Do Antioxidants Prevent Cancer?

Natural antioxidants are the best

How effective are antioxidant supplements in preventing cancer?

Antioxidants: How Effective Are They in Preventing Cancer?

Antioxidant supplements have not been proven to effectively prevent cancer as studies at this stage are still inconclusive.

Can antioxidants prevent cancer? What about antioxidant supplements, how effective are they? Read on to find out.

Normal body functions such as breathing or physical activity, as well as unhealthy lifestyle habits such as smoking and drinking alcohol, all produce free radicals that attack healthy cells. When your cells are weakened by free radicals, they are more susceptible to developing certain types of cancers.

Antioxidants are a broad range of compounds that destroy free radicals. Many of these compounds are present in the diet as vitamins. The best known antioxidants are vitamin A, vitamin C and vitamin E.

Natural antioxidants are the best

The best way to get antioxidant vitamins is through healthy eating habits.

Fruits and vegetables contain essential vitamins, minerals, fibre and other nutrients including antioxidants. A good start to optimal health is to eat two servings of fruits and two vegetables a day (you can think of a "serving" as about a fistful).

Individuals who have diets rich in fruits and vegetables may have a reduced risk of cancer compared with those who eat a much higher proportion of high-fat and processed foods.

To have an idea of what to put on your plate daily, click here.

How effective are antioxidant supplements in preventing cancer?

Numerous studies have examined the association between dietary antioxidant intake and the risk of cancer. The results of these studies are summarised below. Surprisingly, it has been found that antioxidant supplementation for some disease groups may increase cancer risk.

Antioxidant supplementation and cancer prevention: Results based on randomised trials

Experimental Intervention	Sample Size	Duration of Study	Characteristics of Participants	Study Outcome
B-carotene: 15mg/day Vit E: 30mg/day Selenium: 50mcg/day	29,584	6 years	Malnourished age: 40 - 69	Lowers cancer rate
B-carotene: 20mg/day compared to atocopherol: 50mg/day	29,133	5 - 8 years Average 6 years	Male smokers age: 50 - 69	B-carotene: 20mg/day associated with increased risk in lung cancer in people who smoke and/or are exposed to asbestos
B-carotene: 30mg/day and retinyl palmitate: 25 000IU/day	18,314	4 years	Male and female age: 45 - 74 Smoker and/or occupational exposure to asbestos	No clear evidence of benefit
B-carotene: 50mg on alternate days	22,071	11.6 - 14.2 years, average 12 years	Male age: 40 - 84 Current/former or non-smokers	No clear evidence of benefit or harm related to cancer risk
B-carotene: 50mg on alternate days	39,876	0.00-2.72 years, median 2.1 years	Female age: > = 45	No significant difference in incidence of cancer
B-carotene: 25mg/day Vit C: 1000mg/day Vit E: 400IU/day	864	4 years	Adenoma diagnosed Good health Age: < 80	No clear evidence of benefit
B-carotene: 50mg/day	1,805	5 years	Recent non-melanoma skin cancer	No clear evidence of benefit