Why You Need to Eat Blueberries

5 min readApr 7, 2021

The Battle Between Antioxidants and Free Radicals

Free radicals are atoms that contain one or more unpaired electrons. Now, you may be thinking: ew this sounds like chemistry. Let’s just pretend we have a free radical that’s dog and you just snatched his favorite toy from his collection. That dog is now mad, likely barking, and will obsess over its return. Free radicals aren’t so dissimilar. First, when an atom is missing one or more electrons, it’s incredibly unstable and reactive. Second, free radicals will do whatever it takes to steal one or more electrons.

Now, you’ve likely been taught “stealing is bad” but this expression takes on another form when it comes to electrons. Free radicals will destroy lipids, proteins, and even DNA to capture an electron. This process is said to foster “cancer, autoimmune disorders, aging, cataract, rheumatoid arthritis, cardiovascular and neurodegenerative diseases” (1).

To elaborate, when free radicals steal an electron from a base in DNA, this is called a lesion and such a modification may be cancerous. When a cell is damaged, it sends up a flag to yell for help. In response, other cells are called to the site to participate in an inflammatory cascade. For example, mast cells create that itchy, sneezy sensation. This cascade also calls on chemokines to direct cellular traffic. Free radicals also recruit Kappa B (a protein) which can increase inflammation, adhesion molecules (plaque), and apoptosis (cell suicide).

At this point, you should be thinking: oh my god these things can cause cancer?! Get them out of me! In homeostasis, the population of free radicals is low thanks to population control. Remember the title of this article? Blueberries, along with other berries, are chock-full of antioxidants. Antioxidants are like vultures on the scavenge: they’re always scanning for their prey and once they spot a free radical, they neutralize the threat by donating an electron. When an antioxidant gives away its electron, it oxidizes and is fired from its job as population control. Therefore, we constantly need to replenish antioxidants by supplementing our diet with foods like blueberries.

When there is a moderate to low population of free radicals, they serve a beneficial role. For example, they’re great 911 operators and soldiers. When you have a wound, free radicals can recruit platelets (type of blood cell) to the site of injury. Similarly, the immune system utilizes free radicals because what’s a better way to fight infection than a cell-destroyer, right? Finally, free radicals are known to be intercellular messengers and can induce mitosis (cell division).

On the flip side, when we lack antioxidants, the body can suffer from oxidative stress. Oxidative stress just means an imbalance of free radicals and antioxidants. Free radical populations are affected by both exogenous and endogenous factors. For example, pollution, cigarette smoke, and radiation are all external sources of free radicals that can pass into the body. Internally, we produce free radicals through “enzymatic” and “non-enzymatic” ways.

A number of enzymatic processes like producing prostaglandins (hormone-like compounds) and cytochrome P450 enzymes (hormone breakdown) or even when a cell swallows something (“phagocytosis”) can produce free radicals as a byproduct. Furthermore, non-enzymatic processes like metabolic oxidation or the actions of the Central Nervous System (CNS) similarly produce it as a byproduct.

First, let’s talk about oxidative phosphorylation (a form of metabolic oxidation). Now, when you hear mitochondria, we hope that you immediately thought the powerhouse of the cell!. The mitochondria breaks glucose into water and CO2 by snapping the bonds to release energy. Snapping the bonds is actually a result of transferring electrons. Now, we hope you’re immediately thinking not electrons again! Occasionally, electrons “escape” from this process and our good friend, the free radical, is formed.

Second, stress triggers free radical mass production. You may have heard of a “fight or flight” reaction. This is synonymous with the sympathetic nervous system. Let’s pretend for a moment that a ghost is chasing you. You’re probably feeling your heart race, pupils dilating, mouth watering, and a burst of energy. This burst of energy is actually a result of release of a bunch of neurotransmitters like epinephrine, norepinephrine, and cortisol. When that ghost is finally gone, those neurotransmitters actually degenerate into free radicals.

We also want to note that Type II Diabetes has been shown to increase free radicals in a number of studies. Diabetes is characterized by high blood sugar levels. Type II Diabetes is classified by insulin resistance which leads to these high levels. Now, you’re probably scratching your head thinking what’s insulin?.

Normal Blood Glucose Regulation with Incretin and Insulin

Say you’re eating a delicious marshmallow. Once ingested, the sugars in that sweet are broken down into the simplest form — glucose — which enters the bloodstream. Normally, for those who don’t have diabetes, a hormone called incretin calls up the pancreas and says yo we got sugar!. The pancreas then says oh hell no and commands its β-cells to start producing insulin. Now that insulin is on the run, it orders tissues to start sucking in glucose for storage and the liver to stop producing glucose.

For those with Type II diabetes, three things may have gone wrong. First, they may have peripheral insulin resistance which means those tissues are ignoring commands to store sugar. Second, they may have hepatic insulin resistance which means the liver is ignoring all commands to halt glucose output. Finally, incretin may not be doing its job in signaling the secretion of insulin.

Dysregulation of insulin can lead to the rise in blood sugar levels. This, in turn, stimulates the generation of free radicals. As we’ve seen previously, when the population of free radicals rise or we have a lack of antioxidants, we can have serious damage to our fats, proteins, and DNA. Whether diabetic or not, it’s important to always keep your antioxidant stores up so they can moderate free radicals. That’s why you need to eat — or keep eating — those blueberries!

TL;DR: Oxidative stress is an imbalance between free radicals and antioxidants. Free radicals are atoms that are missing at least one electron and will destroy cells to snag one. Antioxidants can neutralize the threat by donating an electron. It’s super important to keep free radical populations controlled and one of the best ways to do this is by eating antioxidants. Blueberries are one of the most anti-oxidant-rich foods so keep on eating them!

References:

Why You Need to Eat Blueberries

Written by Nicole Trappe