Citrus fruit
According to the journal Nutrition and Metabolism, researchers there studied 70 patients who suffered with high blood pressure (hypertension). They gave one group of patients a placebo capsule daily over a period of six months; the other group received antioxidant capsules, containing vitamin C and E, coenzyme Q10 and selenium.
The tests, taken at the beginning, three months in and at the end of the six months, produced clear results: the antioxidant group saw decreased blood pressure, improved cholesterol and blood sugar levels, and had better arterial flexibility. Arteries become less flexible, or 'hard', when fat in the form of cholesterol, for example, is deposited on the arterial walls, building up over time and making it more difficult for the heart to pump blood around the body.
According to the researchers, antioxidants work by alleviating damage to the arteries caused by an overproduction of reactive oxygen species (ROS). These are molecules containing oxygen which are produced naturally by the body, as a byproduct, when we metabolise oxygen. Although they can be beneficial – when they are used by the body’s immune system for attacking pathogens, for example – if there are too many of these molecules it can lead to cell damage. It’s this damage that the antioxidants work to prevent.
So what should you do to protect your own heart health? Eat. "Although the study did not investigate the effects of a diet containing these antioxidants, incorporating these foods into a heart-healthy diet will certainly do you good!" says registered nutritionist Carina Norris, author of The Food Manual (Haynes, £19.99).
- Vitamin C: "The body can’t store vitamin C, so it’s a good idea to get it regularly through food," says Norris. "Raw sweet red pepper is an even better source of the C vit than an orange, and strawberries, Brussels sprouts and broccoli are also good."
- Vitamin E: "You don’t need this daily as your body stores it,” says Norris. “Good sources are olive oil, avocados, nuts and seeds."
- Coenzyme Q10: "Your body can produce some coenzyme Q10 itself, the rest we get from food," says Norris. "Good sources include sardines, mackerel, liver and eggs."
- Selenium: "Fish, Brazil nuts and lean red meat are good sources of selenium," says Norris. "And if you do take a supplement, remember that the safe upper limit is 0.45mg or less per day (including what you get from food) and an excess of selenium can cause health problems."
First published July 7, 2010