Life Extension Magazine February 2003
Anti-Cancer Foods and Supplements
Cancer is, perhaps, one of our greatest fears. Compounding our concern about contracting the disease is the fear of treatment. Few medical treatments inflict so much toxicity, mutilation and pain on the human body. Once a diagnosis is made, a person's life will never be the same.
Even when treatment is successful, a person can be disfigured from the effects, and parts of their body destroyed. The chance of a recurrence is ever present and years after successful treatment, cancer can come back even more virulent than before. Even after enduring conventional therapy, a large number of cancer patients still succumb from cancer cells that escaped the initial treatment.
A cancer diagnosis humbles a person of any means. Hospital gowns don't look any better on rich people than they do on poor, and chemotherapy feels the same. The degree of inconvenience, disruption and destruction of not only the ill person's life, but of those around them, should give any person pause to consider what they can do to avoid it.
The National Cancer Institute (NCI) issued an unprecedented number of press releases in the year 2002 stating that diet has a major impact on cancer. Deleting things from one's diet, as well as adding to it makes all the difference. What follows is some of the research behind the NCI's announcements-research that is convincing mainstream scientists to take another look at the anti-cancer benefits of compounds that occur naturally.
What you choose to eat largely determines whether or not you will get cancer. In his book Eat to Beat Cancer, J. Robert Hatherill points out that Japanese smoke like crazy (more than Americans), yet have the world's lowest rate of lung cancer. They also have the greatest life expectancy on earth. Clearly, they're doing something right. While there are many factors that affect longevity, the one that researchers are currently focusing on is diet. We know that diet plays a big role in cancer. It has been estimated that bad diet is responsible for 60% of all cancers. A good diet can prevent 20% to 50% of all cancers, according to most estimates.
What is a "good diet?" Research shows that it's a diet high in plant-based foods (fruits, vegetables, grains, legumes). A "bad diet" is one that's mostly animal-based foods (meat, dairy products) and synthetic food (prepackaged "convenience" food). Plants contain vitamins, minerals and phytochemicals that block, stop and suppress cancer. Animal-based food contains the highest concentration of cancer-causing chemicals that humans are exposed to, along with saturated fat and lots of calories. "Convenience food" is more product than food-full of calories, mostly devoid of nutrition. It's also contaminated with many chemicals that make it look good on the shelf.
Research into diet and cancer is getting so advanced that scientists are beginning to link what a person eats with the type of cancer they get. Other researchers are going the other way: pinpointing specific things in the diet that prevent cancer from occurring. For example, researchers at the University of Utah investigated the connection between carotenoids and colon cancer. They found that lutein, but not other carotenoids, is associated with lower risk. Similarly, researchers in the Netherlands found that folate, vitamin C and beta-cryptoxanthin (but not lutein and other carotenoids) are protective against lung cancer. The information from these kinds of studies is stacking up.
Phytochemicals (naturally occurring in plants) are the main defense against all types of cancer. As an example of how powerful they can be, it was recently estimated that prostate cancer in Greece could be reduced by two-fifths by merely increasing the consumption of two things: tomatoes and olive oil. (Dairy products should be simultaneously decreased, according to the report.) Another group reports that over 51% of ovarian cancers could be avoided if women would eat more green vegetables. This is an amazing figure. It underscores the tremendous impact diet can have on cancer.
Phytochemicals have different actions and different ways of protecting against cancer. Most are antioxidant, in other words, they scavenge damaging free radicals. This action also protects DNA. Others protect methylation which is critical for the activation of cancer-suppressing genes. Still others enhance immunity or impede the growth of abnormal cells.
Antioxidants and cancer
Human bodies are constantly exposed to chemicals, radiation and other phenomena that generate free radicals. Free radicals rip through cell membranes and slam into DNA, damaging it. Cancer cells are essentially normal cells that contain damaged DNA. Antioxidants stop free radicals and reduce DNA damage. This is why they are a major defense against cancer.
All antioxidants are not all the same. Some are better at stopping certain kinds of free radicals than others. For example, I3C (indole-3-carbinol) and a supplement known as "chlorophyllin" (a semi-synthetic version of chlorophyll) have excellent effects against free radicals generated by chemicals called heterocyclic amines. Heterocyclic amines are created when food, especially meat, is cooked over high heat. Studies show that I3C and chlorophyllin can stop this type of free radical up to 100%.
They can also protect against the highly-carcinogenic mycotoxin known as "aflatoxin." Aflatoxin is produced by a fungus that infects grains, notably corn. In studies on rodents, both I3C and chlorophyllin inhibit liver cancer caused by this toxin. A study from a region of China where the incidence of liver cancer is very high shows that 100 mg of chlorophyllin three times a day reduces DNA damage caused by aflatoxin by 55%. The researchers predict that taking this supplement will push back the onset of this type of cancer from 20 years to 40.
I3C and chlorophyllin work in another related way. They keep the liver from metabolizing carcinogens, including heterocyclic amines. It is the body's own metabolism of the chemicals in its effort to detoxify them that makes them carcinogenic. I3C apparently works through one type of enzyme, while chlorophyllin works through another. A combination of the two may eliminate more radicals than either alone.
