A guide to antioxidant foods
When free radicals build up in a person's blood, they can create oxidative stress. Oxidative stress may increase the risk of developing cancer, heart disease, and many other chronic illnesses and health problems.
Many healthful foods contain antioxidants. If a person consumes some or all of these foods regularly, they may increase their antioxidant levels, potentially helping them prevent the damage that doctors associate with oxidative stress.
In this article, we list some of the most healthful foods that a person can eat to boost the antioxidants in their diet.
Studies on blueberries have shown that these fruits have beneficial effects as a result of their antioxidant content. For example, the authors of a review of animal studies concluded that antioxidants in blueberries might have medicinal uses for neurological conditions, including those that relate to aging.
A 2016 review examined the anthocyanins that occur naturally in blueberries and other plant materials. Anthocyanins belong to a group of chemicals that have antioxidant and anti-inflammatory actions. They are responsible for many of the bright colors of fruits and vegetables.
The review found that anthocyanins may help prevent high levels of low density lipoprotein (LDL), or bad, cholesterol, as well as lowering the risk of heart disease and decreasing a person's blood pressure.
2. Dark chocolate
Good quality dark chocolate has high levels of nutrients and antioxidants. Researchers have linked dark chocolate to a range of potential health benefits, including:
- lower risk of heart disease
- reduced inflammation
- less chance of high blood pressure
- promotion of good cholesterol
One review of 10 studies involving close to 300 participants showed that dark chocolate helps reduce both upper and lower blood pressure measurements.
The authors noted, however, that future research needs to determine how much dark chocolate a person should eat for these benefits and investigate its effect on other metabolic conditions.
Artichokes provide lots of nutrients and antioxidants. Research suggests that they may help lower people's cholesterol levels and improve their gut health.
One study looking at the medicinal use of artichokes over time noted that artichoke consumption can be good for gut, liver, and heart health.
Another study showed that chemicals in artichokes had an antioxidant effect on LDL cholesterol in laboratory tests. Therefore, regularly consuming artichokes may contribute to lowering a person's risk of cardiovascular diseases and other related conditions.
How people prepare artichokes makes a difference to their antioxidant levels. One study compared boiling, frying, and steaming to see how each affected the antioxidant levels.
The results showed that steaming increased the effectiveness of the antioxidants by 15 times while boiling increased it eightfold. Researchers believe the reason for this is that boiling and steaming break down the cell walls, making the antioxidants more accessible.
Pecans offer high levels of good fat, calories, minerals, and antioxidants.
One study showed that the body can absorb antioxidants from pecans, increasing their levels in the blood.
It also found that eating raw pecans helps lower the blood levels of oxidized LDL cholesterol, which may mean that these nuts help prevent heart disease.
Strawberries are rich in antioxidants, vitamins, and minerals. Strawberries owe their red color to anthocyanins, which have antioxidant powers.
A 2016 review showed that taking anthocyanin supplements reduced the levels of LDL cholesterol in participants with high cholesterol. By lowering LDL cholesterol levels, anthocyanins may help prevent heart disease.
People can consume raw strawberries as a snack or as part of a salad or other dish.
Although strawberries are an ingredient in some baked goods, these products are rarely healthful and are not a good choice for people trying to lose weight.
6. Red cabbage
Red cabbage contains many nutrients, including vitamins A, C, and K plus several antioxidants.
Red cabbage, like strawberries and red kale, contains anthocyanins. In addition to giving the vegetable its red color, this group of antioxidants helps promote heart health, prevent cancer, and reduce inflammation.
According to one study, anthocyanins have the following health benefits:
- diabetes maintenance and management
- promote weight control
- prevent heart disease
However, more research is still necessary to determine the health effects of eating red cabbage. A person can eat red cabbage as part of a salad or as a cooked vegetable.
Raspberries are an excellent source of many antioxidants. They also contain manganese, vitamin C, and dietary fiber. Evidence suggests that the antioxidants present in raspberries may help destroy certain cancer cells.
In the case of breast cancer, the researchers attributed some 50% of the cancer cell destruction to the antioxidant effects of the raspberry extract.
A more recent review of studies showed that the compounds in black raspberries might slow the progression of cancerous tumors.
However, most of the research on raspberries has involved experiments in test tubes. Consequently, researchers need to carry out studies involving people to judge the effectiveness of eating raspberries in preventing disease.
Research has shown that pinto beans could help in suppressing certain types of cancer.
Beans are an excellent source of protein and dietary fiber. Some beans, such as pinto beans, are also high in antioxidants.
Pinto beans contain a plant flavonoid called kaempferol, which may help suppress cancer cell growth and reduce inflammation. Several studies link kaempferol to the suppression of specific cancers, including:
Despite these promising studies, researchers do not know much about the antioxidant effect of kaempferol in humans. To date, they have primarily carried out studies in animals and test tubes.
However, as beans have several potential health benefits, it is a good idea for people to include them as part of their regular diet.
9. Purple or red grapes
Purple and red grape varieties contain vitamin C, selenium, and antioxidants.
Two of the antioxidants that occur in grapes, namely anthocyanin and proanthocyanin, may help protect a person from heart disease or cancer.
However, there is a need for additional research to show the exact effects that eating grapes has on heart health and cancer risk.
Spinach is a green, leafy vegetable full of vitamins, minerals, and antioxidants. It is low in calories, making it an excellent choice as an addition to salads and entrees.
Zeaxanthin and lutein are two of the antioxidants in spinach that may promote eye health. They help prevent damage from ultraviolet (UV) rays and other harmful light waves.
A review of studies on lutein and zeaxanthin noted that lots of studies have investigated their role in age-related macular degeneration. The authors also suggested how people could get more of these antioxidants in their diets, naming dark leafy greens, eggs, and pistachios as sources.
Beets are vegetables that contain antioxidants belonging to a class of pigments called betalains. Betalains may help prevent colon cancer and digestive issues.
One review noted that betalains show promise for reducing free radicals and helping prevent cancer. However, research has not yet determined the effectiveness of eating beets for these benefits.
Kale is rich in vitamins A, C, and K, and it contains several antioxidants. It is a popular health food and hardy winter vegetable, common in many northern regions.
Red kale may offer more than green kale because it contains anthocyanins.
Anthocyanins are antioxidants that are readily available in a variety of fruits and vegetables. They are responsible for the color of these foods, from vibrant red to blue.
13. Orange vegetables
Several orange vegetables contain vitamin A and other nutrients. These vegetables contain large amounts of phytochemicals that can help with heart disease and cancer prevention. Some examples of orange vegetables with high antioxidant levels include:
- sweet potatoes
- acorn squash
- butternut squash
There is limited evidence to suggest how best to serve orange vegetables. Often, people cook them, but a person can eat some varieties, such as carrots, raw as a snack or part of a salad.
There are many common foods that people can eat to increase the number of antioxidants that they consume.
The antioxidants in these foods may help promote heart and eye health, prevent cancer, and protect against other common diseases that scientists associate with harmful free radicals.
However, researchers still need to understand the extent to which each of these foods helps people acquire higher levels of antioxidants. They also need to determine how effective each is in disease prevention.