Oxygen. We all know we need it to simply subsist, but what exactly is it doing in our bodies, how does it work biochemically within our cells, and can we eat to boost our own oxygen levels with real food?

Let’s start first with the basics. Your body absorbs oxygen every time you take a breath – air flows in through your mouth (and nose), down the throat into small little passages that extend all the way into the lungs (bronchioles), and finally descends into air sacks in the lobes of the lungs (alveolus). There, oxygen is passed through the very thin membrane walls and into the pulmonary capillary where your blood snatches it up, oxygen binds to the hemoglobin in your red blood cells, and whooshes off to be delivered to all your vital organs, your muscles, brain, you name it. The red blood cells return carbon dioxide which you then expel back out the same way, from your lungs up through the bronchioles and out through your mouth.

Too little oxygen, either because of a medical condition, inactivity, strenuous activity, illness, or environmental situation, can result in confusion, fatigue, even loss of consciousness. Even if you don’t feel the symptoms off the bat, too little oxygen (or hypoxia) starves your cells of the life force they need to ward off free radicals and to fully power your body’s functions and detoxification.

If you want to boost your body’s oxygen intake and uptake, incorporate these real, whole foods into your weekly meal planning:

Blueberries

Touted as one of the most antioxidant-rich foods, the sweet, juicy blueberry plays an important role in boosting your body’s ability to circulate and use oxygen. In addition to protecting cells against free radicals, antioxidants (like the flavonoids in blueberries) make it possible for the body to use oxygen more efficiently – essentially aiding the body in absorbing oxygen into the bloodstream in proper amounts. Not only that, but blueberries are a low-calorie food with loads of vitamins and minerals too including fiber, Vitamins C and K, as well as manganese. What’s even better than store-bought blueberries? Wild blueberries! They are believe to contain even more antioxidants and health-promoting nutrients than blueberries you find in a grocery store.

Walnuts

Walnuts boast loads of Omega-3 fatty acids, specifically alpha-linolenic acid (ALA), which not only help lower LDL, or “bad cholesterol” levels, but increase the amount of oxygen your hemoglobin can carry in your bloodstream. One ounce of walnuts also contains around 7% of your daily recommended value of fiber which aids digestion and helps you feel fuller longer. Add in appreciable doses of protein, Vitamin B-6 and magnesium, and a small serving of walnuts makes for one of the healthiest snacks around.

Red Kidney Beans

Not to be confused with red adzuki beans, red kidney beans are a versatile legume with a substantial health record on nutrition. When we mentioned above how oxygen enters your blood system by binding with your hemoglobin, it’s important to note exactly what molecule it is that oxygen binds with in hemoglobin – they are called heme. Heme are iron-containing molecules, making the mineral, iron, vital to healthy oxygenation. Where can you find hefty doses of iron? You guessed it, red kidney beans! In addition to iron (21% of your daily recommended value per boiled cup), red kidney beans generate substantial plant-based protein (30% of your daily recommended value in a boiled cup), as well as vasodilating potassium (20% of your daily recommended value in a boiled cup) which can help lower blood pressure.

Fish Oil

Remember when we were talking about Omega-3 fatty acids before? These brain and heart-boosting nutritional components also play an important role in fighting inflammation. Overwhelming inflammatory responses associated with illnesses like acute respiratory distress syndrome and asthma can lead to decreased oxygen diffusion in the blood as well as added stress to the lungs, which have to work harder to support the body’s oxygen needs. One 2009 study showed an omega-3 fatty acid (or n-3 polyunsaturated fatty acid) fish oil supplement improved oxygenation and reduced mortality of patients in the ICU with acute respiratory distress syndrome.

Lemons

A common addition to detoxification cleanses, the sweet, tangy lemon plays an important role in the oxygen-boosting process of alkalinization. On the pH scale where 0 is totally acidic and 14 is completely alkaline, the body wants to fall on the moderately alkaline side between 7.35 and 7.45 to remain healthy. Unfortunately, the SAD (standard American diet) incorporates large portions of acidic foods that can throw the internal pH off balance – meat, processed foods, dairy, dairy, alcohol, and most grains fall on the acidic side. Fresh fruits and vegetables, like lemons, alkalinize in the body and help balance acid levels in the bloodstream which boosts oxygen uptake to cells.

Water

This one seems like a no brainer, water contains oxygen so drinking it should help boost oxygen levels, right? Actually, yes. Not only does staying hydrated help regulate blood pressure, but it aids your body in eliminating waste and toxins through the liver and kidneys. Water boosts cellular respiration in the body, helps prevent constipation, and also flushes bacteria out through your bladder. According to the Harvard Medical School, the average adult should drink between 30 and 50 ounces of fluids a day, but you’re likely even safer sticking with the 8 glasses a day method most people have grown up hearing.

Dark Leafy Greens

Like the red kidney bean, dark leafy greens including spinach and kale, contain crucial iron which improves your body’s ability to absorb and circulate much-needed oxygen. Spinach is exceptionally versatile in that it can go with both sweet and savory dishes, i.e. add spinach to a health eggwhite scramble or throw it in a superfruit smoothie. Some evidence suggests that cooking spinach even slightly helps break up some cells and release more antioxidants than eating spinach in the raw, and because spinach contains non-heme iron, cooking it can unlock some of the inhibitors that prevent it from being more easily absorbed by the body. Sautee on!

How do you know if you’re getting enough oxygen? The amount of oxygen your blood is getting out of the amount of oxygen it should be absorbing is called your oxygen saturation level – healthy levels being between 95 and 100%. You can most easily measure your oxygen saturation levels with even the best fingertip pulse oximeter, or go a step further to test hemoglobin strength, acid/base levels, and levels of other gases in your blood with an arterial blood gas test from your doctor. If your oxygen levels fall below 92% saturation you’re entering dangerous territory – practice deep breathing to boost levels and seek immediate medical treatment if levels do not go back up.

In addition to eating oxygen-rich foods, regular exercise that helps you maintain a healthy weight and fight heart disease is important to boosting your body’s ability to uptake and circulate oxygen. A strong heart is able to pump oxygen-carrying blood more readily around your body, while maintaining a healthy weight with fresh fruits and veggies helps foster a normal pH balance, helps you stay active, and even wards off risks for diseases like diabetes, cancer, and Alzheimer’s.