Epicatechin-Enriched Cacao Subproducts Improve Cognition in Older Subjects: Proof of Concept

Abstract

Cognitive decline among older people is a growing concern worldwide since it impacts quality of life and independence. Recently, we reported that an epicatechin-enriched product improves cardiometabolic status, physical performance/mobility, and quality of life (QoL) in over-60-year-old subjects. Here, we explored the effects of an (−)-epicatechin-enriched cacao supplement on the cognitive conditions of older and sedentary individuals residing in a community center. Twelve persons with the inclusion criteria were included in this proof-of-concept study. We evaluated reasoning, memory, attention, coordination, and perception using CogniFit software, version 4.6.18. Patients received a mixture of cacao flour and 15 mg of free (−)-epicatechin twice daily for 3 months. The main results from the trial suggested a positive and significant improvement in perception, coordination, reasoning, attention, and memory.

1. Introduction

Cognitive decline among older people is a growing concern worldwide as populations age [1]. A parallel increase in the prevalence of age-related cognitive impairments appears with a longer lifespan. The decline in cognitive function can significantly impact quality of life and independence. Understanding the causes, manifestations, and potential interventions for cognitive decline in older adults is crucial for improving their well-being and promoting healthy aging. Numerous factors contribute to cognitive decline in older adults. As individuals age, changes occur in the brain’s structure and function, including reductions in the volume of specific brain regions and neurotransmitter levels, affecting cognitive abilities [2,3]. Unhealthy habits such as smoking, excessive alcohol consumption, poor diet, lack of physical activity, and inadequate sleep have been linked to cognitive impairment in older adults [4].

Cardiovascular risk factors like arterial hypertension, diabetes, hypercholesterolemia, and obesity can also increase the risk of cognitive decline by compromising blood flow to the brain and promoting the development of vascular disease [5]. In the same context, elderly-related pathological conditions such as Alzheimer’s disease, Parkinson’s disease, and vascular dementia are characterized by progressive deterioration of brain function, resulting in cognitive decline [6].

The manifestations of cognitive decline can vary widely among individuals but often include the following: (1) memory loss, difficulty remembering recent events, names, and information, which is a common early sign of cognitive decline that can progress over time; (2) impairment in executive function with difficulties with planning, decision-making, problem-solving, and multitasking; (3) language and communication problems with reduced vocabulary, difficulty finding the right words, and challenges in understanding and expressing ideas; (4) and decreased attention and concentration may be easily distracted [6,7].

Prevention and treatment of cognitive decline in older persons present significant challenges; specific treatment does not exist; however, some strategies and interventions can help manage symptoms and improve quality of life. Adopting a healthy lifestyle, including regular exercise, a balanced diet, adequate sleep, and stress management, can promote brain health and reduce the risk of cognitive decline. Engaging in mentally stimulating activities, maintaining social connections, participating in social activities, and learning new skills can help maintain cognitive function and slow decline. Proactive strategies to prevent cognitive dysfunction in the aging demographic should be prioritized.

In the recent past, we and others have demonstrated that flavonoid-rich food interventions, particularly with (-)-epicatechin (EC), can attenuate biomarkers of inflammation and improve cardiovascular risk markers and mobility in aged subjects [8].

Flavonoids are ubiquitous plant secondary metabolites with a 15-carbon structure (two phenyl rings and a heterocyclic ring; C6-C3-C6). Dietary flavonoids are found in cacao, tea, berry fruit, citrus, and other fruits and legumes. The potential for flavonoids to attenuate neurodegeneration was recognized [9], and growing epidemiological, in vivo, and clinical evidence suggests that supplementation with flavonoid-rich foods benefits cognitive function [10,11,12]. The underlying mechanisms may include flavonoids’ anti-inflammatory capacity, antioxidant activity, together with positive effects on endogenous modulators of free radicals [8,9,11] and influence on endothelial function and peripheral blood flow [12,13,14].

Dietary flavonoid consumption promotes peripheral and cerebral vascular flow, neuronal survival, and improves mobility, and it is associated with a decreased risk of age-associated sarcopenia [8,9,10].

Recently, we reported that an epicatechin-enriched product improves cardiometabolic status, physical performance/mobility, and quality of life (QoL) in subjects over 60 years old [8], with the reduction in oxidative stress and inflammation markers, facilitating an active engagement of individuals in physical activities, leading to increased mobility.

Based on those results, we decided to explore the effects of three months of treatment with an epicatechin-enriched product on the cognitive conditions of a group of older subjects living in a community center in a proof-of-concept preliminary study.

