Dusičnany v zelenine: Komplexný pohľad na ich vplyv na zdravie

Dusičnany sú prirodzene sa vyskytujúce zlúčeniny, ktoré sa nachádzajú v rôznych potravinách, najmä v zelenine. Dlhodobo sa diskutuje o ich vplyve na ľudské zdravie, pričom sa objavujú protichodné informácie. Tento článok sa zameriava na komplexný pohľad na dusičnany, ich zdroje, metabolizmus v tele a potenciálne zdravotné účinky, s osobitným dôrazom na ich prítomnosť v zelenine.

Čo sú dusičnany a kde sa nachádzajú?

Dusičnany (NO3-) sú soli kyseliny dusičnej (HNO3), známe aj ako nitráty. Vyskytujú sa prirodzene v pôde, vode a rastlinách ako súčasť kolobehu dusíka. Človek ich prijíma v potrave, ale telo ich dokáže aj syntetizovať.

Skupiny potravín, ktoré prirodzene obsahujú veľké množstvo dusičnanov, sú zelenina a ovocie. Medzi zeleninu s najvyšším obsahom dusičnanov patria:

  • Listová zelenina (špenát, šalát, rukola, kel)
  • Červená repa
  • Zeler
  • Reďkovky
  • Mrkva
  • Baklažán
  • Listy kvaky

V živočíšnych potravinách býva obsah dusičnanov veľmi nízky, výnimkou sú mäsové výrobky, do ktorých sa dusičnany alebo dusitany dostávajú pri solení mäsa. Nájdeme ich preto najmä v spracovaných a údených výrobkoch.

Metabolizmus dusičnanov v tele

Po prijatí dusičnanov v potrave dochádza k ich metabolizácii v tele. Dusičnany sú metabolizované niektorými druhmi orálnych baktérií na dusitany (NO2-) a tie na oxid dusnatý (NO) v procese zvanom denitrifikácia. Približne 25 % prijatých dusičnanov sa vylučuje slinami do ústnej dutiny. Koncentrácia dusičnanov nalačno v slinách sa pohybuje v rozmedzí 100-500 μM, čo je približne 10-krát viac ako v krvnej plazme.

Je to spôsobené tým, že slinné žľazy človeka aktívne vychytávajú dusičnany z krvnej plazmy a sekretujú ich do slín. Oxid dusnatý sa absorbuje do krvného obehu a v tele pôsobí ako signálna molekula podieľajúca sa na kardiovaskulárnej a metabolickej regulácii.

Vplyv dusičnanov na orálny mikrobióm

Dusičnany ovplyvňujú zloženie a fungovanie mikrobiálnych spoločenstiev v prírodnom prostredí. Je prekvapujúce, že sa doteraz výraznejšie neskúmal ich efekt na orálny mikrobióm. Tieto látky sú dlhodobo spájané so schopnosťou stimulovať tvorbu zdraviu prospešných orálnych bakteriálnych rodov a majú tiež potenciál znižovať rody spojené s kazom, paradentózou a halitózou.

Štúdie preukázali, že biofilmy pestované s dusičnanmi obsahovali niekoľkonásobne vyššie hladiny rodov baktérií Neisseria a Rothia, ktoré sú rodmi redukujúcimi dusičnany. V nedávnych štúdiách boli rody Neisseria a Rothia spájané s jedincami bez chorôb. Boli častejšie v subgingiválnom plaku u periodontálne zdravých jedincov v porovnaní s pacientmi s paradentózou.

Okrem toho boli viac zastúpené v supragingiválnom plaku jedincov bez kazu v porovnaní s jedincami s aktívnym kazom. Čo sa týka bakteriálneho zloženia súvisiaceho s chorobou, bol pozorovaný pokles rodov Veillonella, Streptococcus a Oribacterium, ktoré sú spojené s acidifikáciou a zubným kazom.

Jockel-Schneider Y. a kol. v nedávnej štúdii zistili, že konzumácia stravy bohatej na dusičnany po dobu 2 týždňov tiež zlepšuje zdravie ďasien.

