A recent study looking at the effects of several types of oleaginous fruits on the brain found that these foods improve vascular and cognitive function in the brain.

So far, studies have proven countless times that walnuts have a protective effect against cognitive impairment. Even those who looked at a Mediterranean diet, which also includes nuts, showed cognitive benefits in older adults. In addition, randomized controlled trials (RCTs) have shown that walnuts have a positive effect on vascular function.

In a recent study published in the journal Clinical Nutrition, researchers evaluated the long-term effects of consuming a mixture of oleaginous fruits on cerebrovascular function in people over 60 years of age. Eligible participants were 28 healthy postmenopausal men and women aged 60 to 70 years with a stable body weight and a body mass index (BMI) of 25 kg/m2 to 35 kg/m2 (ie, overweight and obese).

Body mass index (BMI) measures weight in relation to height and is a screening tool that can determine a person’s weight group:

• overweight – BMI with values ​​in the range of 25 – 29.99;

• degree of obesity – BMI with values ​​from 30 to 34.99;

• obesity of the 2nd degree – BMI with values ​​in the range of 35 – 39.99;

• pathological obesity – BMI with values ​​over 40.

Subjects were excluded if they had nut intolerance or allergy, conditions that affected the results of the study, or contraindications to magnetic resonance imaging (MRI).

Participants consumed 60 grams of the oilseed mixture daily

The study included intervention and control periods of 16 weeks each. During the intervention periods, participants consumed 60 grams of a nut mixture each day that contained cashews, walnuts, hazelnuts, and pistachios. At the same time, they were instructed not to consume foods rich in omega-3 polyunsaturated fatty acids (PUFAs).

Peripheral and cerebral vascular function and cognitive performance were assessed at the end of each intervention and control period. Cerebral blood flow (CBC) was quantified using magnetic resonance imaging (MRI).

Cognitive performance was tested using the Cambridge Automated Testing Battery (CANTAB), a computerized neuropsychological test that provides a good assessment of cognitive function by analyzing visual perception, short-term and long-term memory, executive functions, and cognitive/psychomotor reaction speed.

In addition, the effect of oilseed consumption on arterial stiffness was investigated.

Bad fats decreased and good fats increased

The intervention periods during which the oilseed mixtures were consumed were well tolerated, and no protocol deviations or serious adverse events were reported. In addition, the consumption of oleaginous fruits led to a decrease in cholesterol and carbohydrate intake and an increase in fiber intake compared to control periods.

Eating nuts improved blood circulation in the brain

The study also found that there were no significant differences between the intervention and control periods in the whole brain, cortical and subcortical regions, or gray matter. However, a more detailed analysis indicated significantly higher regional cerebral blood flow (CBF) after the intervention periods during which oilseeds were consumed.

Cerebral blood flow (CBC) refers to the volume of blood passing through brain tissue over a certain period of time.

Cerebral blood flow delivers necessary substances (oxygen and glucose) to the brain and removes unnecessary ones (metabolic products). Any abnormality can lead to temporary brain dysfunction and lead to irreversible diseases such as Alzheimer’s disease.

The results of the study showed that cerebral blood flow increased during the intervention periods. This increase in cerebral blood flow results in improved visual and spatial memory and a 16% increase in the number of correct words.

The researchers note that there were no differences between the intervention and control periods on psychomotor speed, executive function, stress, quality of life, sleep quality, and mood.

Consumption of brain, intestinal flora and nuts

Several studies have shown over time that a diet rich in nuts can improve brain function, fight depression, and support brain function as we age.

Eating nuts can also help with gut health, mainly because of their high fiber content. A study involving 194 healthy adults who consumed approximately 40 g of walnut kernels per day for 8 weeks showed an increase in beneficial bacteria in the gut compared to when they did not consume them.

Nuts, what problems they can cause

The problems that the use of nuts can cause are related to their very high calorie content, 650 kcal per 100 grams. American experts in this field indicate a maximum daily intake of somewhere under 50 g. Basically, a few nuts per day, depending on the size, divided between meals.

The biggest problem with nuts is related to their potential allergenicity. Another effect is the presence of phytic acid, which prevents the absorption of some minerals in the blood. Hence, again, the need for moderate consumption.

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