2. Materials and Methods

2.1. Subjects

Participants were recruited through convenience sampling in a community center in Mexico City; all were recruited in the same one-month period. Since this was an open-label proof-of-concept study, the evaluations (initial vs. final) were performed under the supervision of two researchers. A third researcher performed the analysis and report.

2.2. Inclusion Criteria

The inclusion criteria were hand strength (women < 20 kg, men < 30 kg), up and go test (>10 s), and skeletal muscle index (women < 6.42 kg/m², men < 8.87 kg/m²) [8].

2.2.1. Handgrip Strength

Strength was measured using a digital handgrip dynamometer on the dominant hand, averaging the values recorded from three consecutive maximal effort grips. The highest value measured was considered the patient’s representative handgrip strength.

2.2.2. Up and Go Test [8]

Subjects were seated back in an armchair. On the word “go”, they got up, walked through a 3 m line on the floor, turned around, walked back to the chair, and sat down. Time was recorded using a stopwatch [8].

2.2.3. Skeletal Muscle Index (SMI)

Based on the definition of the European Working Group on Sarcopenia in Older People, we calculated the skeletal muscle index (SMI) by dividing the estimated muscle mass (kg) by the square of the height (m²). SMI values < 8.87 kg/m² (men) and <6.42 kg/m² (women) were considered indicative of sarcopenia [8].

2.3. Non-Inclusion Criteria

Non-inclusion criteria were habitual consumption of antioxidant supplements, cocoa products, benzodiazepines, or protein supplements, and chronic incapacitation illnesses.

2.4. Study Design

Participants signed an informed consent indicating their willingness to participate in the study and allow for the use of the collected data for research purposes.

Each subject was its own control (initial values) since cognition evaluation was performed at the beginning and the end of the study.

Evaluations were performed using CogniFit software, a personalized program based on a short (10 min) assessment [15].

The program was used to screen cognitive function. It is a computer-assessed neuropsychological test battery that has been validated against standard neuropsychological tests [15]. CogniFit scores range from 0 to 800 points. Mental abilities are considered weak for scores between 0 and 200. Subjects with scores of 200–400 are considered to have cognitive skills that need improvement. Higher scores in the range of 400–600 suggest that cognitive abilities are in good condition. Scores above 600 are considered strong.

Scores on cognitive abilities are assigned using factor analyses performed on normative data and are standardized into Z-scores [15]. Specifically, we examined the following: (1) Reasoning (velocity, planification, and flexibility); (2) Memory (short-term, non-verbal memory, short-term visual, short-term phonological memory, contextual and working memory (ability to store and handle information to perform complex cognitive tasks temporarily)); (3) Attention (focalized and divided attention and monitorization); (4) Coordination (eye–hand and time–response); and (5) Perception (visual, auditive, and recognizing).

2.5. Treatment

This was a single-center, proof-of-concept study evaluating the effects of 3 months of treatment with a non-commercially available (−)-epicatechin-enriched cacao supplement prepared in a good manufacturing process (GMP) facility. Patients received a flask containing 60 capsules with 500 mg of a mixture of cacao flour and 15 mg of free (−)-epicatechin. Patients were instructed to ingest one pill twice daily before meals. They received a new flask every 30 days. Treatments were provided for three months. A total of 20 subjects were included (10 men and 10 women). This study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Institutional Ethics and Research Committees. All included subjects signed an informed consent.

2.6. Statistical Analysis

Data are reported as mean ± standard error of the mean (SEM) or percentages when appropriate. Students’ t-tests (paired, before, and after) were used to compare the means of the groups for continuous variables. The chi-square test was used for categorical variables. All cognitive variables were converted to z-scores by subtracting the score from the total sample mean at the first assessment and dividing the difference by the standard deviation (SD). Statistical significance was considered when the p-value was less than 0.05. Analyses were performed with GraphPad Prism, v10.0.

3. Results

Twenty-four subjects were invited to participate. A total of 20 subjects (10 men and 10 women) who fulfilled the inclusion criteria and agreed to sign the informed consent form were included in the study.

Table 1. Basal data of participants.

	Mean ± SEM	Men	Women
Age (years)	67.75 ± 1.927	67 ± 2.07	68.5 ± 3.44
Body weight (kg)	69.85 ± 11.5	68.3 ± 11.2	71.4 ± 11.4
Initial values; n (%)
Low hand strength	12 (100)	6 (100) <30 kg	6 (100) <20 kg
Low up and go test >10 s	12 (100)	6 (100)	6 (100)
Skeletal muscle index	12 (100)	6 (100) <8.87 kg/m2	6 (100) <6.42 kg/m2

shows the initial data.