Oxid dusnatý (NO), ktorý vzniká z dusičnanov, reguluje mnoho dôležitých bunkových funkcií vrátane regulácie zdravého prietoku krvi a zdravej hladiny krvného tlaku, komunikáciu medzi bunkami v mozgu a tiež to, ako sa naše telo bráni proti patogénom. Oxid dusnatý uľahčuje prietok krvi uvoľnením krvných ciev a uvoľňuje sval, čím napomáha zvýšenému prietoku krvi nevyhnutnému na vyvolanie a udržanie erekcie.

Erektilná dysfunkcia spôsobená týmto problémom je často symptómom a niekedy predchodcom kardiovaskulárnych ochorení. Často je erektilná dysfunkcia predznamenaná vysokým krvným tlakom. V prípade vzniku zápalu kdekoľvek v tele hrá NO kľúčovú úlohu, pretože zvyšuje prietok krvi do poranenej oblasti a zároveň zvyšuje priepustnosť stien krvných ciev.

Potenciálne riziká spojené s dusičnanmi

Dusičnany nie sú v bežných koncentráciách pre dospelých nebezpečné, pretože sa pomerne rýchlo vylučujú močom. Avšak, vysoký príjem dusičnanov v strave môžeme vnímať ako problém u malých detí do šiestich mesiacov veku. Tie ešte nemajú takú výbavu, ktorá by im umožňovala efektívne sa s dusičnanmi vysporiadať a to môže viesť k stavu zvanému methemoglobinémia. Jedná sa o postihnutie na úrovni krvného farbiva hemoglobínu, v dôsledku čoho krv nie je schopná dostatočne okysličovať tkanivá.

V tomto prípade však nie sú problémom mäsové výrobky, ale napríklad príprava kojeneckej výživy s vodou z vodovodu, ktorá je tiež významným zdrojom dusičnanov. Nitrozamíny sú karcinogény (látky, ktoré sa podieľajú na vzniku rakoviny) a vznikajú najmä vtedy, ak sú dusitany v kombinácii s aminokyselinami (bielkovinami) vystavené vysokej teplote.

Ak ste však tuhí fajčiari, tak máte oveľa väčší problém než ten, že si raz za čas dáte na rodinnej grilovačke opekanú slaninku.

Odporúčania pre príjem dusičnanov

Na elimináciu rizík by sme sa mali vyhýbať nadmernej konzumácii spracovaných mäsových výrobkov. Pár koliesok šunky alebo salámy, prípadne grilovaná klobása raz za čas samozrejme nie je pre zdravého človeka žiadny problém a určite mu to neuškodí.

Je dôležité uprednostňovať príjem dusičnanov z prirodzených zdrojov, ako je zelenina. Konzumácia pestrej stravy bohatej na zeleninu je kľúčová pre zabezpečenie dostatočného príjmu dusičnanov a ďalších živín, ktoré sú prospešné pre zdravie.

Dusičnany ako prebiotikum?

Výsledky štúdie jasne dokazujú, že dusičnan môže byť ekologickým faktorom stimulujúcim orálne rody spojené so zdravím, pričom má potenciál znižovať rody spojené s kazom, paradentózou a halitózou. Na základe uvedených zistení autori štúdie navrhujú, aby bol dusičnan molekulou spojenou so zdravím v ústnej dutine a mohol sa používať ako prebiotikum.

Nitric oxide is a gas naturally produced within the body that acts as a vasodilator, helping to improve blood flow. Proper blood flow is essential for optimal tissue and organ health. Specific foods and supplements can help boost the body’s natural nitric oxide levels.

What Is Nitric Oxide?

Nitric Oxide is a gas made naturally in the body by combining nitrogen and oxygen. Its main role is to support blood vessel health by helping dilate blood vessels, raise blood supply, and lower blood pressure.

Vasodilation is the widening of blood vessels, which allows more blood to flow through the vessels. Nitric oxide works by relaxing the inner muscles of blood vessels, allowing them to widen and increase blood flow. Healthy vasodilation is important for optimal health, as it allows oxygen and nutrients to reach tissues and organs within the body, supporting their function.

