Brain Fog and Cognitive Impairment: Support from Nature with Standardized Extracts
A New Cognitive Deficit?
“Mens sana in corpore sano,” as the Romans said as early as the 1st century A.D.; however, the latest epidemiological studies suggest that this is becoming less and less true, even though taking care of one’s body and health has now become an established habit. On the other hand, while mental sharpness has long been perceived as a privilege of youth and its gradual decline as an inevitable consequence of aging, the most recent data reveal a very different, more concerning reality.
A recent nationwide study conducted in the U.S. found that the overall prevalence of self-reported cognitive disability rose from 5.3% in 2013 to 7.4% in 2023. The most pronounced increase was among adults under 40, whose rates nearly doubled—from 5.1% to 9.7% over the course of a decade. Paradoxically, a slight decline was observed among those over 70 during the same period. It is therefore no longer a deficit that depends only on physiological aging.
Regarding gender, no significant differences were reported, but the slight prevalence among women observed at the beginning of the study (2013) had reversed by the end of the observed period (2023).
The occurrence gained media attention during the COVID-19 pandemic: a meta-analysis of over 25,000 patients estimated a 30% prevalence of brain fog among long-COVID patients, with women showing significantly higher rates than men (34% vs. 23%).
However, when it comes to environmental and lifestyle factors, certain recurring factors stand out: chronic stress, sleep deprivation, poor nutrition, a sedentary lifestyle, and excessive digital stimulation.
A Millennia-Old Struggle: The Pursuit of Mental Clarity as Holistic Well-Being
Juvenal’s famous phrase, found in the “Satire” (X, 356), remains to this day a lucid summary of the ideal of holistic well-being. But other traditions have also sought to achieve a balance between physical and mental well-being. In Ayurvedic medicine, remedies classified as medhya rasayana—literally “those that nourish the intellect and rejuvenate”—occupy a chapter of their own in the Ashtanga Hridayam, the 6th-century CE treatise written by the physician Vagbhata. In traditional Chinese medicine, “qi tonics” for the mind were reserved for scholars and imperial officials: mental clarity was a precious state resource.
Brain Fog and Cognitive Decline: Two Distinct Conditions
Today, the age-old pursuit of physical well-being and cognitive clarity seems to be under threat from an increasingly stressful lifestyle.
It is important to distinguish between two conditions that are often confused in everyday language.
Brain fog—literally “brain fog”—is not a clinical diagnosis, but rather a group of subjective symptoms such as difficulty concentrating, impaired short-term memory, mental fatigue, and trouble finding the right words or making decisions. It is a widespread, often underestimated condition that is strongly linked to chronic stress, sleep disorders, hormonal imbalance, inflammation, and oxidative stress.
Mild cognitive impairment (MCI), on the other hand, is a clinically recognized and measurable stage that lies between normal cognitive aging and brain impairment (dementia). Common symptoms are a decline in one or more cognitive areas—memory, attention, executive functions, processing speed—that exceeds what is expected for the relevant age group, without, however, significantly impairing daily activities. It can be reversible and does not necessarily progress to dementia.
However, the two conditions are not clearly distinct: chronic, unmanaged “brain fog” can progress to more severe forms of cognitive impairment. And it is precisely during this subclinical phase that botanical support can prove beneficial.
The Role of the HPA Axis: Why Chronic Stress Can Impair Cognitive Function
To understand why adaptogenic plants and other botanicals that act on the hypothalamic-pituitary-adrenal (HPA) axis are used to support cognitive function, it is necessary to understand the physiological mechanism of stress.
The hypothalamic-pituitary-adrenal (HPA) axis is the body’s primary stress response system. When faced with a stressor, the hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to produce ACTH (adrenocorticotropic hormone), which in turn causes the adrenal cortex to release cortisol, the so-called stress hormone. This is a valuable adaptive mechanism in the short term: the activation of this cascade enables the “fight-or-flight” response. Cortisol boosts metabolism, providing the body with an excess of glucose while suppressing energy-consuming processes, such as the immune system.
If stress persists over time, excess cortisol can have harmful effects on various functions, such as the immune, endocrine, and cardiovascular systems, as well as the central nervous system.
Chronic excess cortisol negatively affects the hippocampus—the brain region essential for memory and learning—by reducing neurogenesis, damaging synapses, and impairing glutamatergic transmission. It can also cause sleep disturbances, such as difficulty falling asleep or frequent awakenings, which, in turn, negatively affect cognitive abilities.