The analysis of the global cognition status shows that at the beginning of the trial, the subjects had an average of 252.7 ± 37.28 points, indicating a value that needs to improve. Three months of treatment with the epicatechin-enriched supplement significantly increased the average to 303.4 ± 34.9 points (p = 0.0322) (Figure 1).

The analysis of reasoning capabilities shows an initial mean of 338.5 ± 62.3 and a statistically significant improvement to 414.6 ± 48.9 (p < 0.01), reaching levels of good condition (Figure 2A).

The analysis of reasoning variables showed that reasoning velocity changed significantly from 344.9 ± 75.75 to 501.8 ± 76.78 (p = 0.048) (Figure 2B). Reasoning planning had a significant (p = 0.037) increase from 187 ± 45.98 to 302.9 ± 63.95 (Figure 2C). Reasoning flexibility also had a significant (p = 0.032) increase from 515.7 ± 89.75 to 646.8 ± 61.42 (Figure 2D).

The analysis of memory shows a positive and significant change from 153.4 ± 31.15 (considered as a value suggesting a weak memory) to a value of 244.4 ± 41.38, still needing attention but suggesting an improvement (Figure 3).

The analysis of memory variables suggested a positive and significant change in short-term memory from 179.2 ± 58.62 (week) to 325 ± 72.9 (p = 0.036) (Figure 4A).

Also, a positive and significant change in nonverbal memory was found from 130.0 ± 25.44 to 190.9 ± 40.15 (Figure 4B). Figure 4C shows the change in working memory from 183.2 ± 37.7 to 265.8 ± 44.29 (p = 0.03). Finally, a significant change in contextual memory was found, from 230.1 ± 59.37 to 302.4 ± 58.17 (p = 0.006) (Figure 4D). We found no significant changes in short-term auditory, short-term visual, and denominatory memories.

The attention analysis suggested a positive change in the analyzed subjects, passing from 335.4 ± 47.18 to 446.3 ± 47.75 (p = 0.012), Figure 5A.

Figure 5 shows the analysis of focused, divided, and monitoring attention. Focused attention showed no differences (Figure 5B). A positive change was found in divided attention. The initial value of 564.3 ± 77.14 increased to 668.9 ± 49.68 (p = 0.007) (Figure 5C), and monitoring increased from 273.9 ± 71.98 to 423.7 ± 56.07 (p = 0.02) (Figure 5D).

The analysis of coordination also provides positive results. Coordination (Figure 6A) changed from 133.8 ± 32.81 to 148.8 ± 31.61 (p = 0.025), and eye–hand coordination with an initial value of 59.17 ± 19.83 goes to 114.2 ± 24.17 (p = 0.0058) (Figure 6B). However, time–response coordination shows no change after treatment (Figure 6C).

On the other hand, perception changed from 294.7 ± 38.62 to 334.2 ± 41.19 (p = 0.046) (Figure 7A), visual perception changed from 338.2 ± 67.58 to 442.8 ± 73.13 (p = 0.020) (Figure 7B), and auditive perception changed from 203.3 ± 49.57 to 283.4 ± 53.98 (p = 0.004) (Figure 7C). Spatial perception, visual scanning, recognition, and estimation did not change significantly.

To gain a deeper understanding of the changes’ relevance, we used a Z-score analysis to compare the changes induced by the treatment with the initial values. A Z-score is a statistical value describing a value’s relationship to the mean of a group of values. It is measured in terms of standard deviations from the mean. If a Z-score is 0, the data point’s score is identical to the mean score. A Z-score of 1.0 would indicate a value of one standard deviation from the mean. The analysis of the z-scores for each case is presented in

Table 2. Z-scores of variables were analyzed using Cognifit software after three months of treatment with an epicatechin-enriched supplement. (A) Changes in main categories; (B) changes in subcategories.

	Z-Score (A)	Z-Score (B)
Global status	0.4195
Reasoning	0.4497
Processing velocity		2.0435
Reasoning planning		1.8124
Cognitive flexibility		2.1345
Memory	0.6350
Short-term memory		2.0000
Non-verbal memory		1.4944
Working memory		1.8650
Contextual memory		1.2429
Attention	2.3225
Focused attention		0.8283
Divided attention		2.1055
Attention monitoring		2.8322
Coordination	0.4745
Eye–hand coordination		2.2768
Time–response coordination		0.0651
Perception	0.9589
Visual perception		1.4303
Auditory perception		1.4839

; the values suggest a positive and significant change induced by the ingestion of an epicatechin-enriched supplement made with cacao by-products.

The results suggested a substantial improvement in cognitive functions with the epicatechin-enriched supplement.

