Antioxidant-rich foods and nutritional supplements help protect cells from free radicals, but excessive intake can harm your health. Free radicals are the main causes of aging and adult diseases like hypertension and osteoporosis.
Health supplements such as lycopene, omega-3 fatty acids and vitamin C can boost antioxidant levels, along with the so-called "superfoods" such as aronia berries, cacao nibs and acai berries.
"Many people only take certain nutritional supplements or eat too many antioxidant-rich foods," said Park Min-sun at Seoul National University Hospital. "It is advised to watch your overall intake of nutritional supplements, as they may not work well or even cause diseases."
Some people eat nothing but supplements while skipping meals, but it's important to maintain a balanced diet. "A lack of carbohydrates and fat can harm cardiovascular function, physical strength and blood circulation," Park said. "Some people who eat only fruits and vegetables rich in antioxidants and vitamins actually see their immunity levels drop."
Vitamins C and A are typical antioxidants that people often take in excess. "Taking too much vitamin C can cause diarrhea, kidney stones and arrhythmia," said Im Seung-gil at Yonsei University's Severance Hospital. Healthy people shouldn't take more than 1,000 mg of vitamin C a day. "If you consume too much vitamin C, the risk of a hip fracture grows to 40 percent," Im said.
The recommended daily intake of vitamin A is 3,000 international units (IU). In particular, pregnant women should avoid taking too much vitamin A, as it increases the risk of fetal deformities. Even in healthy people, the prolonged excessive intake of vitamin A can cause liver damage.
Eating differently colored foods ensures a healthy mix of antioxidants. "One meal should contain more than four different colors," said nutritionist Shim Sun-ah. Yellow fruits and vegetables are rich in beta-carotene, while green-colored ones contain sulforaphane and lutein. Red-colored foods are abundant in phenolic compounds, white ones in quercetin and purple ones in anthocyanin and resveratrol.
It is important to take health supplements that are appropriate to your specific needs while maintaining a balanced diet. "People in their 20s and 30s, who usually engage in a lot of activity, need more vitamin C, while those in their 40s to 60s need vitamin E, which helps prevent blood clots. People aged over 60 should focus on nutrition that can be supplemented from certain foods which they might not usually eat," Shim said.