Some antioxidants are better at preventing certain types of cancer than others. Vitamin C, for example, can inhibit skin cancer by 25% to 50% when applied directly to the skin. It does not have the same effect against breast or prostate cancer. But lycopene, a flavonoid from tomatoes, has antioxidant activity against prostate cancer. Beta-carotene, a carotenoid, appears to protect against breast cancer, but not against lung cancer. Having this type of information about specific antioxidants can help a person choose one that may target a certain type of cancer, or target a specific type of carcinogen. For those without risk for any particular type of cancer or exposure to any specific chemical, it would be prudent to take a variety of anitoxidants in order to block as many types of free radicals as possible.
Carotenoids and cancer
Studies show that people who eat a lot of red, orange, green and yellow vegetables have a significantly decreased risk of various cancers. The protective effect is due to carotenoids. Most people are familiar with the carotenoid beta-carotene, found in carrots. There are, however, hundreds of other carotenoids-some not even discovered yet. There is lutein in spinach, zeaxanthin in corn and lycopene in tomatoes. One of the purposes of carotenoids is to act as sunscreen for the plants they occur in. It's not surprising then, that carotenoids provide antioxidant protection, especially against free radicals generated by radiation.
Lycopene is the most abundant carotenoid in humans. The prostate gland alone contains 14 to 18 different metabolites of lycopene in people who eat tomatoes or other vegetables that contain it. Studies show that men who get the most lycopene in their diet have the lowest risk of prostate cancer. The two largest studies involve 14,000 Seventh-Day Adventists (lacto-ovo vegetarians) and 47,894 American physicians. In the physician study, men with the highest level of lycopene in their blood had a 20% reduction in risk. In the Adventist study, eating tomatoes more than five times a week reduced risk of prostate cancer by 40%. Lycopene is good at protecting lymphocytes from DNA damage. In an Italian study, 7 mg/day of lycopene reduced DNA damage 50% in the first week.
Carotenoids work synergistically. Taking several together is better than taking one alone. In the now infamous study where smokers took beta-carotene supplements and nothing else, risk of lung cancer actually rose. But a 30% reduction was found in a study of 100,000 people who ate a variety of carotenoids on a consistent basis rather than just one. A 60% reduction was found in the same study for non-smokers. It appears that alpha-carotene, not beta-carotene, is the best carotenoid against lung cancer.
Folic acid and cancer
This vitamin has been involved in so many important cancer studies that it stands in a class of its own. Folic acid (the vitamin version of folate) is a B vitamin typically found in certain green vegetables and legumes. Meat contains very little of it. A serving of steak, for example, contains 3% of the RDA, while a serving of broccoli contains 50%.
Folate has powerful cancer preventive effects through its role in maintaining methylation. Methylation has two powerful roles in preventing cancer. First, it is crucial for the repair of mutations. Second it is crucial for the activation and deactivation of genes involved in cancer. Folate is one of the required factors for methylation. Without it, methylation will fail, and cancer will result. Abnormal methylation is present in all cancers, no matter the type. The critical importance of folate, then, becomes apparent.
Lung and colon cancer are the first cancers to be linked to folate deficiency. Breast, prostate and pancreatic cancer involve the deficiency as well. Alcoholism, folate deficiency and breast cancer go together. The same is true for colon cancer-alcoholism exacerbates folate deficiency.
Research into the folate-cancer connection is just beginning. More information about folate's cancer preventive effects will undoubtedly emerge in the next few years.
Flavonoids and cancer
Quercetin, ellagic acid, apigenin and luteolin are powerful anti-carcinogens from plants. These exotic-sounding phytochemicals counteract cancer at its earliest stages. Apigenin, for example, interferes with the way estrogen is metabolized. When apigenin is present, estrogen stays in its weak form, unable to accelerate cancer growth. Luteolin prevents cancer-promoting estrogen from getting into cells. Several of the flavonoids suppress COX-2 (cyclooxygenase), an enzyme that enables cancer to grow and spread. COX-2 has been in the news because it's the enzyme targeted by certain antiinflammatories that inhibit cancer and other degenerative diseases as well.
In addition to these cancer-blocking actions, flavonoids possess powerful antioxidant activity that protects DNA from damage better than vitamin C.
Some flavonoids come from the family of aromatic herbs and shurbs known as labiatae. The labiatae include many of the herbs traditionally regarded as medicinal such as rosemary, mint, lavender and thyme. Labiatae plants provide a concentrated source of flavonoids with anti-cancer properties. Scientific studies are beginning to prove that flavonoids from these plants have very diverse and powerful effects against cancer. For example, in a study on melanoma in mice, apigenin and quercetin were equivalent to tamoxifen in inhibiting metastases. In studies on human leukemia, luteolin and other flavonoids stopped the growth of these cells in culture. Flavonoids can also inhibit enzymes which enable cancer to invade surrounding tissue and spread to other parts of the body.
Cancer-fighting flavonoids are also found in citrus fruit, tea and other plant-based foods. Certain flavonoids in citrus fruit known as polymethoxylated flavonoids work at the molecular level to counteract cancer. Tangeretin, for example, restores cell communication so that cancer can be brought under the body's control. Nobiletin, a similar flavonoid, causes human leukemia cells to differentiate into normal cells. Dozens of studies have been done showing that these flavonoids have powerful and diverse effects against cancer cells. The net effect is to wipe out cancer cells as soon as they appear.
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