As a supporter of blood vessel health, nitric oxide offers a host of benefits throughout the body. Studies suggest nitric oxide may help decrease muscle soreness, treat erectile dysfunction, boost exercise performance, and even help manage type 2 diabetes. While nitric oxide cannot be found in supplements or foods, a number of supplements and foods support the body’s own production of nitric oxide.

Eating a diet high in antioxidants along with nitrate-rich foods can support nitric oxide production. Two amino acids, L-arginine and L-citrulline, which are found in some foods or as supplements, also support nitric oxide production. Studies show that a diet rich in naturally occurring nitrates may improve athletic performance and reduce your risk of chronic and diet-related diseases.

Conversely, eating a diet high in added nitrites or nitrates may increase the risk of disease. Many foods that naturally contain nitrates also contain antioxidants like vitamin C, which helps the body make nitric oxide instead of nitrosamines. When foods with added nitrates and nitrites-like commercially processed hot dogs, deli meats, bacon, and ham-are consumed, the nitrates break down into nitrosamines.

Nitrosamines are a known carcinogen and may increase the risk of certain types of cancer when consumed frequently. Eating processed meat has also been associated with various cancers, including colon, breast, liver, and lung cancers, as well as increased risk of diabetes and heart disease. To support healthy nitric oxide levels and reduce nitrosamines levels, eat vegetables that naturally contain nitrates and are rich in vitamin C, while minimizing or eliminating your intake of processed meats.

Top Foods to Boost Nitric Oxide

Nitric oxide gas is made from natural sources of nitrates and nitrites in our food, such as dark leafy greens, citrus fruits, meat, poultry, seafood, nuts and seeds, chocolate, and wine. By consuming a nitrate-rich diet, a person can naturally support their own nitric oxide levels.

Leafy green vegetables like spinach, along with kale, arugula, and Swiss chard, have higher nitrate concentrations than other vegetables. Spinach can be consumed fresh and eaten raw in salads, sandwiches, or wraps. Spinach is also excellent steamed as a side dish or cooked with eggs, soups, stews, or sauces.

You can also use spinach in baking, adding it to muffins or breads for a boost of iron, fiber, and nitrates! Lastly, spinach can also be purchased or stored frozen for convenience and to help prevent food waste. If you don’t get much spinach in your diet, you can still benefit from its nutritional properties through spinach powders or capsules.

Beets are a colorful root vegetable rich in antioxidants, fiber, and nitrates. Beets can be juiced raw for a colorful, hydrating beverage or fermented into sauerkraut, a gut-healthy condiment. Beets can also be baked in muffins, breads, cakes, pancakes, or waffles, providing a vibrant pink or red hue to your recipe! Beets are commonly peeled and cooked for soups, salads, or side dishes. For those who don’t enjoy the taste of beets, a beet powder supplement is an excellent way to conveniently and consistently benefit from the nutritional benefits of beets!

Naturally high in nitrates that support blood vessel health, studies suggest beets and beet powders may support athletic endurance and increase a person's ability to handle high-intensity exercise.

Garlic has many powerful medicinal properties, thanks to a natural compound in garlic known as allicin. Garlic is also a great source of nitrates, helping boost nitric oxide levels, even when consumed in small amounts! Garlic is mostly commonly enjoyed cooked and is often used in savory recipes, such as soups, stews, sauces, salad dressings, marinades, and savory baked recipes. Garlic can also be consumed in powder or capsule form.

Additional health benefits of garlic include immune function support, helping lower blood pressure and cholesterol levels, supporting athletic performance, gut health, and bone health, and possibly helping the body detoxify against heavy metals.

Carrots provide many health benefits, including supporting eye health, digestion, heart health, immune function, skin health, and healthy cholesterol levels. Carrots are rich in beta carotene, a compound that gives carrots their orange color and is converted into vitamin A within the body. Vitamin A plays many important roles in the body, such as supporting eye health, immune health, growth, development, and reproductive health.

Additional foods rich in beta-carotene include cantaloupe, pumpkins, mangoes, peaches, and apricots. Carrots are also fibrous vegetables and a source of nitrates.

Meat, poultry, and seafood are all sources of protein, an essential macronutrient for growth, development, bone health, muscle health, cognitive function, and weight management. Meat, chicken, and seafood are also great options for boosting nitric oxide levels. Processed meats contain higher levels of nitrates, often due to nitrates or nitrites added to the meat to help prevent bacterial growth.

