The Scientific Evidence of the Beneficial Properties of Chestnuts, Nuts and Almonds

During an event hosted by ABNC – Brazilian Association of Nuts, Chestnuts and Dried Fruits, last April 27th., Brazilian experts presented the results of their studies.

During the webinar promoted by ABNC, Dr. Euler Ribeiro, Cardiologist, Pulmonologist, Geriatrician and Rector of the Open University Foundation of the 3rd Age (UNATI), accompanied by Dr. Ivana Beatrice M. da Cruz, Director of Biogenomics Research at the University of Santa Maria-RS, presented data on "The Scientific Evidence of the Beneficial Properties of Chestnuts, Nuts and Almonds".

The studies started in 2008 when the Open University of the State of Amazonas carried out a major research project to evaluate the lifestyle, health, and longevity indicators of the elderly who lived in the highly urbanized area of ​​Manaus, and riverside citizens of Maués, a municipality that has 175 communities distributed on the banks of rivers and streams.

At the beginning of the research, Maués had almost twice the number of long-lived elderly – over 80 years old – compared to other municipalities in the Amazon, and the first comparative study found that this population had a lower prevalence of obesity, diabetes, stroke, cancer and hypertension, and other diseases. Based on these data, the researchers began to investigate four major factors that impact health and longevity: genetics, functional fitness related to physical activity, stress, and nutrition and found little genetic influence, but excellent functional fitness.

Then, the researchers began to investigate the influence of the Amazon Diet, based on the consumption of cassava and corn by-products, as well as a wide variety of fish, on the health and longevity of these riverside dwellers. At that time, it was found that this riverside population also consumed a wide variety of fruits, a fact that led to a survey of scientific evidence related to 20 Amazonian fruits, which gave rise to the book “Dieta Amazônica”, authored by Dr. Euler Ribeiro and Dr. Ivana Beatrice. The publication, in addition to stimulating countless Brazilian and international studies on the subject, brought a new view on the foods consumed in the forest that started to be recognized as part of the “Amazon Diet”.

Brazil nut

From 2016, researchers began to develop studies on Brazil nuts, one of the most popular fruits in the Amazon region, recognized for its nutritional characteristics, consumed fresh or in the form of flour, milk, and oil. The daily consumption of 2 Brazil nuts, rich in macro, micronutrients, and bioactive molecules, provides an energy value of 38.8 calories, less than a glass of skim milk or an apple, for example, and, due to its high concentration of fat, the nut promotes high satiety without affecting body weight. The researchers also highlight fat as one of the main nutritional components of this nut, which contains a large amount of unsaturated fatty acids beneficial for health, such as omega 3, which has anti-inflammatory properties and represents 7% of the total fat of the fruit.

Regarding proteins, Brazil nuts are an excellent source of essential amino acids, such as leucine, which stimulates muscle protein synthesis and helps prevent muscle atrophy, common in the elderly, and methionine, which strengthens the immune system. The fruit is also rich in important bioactive molecules such as polyphenols, phytosteroids, phytates, and tocopherol that have antioxidant, anticarcinogenic, and anti-inflammatory activity. Additionally, the consumption of two nuts contributes to the daily intake of micronutrients such as phosphorus, potassium, magnesium, and calcium.

Selenium

One of the most well-known and important elements of Brazil nuts is selenium, found in great concentration, mainly in the peel that surrounds the innermost part of the fruit and which, according to epidemiological and experimental evidence, plays an important role in human health.

However, the researchers warn that these studies reinforce the idea that both poor and excessive daily intake of selenium are not beneficial for health, stressing that the daily consumption of two Brazil nuts would be the best option for maintaining the level, particularly when compared to supplements available in pharmacies, avoiding the risks of an inadequate concentration in the body.

Another highlight of the discussion was the relationship of the potential effect of selenium on viral infection caused by Covid-19. Quoting articles published by Norwegian researchers claiming that an adequate supply of some micronutrients, such as selenium, is essential to enhance strength against other infections and decrease inflammation, as well as specialists from the United States, Australia, and the United Arab Emirates, who demonstrated the immunomodulating effects of selenium and fatty acids to fight Covid-19, this supplementation is deemed to help to protect against the new coronavirus.

Supporting this case, the researchers also presented data from an experimental study carried out by professionals from China and the United States showing a strong inhibitory effect of selenium on the enzyme that allows SARS-CoV-2 to mature within cells and spread, and an analysis carried out in Germany – which compared patients who survived and those who died from Covid-19 – that found that those who died had a lower concentration of selenium in their blood.

Based on this evidence, the researchers suggest that the consumption of chestnuts, walnuts, and almonds proves to be a good dietary strategy to strengthen the immune system in the fight against Covid-19.

Nuts and health

The potential effect of nuts on human health and longevity was also addressed by Dr. Euler and Dr. Ivana Beatrice. Source of bioactive molecules, such as micronutrients, lipids, and polyphenols, among others, nuts prevent cardiovascular and neurodegenerative diseases improving the blood lipid profile without affecting body weight or blood pressure, according to international clinical trials, and contribute to improving cognitive function and memory, as well as reducing the risk of diabetes.

Other benefits have also been pointed out in international studies, such as the action on gastrointestinal disorders, chronic inflammation, and also the antitumor potential of the nut, due to its intrinsic chemical composition, in the fight against breast and prostate cancer, among others.

In their final remarks, experts reinforced the characteristics of chestnuts, nuts, and almonds as great allies for maintaining health and quality of life throughout human aging.