OPTIMIZE YOUR HEALTH
Protecting Your Vision

True Colors of a Cancer Prevention Diet
By Jannet Huang, MD, FRCPC, FACE, ABHM

The foundation of a cancer preventing lifestyle is sound nutrition. Most experts agree that a predominantly plant-based diet is key to providing cancer-fighting nutrients. A nutritional advisor for the American Institute for Cancer Research advises that two-thirds of the food on our plate should be plants. Read on for a list of cancer preventing foods!

Folate-Rich Foods

This B-complex vitamin can be found in many 'good for you' foods such as spinach, asparagus, Brussels sprouts, peas and dried beans. When someone has low levels of folate, it's more likely for mutations in DNA to occur. Conversely, adequate levels of folate protect against such mutations.

A study showed men who consumed at least the recommended daily allowance of folate — about 400 micrograms — cut by half their risk of developing pancreatic cancer.

Vitamin D

Researchers suggest that vitamin D curbs the growth of cancerous cells.

A report presented at the latest meeting of the American Association for Cancer Research (AACR) showed a link between increased vitamin D intake and reduced breast cancer risk. It found vitamin D to lower the risk of developing breast cancer by up to 50%. Vitamin D has also been found to have protective effects against colorectal and prostate cancers.

In light of these recent findings, many researchers consider the current RDA of 400 international units (IU) too low. Researchers have suggested that the recommendations for vitamin D intake be increased to 1,000 IU for both men and women. Higher amounts may eventually prove better, but for now that amount is likely to be safe and have a protective effect. A blood test for 25OH-Vitamin D level can detect vitamin D deficiency and guide the dosage required for an individual.

While vitamin D is often associated with milk, high concentrations also can be found in these seafood choices: cod, shrimp, and Chinook salmon. Eggs are another good source. With the avoidance of sun exposure and use of sunscreen for skin health, many people have insufficient vitamin D levels and require supplementation.

Tea

Like many plant-based foods, tea contains flavonoids, known for their antioxidant effects. One flavonoid in particular, kaempferol, has shown protective effects against cancer.

A large-scale study evaluating kaempferol intake of more than 66,000 women showed that those who consumed the most of it had the lowest risk of developing ovarian cancer. Researchers suggest that consuming between 10 milligrams and 12 milligrams daily of kaempferol — the amount found in four cups of tea — offers protection against ovarian cancer.

A separate study showed a link between consuming flavonoids and reducing the risk of breast cancer. The study, analyzing the lifestyle habits of nearly 3,000 people, showed that postmenopausal women who got the most flavonoids were 46% less likely to develop breast cancer than those who got the least.

Cruciferous Vegetables

Cruciferous vegetables — members of the cabbage family that include kale, turnip greens, cabbage, cauliflower, broccoli, and Brussels sprouts -- can help you ward off cancer.

Recent studies on cruciferous vegetables show promising results against prostate and colon cancers. In mice grafted with human prostate tumors and then treated with one of these cancer-killing substances, tumors began to shrink to half their size after 31 days. Read about cruciferous vegetables in supplementation form.

Curcumin

Experts credit curcumin's anti-inflammatory effects for its ability to fight cancer. Recent studies have shown curcumin to interfere with cell-signaling pathways, thereby suppressing the transformation, proliferation, and invasion of cancerous cells.

Ginger

This popular spice, long used to quell nausea, may soon be used to fight cancer, too. Working directly on cancer cells, researchers discovered ginger's ability to kill cancer cells in two ways – by inducing apoptosis (programmed cell death) in cancer cells; and autophagy where cancer cells are tricked into digesting themselves. Research with ginger against ovarian cancer is ongoing.

Tomatoes

Epidemiological studies suggest that the risk of prostate cancer is decreased in men who consume four or more weekly servings of tomato products.

The mechanism by which tomatoes exert these protective effects is not exactly known, but is hypothesized to be from the potent antioxidant lycopene. Lycopene is the pigment that gives tomatoes their red color. Lycopene has the most potent antioxidant activity of any common carotenoid; it might reduce cancer risk by scavenging free radicals and quenching singlet oxygen, which prevents oxidative damage to DNA. In vitro, lycopene inhibits the proliferation of breast cancer, lung cancer, and prostate cancer. There is also some evidence that decreased serum or tissue lycopene concentrations might increase the risk of developing prostate cancer. Read about carotenoids in supplement form.

The American Institute for Cancer Research offers this list of tips to lower cancer risk in addition to not smoking or using tobacco in any form:

• Choose a diet rich in a variety of plant-based foods
• Eat plenty of fruits and vegetables
• Maintain a healthy weight and be physically active
• Drink alcohol in moderation, if at all
• Select foods low in fat and salt
• Prepare and store foods safely

Sources: WebMD, Medscape, The American Institute for Cancer Research

—September 2007

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