Added nitrates or nitrates also give processed meat a pink or reddish hue. Therefore, fresh, quality meat, poultry, and seafood is a healthier option for naturally boosting nitric oxide levels. Pairing meats with fruits and vegetables rich in vitamin C can also help the body break nitrates down into nitric oxide. Baking, grilling, roasting, and steaming are all delicious ways to prepare meat, poultry, and seafood.

Dark chocolate is made with a higher percentage of cacao beans than white or milk chocolate. Cacao is not only delicious but also offers incredible health benefits, like supporting cardiovascular health, boosting mood, reducing inflammation, and supporting cognitive function. For those with a sweet tooth, chocolate is a wonderful choice for satisfying a sweet craving while supporting one’s health.

In addition to being a source of nitrates, cacao is rich in magnesium, iron, calcium, zinc, copper, potassium, manganese, and flavanols. Cacao flavonoids may help lower blood pressure, prevent clots, and support healthy blood flow to the heart and brain. Cacao can be enjoyed as a dark chocolate bar, dark chocolate chips, or cacao powder to mix into smoothies, baked recipes, hot chocolate, or even in savory recipes like mole sauce.

Citrus fruits may seem like an unlikely source of nitrates-but this water-dense, fibrous fruit is a great way to help boost the body’s nitric oxide levels. While there are many different types of citrus fruits, common varieties for snacking, cooking, and baking include oranges, tangerines, lemons, limes, and grapefruits. Citrus fruits are incredibly versatile for both sweet and savory recipes and can be used in cooking, baking, smoothies, desserts, popsicles, salads, or for snacking.

Another key health benefit of citrus fruits is their high vitamin C content. This powerful antioxidant nutrient is essential for helping the body break down nitrates into nitric oxide.

Nuts and seeds are a source of two main macronutrients-protein and fat-and fiber. Walnuts, almonds, pistachios, sunflower seeds, and chia seeds also contain nitrates. Walnuts, in particular, contain the amino acid L-arginine, which helps the body convert nitrates into nitric oxide. Nuts and seeds are great staples for gut health, heart health, and immune health. Nuts like almonds are also rich in the antioxidant vitamin E. Seeds like chia seeds are a source of omega-3 fatty acids, which support brain and heart health.

Celery is a water-dense root vegetable that is packed with fiber and is a source of nitrates. Celery is also a source of vitamin K and small amounts of calcium, iron, and vitamin A. Celery is a great snack with almond butter or peanut butter, diced in a salad, soup, or stew, juiced, or added to a smoothie!

Red wine, more so than white wine, is another source of nitrates, antioxidants, and resveratrol. Resveratrol is a natural phenol in red wine that has antioxidant and anti-inflammatory properties. While red wine may help increase nitric oxide levels in the body, it is still a source of alcohol, which provides no nutritional benefit. According to The World Health Organization (WHO), no amount of alcohol is considered safe for human consumption due to the long-term and well-documented negative health impacts of alcohol consumption.

Potential Symptoms of Low Nitric Oxide

Low nitric oxide levels impact blood circulation, reduce blood flow to the brain, organs, and tissues, and can result in symptoms such as:

  • Depression
  • Fatigue
  • Poor Sleep Quality
  • Reduced Libido
  • Poor Vision
  • Hypertension
  • Memory Loss

Takeaway

Nitric oxide is a vasodilator that supports healthy blood flow, which in turn supports the health and optimal function of all organs and systems within the body. Eating a diet rich in real, whole foods like fruits, vegetables, nuts, seeds, and quality, wholesome meat and seafood is a great way to help boost the body’s nitric oxide levels naturally.

Avoid eating nitrates or nitrites that are added to foods like processed meats. They break down into nitrosamines, which are known carcinogens and may increase cancer risk. To enjoy the health benefits of naturally occurring nitrates, add spinach, beets, carrots, garlic, poultry, seafood, dark chocolate, citrus fruits, nuts, seeds, and celery to your weekly grocery shopping cart!

tags: #špenát #absorbuje #dusičnany

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