How Many Antioxidant-Rich Foods Do You Need Every Day?

Oxidative stress may play a major role in the initiation and progression of some of our leading killers, and every meal is an opportunity to tip the body in a pro-oxidant or antioxidant direction. Chug some sugar water and the level of free radical generation goes up in your bloodstream over the next few hours as your body metabolizes the carbohydrate. Wait. Why would we evolve to have a negative reaction the very act of digesting our primary fuel? Because over the millions of years we evolved, there was no such thing as sugar water—all sugars and starches came pre-packaged with protective antioxidants. In nature, sugar always come with phytonutrients.

Drinking orange juice gives us less of an oxidation spike than a sugar water solution with the same amount of sugar, because the sugar in fruit comes with antioxidants as part of a package deal. We can’t just drink vitamin C enriched sugar water either, because it’s not the vitamin C in the OJ that’s helping but the citrus phytonutrients, like naringenin, named for the Sanskrit word for orange tree. Presumably, eating the whole fruit would have worked even better since fiber can also help. Two servings of a fiber cereal significantly reduced (but alas could not extinguish) the free radical bump induced by sausage and egg muffin breakfast. And don’t believe the pulp fiction—even “high pulp” OJ contains little or no fiber.

And, fat is even worse than sugar. Giving people straight fat (heavy whipping cream) produces more oxidant stress than even downing twice as much straight sugar (twice the hydrogen peroxide in the blood over the subsequent six hours and more than 50 percent greater free radical damage). That may be why the antioxidant defenses in our bloodstream are decreased after a high-fat meal. However, antioxidant-rich sources of fat, such as nuts or avocados, did not show the same detrimental effect.

Eating a single meal deficient in antioxidant-rich foods can leave us in a pro-oxidant state for hours, coinciding with a drop in antioxidants in our bloodstream, as our body’s stores are slowly used up. If you’re going to have a pro-inflammatory meal high in fat and refined carbs, like a bagel and cream cheese breakfast, adding the equivalent of two-thirds of a cup of sliced strawberries for dessert was found to help neutralize the free radical damage. Otherwise, without the fruit, by lunchtime we’d already be in oxidative debt and could just dig our hole deeper from there.

If we just ate healthy foods, we can get a boost in the antioxidant content of our bloodstream, as has been demonstrated with foods such as blueberries, red grapes, kiwifruit. “These data provide an interesting perspective for advising individuals on food choices when consuming a moderate-to high-fat meal is unavoidable.” What, like locked in a fast-food joint at gunpoint?) They suggest chasing whatever we’re forced to eat with some high antioxidant foods like berries. Reminds me of studies suggesting that smokers should eat lots of kale and broccoli to reduce the oxidative damage to their DNA. Of course, they could also just, not smoke.

In the very least, we should eat enough antioxidants to counter the oxidation of digestion. We don’t want to slide backwards every day and end up with less antioxidants in our bodies than we woke up with. So, the average person might need 11,500 micromoles of antioxidant power, which is more than achievable eating nine servings of some fruits and vegetables, but not others. And, that doesn’t account for any additional oxidant stressors like illness, or second-hand smoke, or air pollution, or sleep deprivation.

There was a remarkable study published in the Journal of Biomedical Optics detailing a novel experiment in which German researchers noninvasively tracked people’s antioxidant levels using an argon laser to measure, in real time, the fluctuating antioxidant levels in their skin. Their most important finding was that antioxidant levels can plummet within two hours of a stressful event, but may take up to three days to get back to normal. So, stay up all night partying or get stuck in traffic breathing diesel exhaust, and your body almost immediately starts depleting its antioxidant stores. Hours to lose, but days to recover; so, healthier eating is especially important when we anticipate we’ll be stressed, sick, or tired. Ideally, we would have antioxidant-rich foods at every meal and snack.