Almighty antioxidants have earned the halo of health from the medical field. These compounds, found in a multitude of fruits, vegetables, and other plant-based foods, fight everything from cancer to stroke … or do they? A new study from Harvard Medical School, published online in the journal Neurology, found that an antioxidant-packed diet may not prevent dementia and stroke. Rather, some antioxidants pack more of a punch than others.

Antioxidants are vitamins, minerals and other nutrients that defend and heal cells from damage caused by free radicals. They can bolster the body’s defense against everything from the common cold to cancer.

The Harvard study investigated the antioxidant-eating habits of more than 5,000 people in the Netherlands who were at least 50, and tracked whether they had suffered a stroke in the past 14 years. The study found no connection between the level of antioxidants consumed … but a similar study conducted in Italy suggested otherwise. The key could be what types of antioxidants you ingest. The question is, does the level of total antioxidants indicate stroke and dementia risk, regardless of what types of foods you eat?

Coffee or tea consumption contributed to almost 90 percent of the inconsistency in antioxidant levels among the Dutch subjects, whereas Italians got most of theirs from eating fruits and vegetables. Other studies have suggested that indeed eating plenty of greens, roots and fruits helps prevent an array of diseases and conditions. The typical Dutch diet includes mostly meat, dairy, coffee and tea, but amping up veggie intake could be beneficial.

The three main antioxidants are beta-carotene, vitamin A and vitamin C. You’ll find them in carrots, asparagus, kale, broccoli, mango, papaya … and the list goes on. Just fill your plate with the rainbow and you can’t go wrong.