed’—meaning people ate a lot of processed foods that had nutrients added to them, but consumed fewer plant-based whole foods like vegetables, fruits, and whole grains.

People following this ultra-processed pattern scored significantly lower on memory tests, with a difference of about 0.43 points on the test scale. This association remained strong even after the researchers accounted for age, education, physical activity, sleep quality, and other health conditions.

Interestingly, the connection between processed foods and poor brain performance was even stronger in people who had high blood pressure or diabetes. This suggests that people with these conditions may be especially vulnerable to the brain effects of processed food diets.

The other three eating patterns identified (which included more whole foods and plant-based nutrients) were not associated with the same level of cognitive decline.

While memory showed the clearest connection to diet patterns, the researchers also measured thinking speed and quick verbal abilities. The ultra-processed pattern showed weaker associations with these other brain functions, suggesting that memory may be particularly sensitive to diet quality. The findings were consistent across different age groups and education levels, though the effects were most pronounced in people with existing cardiometabolic conditions.

Previous research has suggested that Mediterranean-style diets and diets rich in whole foods support brain health, while diets high in processed foods and added sugars may increase dementia risk. This study adds to that evidence by showing that even when processed foods are fortified with added nutrients, they don’t provide the same brain-protective benefits as whole, minimally processed foods. The finding that people with diabetes and high blood pressure are more vulnerable aligns with other research showing these conditions increase dementia risk.

Because this study observed what people naturally ate rather than randomly assigning them to different diets, we cannot definitively say that processed foods cause worse brain function—other lifestyle factors could explain the connection. The study captured diet at one point in time, so we don’t know if long-term eating patterns have stronger effects. Additionally, the cognitive tests used are brief screening tools rather than comprehensive brain evaluations, so subtle effects might be missed.

The Bottom Line

Based on this research, older adults—particularly those with high blood pressure or diabetes—should consider emphasizing whole, minimally processed foods in their diet, including vegetables, fruits, whole grains, nuts, and legumes. This recommendation has moderate confidence because it’s supported by this study plus other research, but it’s not yet definitive enough to be a strong clinical guideline. People should consult with their doctor or a registered dietitian before making significant dietary changes, especially if they take medications.

This research is most relevant for adults over 60, particularly those with high blood pressure, diabetes, or concerns about memory and thinking. It’s also important for family members and caregivers of older adults. People without these conditions may still benefit from eating more whole foods, but the evidence is strongest for the groups mentioned. This doesn’t apply to children or young adults, whose brain development follows different patterns.

Brain health changes from diet typically develop over months to years, not days or weeks. You might notice improvements in mental clarity or focus within a few weeks of changing your diet, but significant effects on memory and thinking speed could take several months to become apparent. Consistency matters more than perfection.

Want to Apply This Research?

  • Track the percentage of meals each day that contain primarily whole, minimally processed foods versus ultra-processed foods. Aim to increase whole-food meals from your current baseline by 10-20% each week, with a goal of 70-80% of meals being minimally processed.
  • Use the app to log meals and receive real-time feedback on nutrient density. Set a daily goal to include at least one vegetable, one fruit, and one whole grain with each meal. Create shopping lists focused on whole foods and use the app’s reminder feature to prompt healthier choices at meal times.
  • Weekly check-ins on the percentage of whole-food meals consumed. Monthly self-assessment of mental clarity, memory, and focus using simple rating scales (1-10). Quarterly review of overall eating pattern trends and adjustment of goals based on progress and any changes in health status.

This research suggests an association between processed food consumption and cognitive decline in older adults, but does not prove that processed foods directly cause memory problems. Individual results vary based on genetics, overall lifestyle, and health status. This information is for educational purposes and should not replace professional medical advice. Anyone concerned about memory loss or cognitive changes should consult with a healthcare provider for proper evaluation and personalized recommendations. People taking medications or with existing health conditions should discuss dietary changes with their doctor or a registered dietitian before making significant modifications to their diet.