Blood plasma instead of food questionnaires
The team of researchers combined innovations in neuroscience and nutritional science to set up a novel study to identify a nutrient profile that allowed people to perform well cognitively in older age. They enrolled 100 participants ages 65 to 75 years old to collect the usual data on their physical activity and body measurements. But instead of simply giving them a food questionnaire, they collected their blood plasma after a fasting period to analyse the nutrient biomarkers actually present in their blood. This removes a lot of the inaccuracies typically associated with food questionnaires. Participants also went through cognitive assessments and MRI scans.
“The unique aspect of our study lies in its comprehensive approach, integrating data on nutrition, cognitive function, and brain imaging. We simultaneously examine brain structure, function, and metabolism, demonstrating a direct link between these brain properties and cognitive abilities. Furthermore, we show that these brain properties are directly linked to diet and nutrition, as revealed by the patterns observed in nutrient biomarkers,” said Aron Keith Barbey, Professor of Psychology at the University of Nebraska.
The delayed brain ageing nutrient profile
These procedures helped researchers divide the participants into two groups, those with accelerated brain ageing and those with delayed brain ageing. Interestingly, those with delayed brain ageing had a distinct nutrient profile in their blood plasma. This profile showed increased concentrations of the following three nutrient groups.
- Fatty acids
- Carotenoids
- Vitamins
Looking at the group of fatty acids, the researchers found several specific ones to be increased. Some of these are well-known and expected to make an appearance. For example, these two omega-3 fatty acids, alpha-linolenic (ALA) and eicosapentaenoic (EPA), have already been linked to healthy brain function and appeared increased in this study too. Excellent dietary sources of EPA and ALA include fish and shellfish, flaxseed, hemp seed, olive oil, soy oil, canola oil, chia seeds, pumpkin seeds, sunflower seeds, leafy vegetables, and walnuts.
Mono-unsaturated fats are also generally considered healthy and two that were increased in people with delayed brain ageing were the vaccenic acid and gondoic acid. These fatty acids are found in olive oil and in dairy products such as milk, butter, and yoghurt.
Perhaps surprisingly, one saturated fatty acid also made the list. Saturated fatty acids are typically viewed as unhealthy. However, those with long carbon chains have been showing up as beneficial in some studies. This study saw an increase in lignoceric acids. Peanuts, macadamia nuts, and seed oils are good sources of this fatty acid.
The carotenoid group includes cis-lutein, trans-lutein and zeaxanthin, which are all powerful antioxidants. The researchers highlighted the following carotenoid-rich foods: spinach, kale, corn, bell peppers, tomatoes, watermelon, grapefruit, cantaloupe, broccoli, and carrots.
The vitamin group included two specific ones. Vitamin E was one of them and that’s no surprise as it’s often connected with better cognitive performance in other research. The researchers pointed to the following dietary sources of Vitamin E: nuts, seeds, vegetable oils, green leafy vegetables and fortified cereals. The second was choline, an essential B-vitamin-like nutrient. Excellent dietary sources of choline include animal-based proteins such as meat, poultry, fish, and eggs, as well as cruciferous vegetables and certain beans.
The Mediterranean diet offers the right nutrient profile
The nutrients described in this new study and the foods that carry them all point to the Mediterranean diet. The Mediterranean diet itself has been studied and shows protective effects for the brain, so it could serve as an easy way to give your brain all the nutrients it needs. If you want a refresher on this diet, check out our 5-day Mediterranean diet meal plan. The good news is that even the authors of the study seem to think that the Mediterranean diet is a good choice.
“We investigated specific nutrient biomarkers, such as fatty acid profiles, known in nutritional science to potentially offer health benefits. This aligns with the extensive body of research in the field demonstrating the positive health effects of the Mediterranean Diet, which emphasises foods rich in these beneficial nutrients,” said Prof Barbey.