4. Discussion

The main results from this proof-of-concept trial on cognition, using an epicatechin-enriched supplement elaborated from cacao sub-products during three months in a group of sedentary subjects older than 65 years with low hand strength, up and go test, and skeletal muscle index, indicators of sarcopenia, suggested a positive and significant improvement. The initial evaluation of cognitive function, perception, coordination, reasoning, attention, and memory revealed values associated with cognitive weakness or low levels in the intermediate category, as expected, with a significant decrease in cognitive capabilities.

Three months of treatment with an epicatechin-enriched supplement elaborated with cacao by-products showed a remarkable improvement, reaching good condition levels in some of the analyzed variables.

The age-related decline may commonly include overall slowness in thinking and difficulties sustaining attention, multitasking, retaining information in mind, and word-finding [16]. However, the decline in cognition is not uniform in normal aging since reading and verbal reasoning do not always decrease [1].

Abnormal aging, mainly associated with sedentarism or low levels of mobility, leads to more severe cognitive declines. Abnormal aging can also include the motor system, resulting in excessive tripping, falls, or tremors [16].

There are several risk factors associated with cognitive decline: type 2 diabetes, high blood pressure, obesity, smoking, depression, little or no mental activity, little or no physical exercise, etc. The group explored in this trial has a high risk of developing this pathology.

Among modifiable risk factors, dietary factors have been identified as having a potential role in preserving and possibly improving mental health and cognitive function in older adults [17]. Recently, we showed that cacao by-products can reduce cardiovascular risk in overweight patients, suggesting potential use of these by-products, which are essentially calorie-free and rich in flavanols, to facilitate the achievement of preventive goals [18]. We also demonstrate, in a group of (55–70 y.o.) subjects using similar products to those used in the present work, that flavanol consumption positively affects blood oxidative stress and inflammation, cardiometabolic risk markers, physical performance, and quality of life [8]. Based on the previous results, we aimed to explore whether those positive effects also reflect improved cognitive capacities. First, we include six women and six men in this proof-of-concept study. Even when we found significant changes in the cognitive characteristics evaluated, we did not find differences between the sexes.

Cognitive interventions have proven effective for maintaining and improving cognitive functioning in older adults regardless of their initial cognitive status [19,20].

If possible, improving metabolism and mobility (adequate diet and exercise) are the most effective approaches to decreasing cognitive decline in older adults. However, this is only sometimes possible because they may have multiple illnesses and comorbidities that impede mobility and good nutrition.

We have demonstrated that epicatechin, a flavanol widely distributed in nature but particularly abundant in the cacao pod and seeds, induces vasodilation and can improve cellular bioenergetics by inducing mitochondrial biogenesis (i.e., adipose tissue, skeletal muscle, and brain), improving the metabolism and, in consequence, increasing mobility in aging mice [21]. A similar phenomenon occurs in humans since epicatechin supplement consumption positively affects blood oxidative stress and inflammation, cardiometabolic risk markers, physical performance, and quality of life [8]. We hypothesized that cognition must be influenced positively by an epicatechin-enriched supplement elaborated with cacao by-products. Our results demonstrated this is the case; 3 months of treatment with this product improved cognitive behavior in this group of persons.

Our results agree with the proposal [22], suggesting that flavonoids and their metabolites activate signaling pathways to regulate synaptic plasticity, reduce neuroinflammation, and induce vascular effects involved in maintaining optimal neuronal function, limiting neurodegeneration, and preventing or reversing age-dependent cognitive deterioration.

Also, chronic studies observed significant benefits in older adults with low and medium doses. Long-term memory, processing speed, and mood domains showed sensitivity to flavonoid intervention [23].

The results reported in this work have several limitations: the number of subjects included is low, and it was not compared against a placebo and randomly assigned; however, even when it is a proof of concept using a supplement elaborated with cacao by-products and is low cost, low in calories, and essentially free of adverse effects, the results strongly support an improvement if global cognitive status, including positive changes in reasoning, memory, attention, perception, and coordination, signals better possibilities for these persons as well as achieving a decrease in inflammation and cardiometabolic risk markers and increase in physical performance, resulting in a better quality of life [8] with better outcomes in independence, decreasing familial and society economic burden.

However, more work is necessary to implement this type of maneuver early in life, altogether with controlling cardiometabolic risks to decrease the possibility of decline and improve society’s wellness in older persons.

5. Conclusions

The results presented in this work showed that treatment with an epicatechin-enriched supplement, a low-cost and natural product, improved cognitive function in subjects older than 65 years, opening several possibilities to improve the quality of life in the elderly.