Adaptogenic plants—which modulate the HPA axis response and reduce cortisol levels in chronic stress—can therefore have an effect that goes beyond simply reducing fatigue and directly impacts cognitive health. More generally, all plants that modulate cortisol release may be beneficial.
Which plants can help?
Panax ginseng — The Cure-all — and Other Adaptogenic Plants
Ginseng is probably the oldest recorded medicinal plant. Known for about 7,000 years, it is listed among the most valuable plants in the Shennong Bencao Jing, the Chinese pharmacopoeia dating back over two thousand years, where it was classified as a superior remedy (shang pin), suitable not for curing diseases but for improving vitality and prolonging life. While “ginseng” in Chinese means “plant of man” due to its anthropomorphic appearance, the term “Panax,”—which identifies the botanical genus of these plants belonging to the Araliaceae family—comes from ancient Greek and has a meaning similar to the Latin word “panacea,” that is, “all healing.”
For 3,000 years, a similar role has been attributed to Ashwagandha (Withania somnifera)—known, not coincidentally, as “Indian ginseng”, a “rasayana” remedy par excellence in Ayurveda—and to Maca (Lepidium meyenii), the “ginseng of the Andes,” cultivated in the Peruvian mountains since pre-Inca times as a food and tonic for physical and cognitive endurance.
The adaptogenic and cognitive effects of ginseng are primarily mediated by ginsenosides, tetracyclic triterpene saponins that, due to their chemical structure similar to that of corticosteroid hormones, exert a modulatory effect on the central nervous system through multiple mechanisms: regulation of neurotransmitters, reduction of neuronal oxidative stress, anti-inflammatory action, and modulation of the HPA axis. Ginsenosides in the Rb1 and Rg1 groups are the most extensively studied for their effects on memory and learning.
A 2024 systematic review and meta-analysis confirmed a positive effect of ginseng preparations on cognitive function, especially on memory improvement.
It is also important to highlight the enormous heterogeneity of ginseng-based products on the market and their variable quality. A very common form of adulteration, for example, lies in using the aerial parts instead of the root, since the former are less valuable than the underground organ and much cheaper. However, the leaves have a different ginsenoside content and composition than the roots, leading to different biological activity.
If you’d like to learn how our high-quality ginseng root extract differs from commercial products made partly or entirely from leaves, download our brochure.
The Anti-Stress Properties of Scutellaria lateriflora and Lavandula angustifolia
A lesser-known natural remedy is Scutellaria lateriflora (Blue Skullcap), a perennial herb native to North America that has traditionally been used to promote relaxation and sleep.
A study published in January 2024 helped lay the scientific ground for this use, demonstrating that a chemically characterized extract of Scutellaria lateriflora L. (BlueCALM®) exerts a significant inhibitory effect on cortisol release in an in vitro model.
In light of these results, BlueCalm® was tested as a nutraceutical ingredient in a recently published clinical study, whose primary objective was to evaluate the dietary supplement’s efficacy in maintaining a proper sleep-wake balance (sleep quality) and, as a secondary objective, its effect on sleep quality, through the filling of validated, internationally recognized questionnaires and a sleep diary. The results demonstrated a statistically significant improvement compared to baseline in all treated volunteers.
To learn more about BlueCALM®, our dry extract standardized to 10% baicalin, sourced from Italian supply chains (in Lombardy and Trentino) and identified via DNA barcoding to prevent adulteration by morphologically similar but hepatotoxic species of the genus Teucrium, download our brochure.
The dry extract of lavender produced by EPO, standardized to contain polyphenols and obtained exclusively from Lavandula angustifolia Mill., in an experimental model commonly used to investigate the mechanism of action of molecules with anxiolytic activity, significantly inhibited cortisol release, via the same mechanism of action previously demonstrated for Scutellaria lateriflora L. (BlueCALM®).
Standardization: Why Not All Extracts Are Equivalent
A common issue for all the plants discussed—and an often underestimated matter in commercial formulations—is the standardization of extracts. Plant-based raw materials are inherently variable: the content of active ingredients depends on geographic origin, harvest time, and, above all, the production method. This can affect the efficacy and safety of the extract.
EPO Srl, with over 90 years of experience in the production of plant extracts, guarantees the standardization of active ingredients in its extracts using official and validated analytical methods. For Branded Extracts, EPO also provides efficacy studies with a particular focus on bioaccessibility and bioavailability, which are key factors to translate in vitro activity into clinically relevant effects.
For information on EPO extracts, visit www.eposrl.com or contact the EPO sales team.