What are functional foods?
The functional food sector is increasingly the subject of interest and development. It does not enjoy a real categorization and in fact it is not well defined at the regulatory level; on the other hand, the scientific side arouses much curiosity and attention. The European Food Information Council (EUFIC) has defined a food as “functional” if it “proves to have satisfactorily positive effects on one or more specific functions of the organism that go beyond the normal nutritional effects, in such a way that it is relevant for the improvement of health and well-being and/or for the reduction of the risk of disease”. This definition was also taken up in the European Commission’s publication Functional Foods of 2010.
On the other hand, the European standard CE 1924/2006 serves to link nutritional and/or health claims of foods in terms of communication to consumers. In general terms, in fact, it has been recognised, that “foods promoted through indications can be perceived by the consumer as advantageous from the traditional point of view, compared to other similar products. This may encourage consumers to make choices that directly affect the intake of individual nutrients in a way that is different or contrary to what has been scientifically reported”.
Functional foods for the mind
Now, among functional foods there is a typology that is labeled “brain foods”, which identifies foods that, due to their composition, have a more direct effect on functions related to knowledge, memory and other cognitive functions. Those that contain one or more of the following nutritional principles are considered as such: iron, zinc, iodine, magnesium, vitamin B1, vitamin B3, vitamin B6, vitamin B12, folic acid and vitamin C. Health claims on these they express themselves as “contributes to normal cognitive function” or “contributes to the normal functioning of the nervous system”.
For omega-3 fatty acids such as DHA, on the other hand, the claim “contributes to the maintenance of normal brain function” is used provided that the food contains at least 40mg/100g of DHA. Then there are certain vegetable or herbal preparations that are labeled with the claim on brain function. Among these are those based on Gingko biloba (reference to cognitive functions), Erica cinerea (memory and cognitive functions) and oats (Avena sativa); the latter also enjoys a claim “against mental fatigue”.
Mental youth and lifestyle
The lifestyle we lead can affect the aforementioned neurogenesis and how new brain cells connect with each other and contribute to brain function. It all depends on our choices and nutrition can play a significant role in this, given that it is only in the last two decades that researchers have understood the connections between diet, obesity and neurogenesis in the adult brain. In particular, neurogenesis from the hippocampus is better with more controlled meals, with a greater interval time between them. More consistent foods lower the phenomenon, while prolonged chewing has the reverse effect. Meals containing sources of omega-3 and polyphenols of green tea or red wine have a favorable effect on neurogenesis, while saturated fats limit it due to the damaging effect on the blood-brain barrier and the production of inflammatory cytokines.
Even caloric restriction (fasting or fasting-like) has a positive effect on this biological phenomenon, being able to increase up to 30%. Exercise has been shown to promote neurogenesis. Obviously this also refers to simple non-competitive physical activity. Running, for example, can enhance synaptic activity through the production of BDNF, neuronal density in some brains, improve memory functions and even relieve anxiety. In humans, aerobic activity has been associated with hippocampal volume, higher plasma levels of BDNF, but provided it is done relatively far from highly polluted urban areas. Fine particles and toxic gases seem to prevent the production of BDNF, instead favoring inflammatory biomarkers especially cytokines such as IL-1 and IL-6.
What are foods and bioactives to keep the brain young?
Blueberries, although not widely consumed, are functional foods rich in polyphenols called anthocyanins. They are protectors of the vascular walls, they facilitate the microcirculation (also in the brain), they are antioxidants and partially anti-inflammatory. Several studies have confirmed that regularly consuming blueberries can reduce the risk of senile Alzheimer’s disease (vascular dementia). Turmeric has a similar action: this spice is rich in some polyphenols (curcumin complex) with a powerful anti-inflammatory, antioxidant and also anticancer action. It has been proven that the consumption of turmeric delays the brain deposition of beta-amyloid and can stimulate neuronal stem cells to form new neurons (neurogenesis).
Another polyphenol that preserves brain functions is luteolin, widely represented in celery, peppers, carrots and light or yellow vegetables, with an inhibiting action on inflammatory reactions in the brain. Cocoa and green tea are also functional foods: they are both rich in catechins, anti-inflammatory polyphenols, antioxidants that have been shown to promote brain function against age-related cognitive decline. The complex catechins of cocoa (pro-anthocyanidins) are powerful antioxidants and promote memory in human volunteers and in those with initial memory deficits, in a similar way to how the complex polyphenols of Gingko biloba do. So, in addition to protecting neuronal cells, they also improve blood circulation in the brain.
Finally, there are some vitamins that promote the well-being of the nervous system and whose deficiency can compromise certain cognitive functions. One of these is certainly vitamin B12: it enters the metabolism of carbon units to synthesize nucleic acids, repositories of genetic information. Furthermore, it dialogues with the metabolism of folic acid and methionine, the amino acid from which choline, noradrenaline and the stabilization processes of myelin are derived. The other is vitamin D, which stimulates the synthesis of nerve growth factors (NGF, BDNF) useful for maintaining memory, because they stabilize the synapses between brain cells. Furthermore, the inverse relationship between brain levels of vitamin D and depression is known: this vitamin, in fact, stimulates the synthesis of the enzyme tyrosine-hydroxylase which is the first step for the synthesis of brain dopamine.
Fish is naturally rich in omega-3s, so it is among the first places in a healthy diet aimed at preserving mental functions. It is also rich in iodine, which regulates brain function through thyroid hormones. Walnuts and almonds follow, which also contain phytosterols, a lot of vitamin B6, magnesium and vitamin E. Almonds have a lot of vitamin B2 (riboflavin), which helps the energy metabolism of brain cells and together with vitamin E is an antioxidant against damage related to ageing. If you like nuts, but want to avoid cholesterol, you can use cashews. Taking walnuts and almonds together is synergistic, because almond proteins are rich in phenylalanine, the precursor of norepinephrine and dopamine, which are the two main neurotransmitters of good mood.
And how much is it worth having a stable baseline mood to stay healthy?
- Edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
Tong EH et al. J Nutr. 2021 Sep 4; 151(9):2800-2807.
Romanidou M et al. Maedica (Bucur). 2020; 15(4):521.
García EE et al. Int J Epidemiol. 2019; 48(6):1914.
Luciano M et al. Neurology 2017; 88(5):449-55.
Kim B et al. Prev nutr Food Sci 2016; 21(4):297-309.
Voss MV et al. Trends Cogn Sci 2013; 17(10):525.
Erickson KI et al. Neuroscientist 2012; 18(1):82-97.
Su HM et al. J Nutrit Biochem 2010; 21(5):364-73.