The Diet Cancer Story

>Low intakes of fruit and vegetables have been
consistently linked to high cancer rates in many
My wife has had 10 tumors removed from hercountries around the world. Yet, less than 10 per
breasts. The first two and the last two (1 eachcent of North Americans eat the recommended
breast each occurrence) were benign. The six in5-10 daily servings. The fruit and vegetables that
between (four in the right breast, two in the leftappear most protective against cancer are raw,
breast) were malignant. Although the diagnosis ofdark green leafy vegetables (such as spinach, kale
breast cancer is a devastating experience, mostand lettuce), cruciferous or cabbage-family types
women face up to and cope well with it. In fact,(such as brussel sprouts, cabbage, cauliflower,
studies show that many respond with renewedbroccoli), and orange forms such as carrots,
vigour and enjoyment of life and strongersquash, citrus and other fruits. Different plant
interpersonal ties. But there is an inevitable periodfoods may protect against different cancers, for
of adjustment, usually improved by knowing asexample:
much as possible about the disease.* dark green vegetables may protect against lung
My wife was been “free of cancer” for wellcancer;
over 5 years, but at her last mammogram* cruciferous (cabbage family) vegetables and
checkup they discovered a growth they could notcarrots appear protective against colon cancer;
otherwise account for and want to do another* citrus and other fruits rich in vitamin C may
byopsy-type lump removal. This inevitably raiseslower risks of mouth, larynx, stomach and
the heady and frightening spectre ofesophageal tumours.
“cancer” once again. As I write, thisThe constituents in plant foods thought to ward
“ectomy” is still in our future, so the resultsoff cancer include antioxidants - such as vitamins
and reactions are also “still in our future.C, E and carotenes (vitamin A precursors) - and
We’ve been there, several times, but thatstarches (which may protect against colon
won’t make a diagnosis of malignancy anycancer). Other plant compounds such as indoles,
easier, any less emotionally traumatic, evenflavones, phenols, coumarins, isothiocyanates,
though the “period of adjustment” is easedsterols and limonene may also play an anti-cancer
somewhat.role. Together, the plant components or
So after 8-9 years cancer free she wasphytochemicals that fight cancer have been
diagnosed in January, 2005 with another lump anddubbed "chemopreventive agents."
it was removed in early April, 2005. Yes, it wasThe possible "chemopreventive" role of
malignant, but, in the doctor’s words, itantioxidants
was a ‘friendly” tumor. Our “period ofThe cancer-combatting or chemopreventive
adjustment” has been much easier this timeeffects of fruit and vegetables are attributed by
around.some experts to antioxidants such as the
Cancer is the second leading cause of death incarotenoids or vitamin-A precursors. Their action
North America (after heart and otherin inhibiting cancer is ascribed mainly to the ability
cardiovascular diseases) with lung cancer headingto combat the oxidative hits that damage DNA
the list, followed by bowel, breast, prostate,and cell membranes. The carotenoids are red,
pancreas and other malignancies. Cancerorange and yellow pigments found in fruit and
prevention is therefore a top for healthvegetables such as cantaloupe, tomatoes, corn,
authorities. Of known cancer causes, smokingcarrots and peppers, as well as in green leafy
tobacco accounts for about a third of the casesvegetables such as spinach, brussel sprouts and
and diet is blamed for another 30-70 per cent,broccoli (where their orange/yellow colour is
although the relationship between food and cancermasked by the green pigment, chlorophyll). Some
is hazier than for tobacco, and there are no patcarotenoids are converted into active vitamin A
answers.(retinal) inside the body, others not.
In general, cancer risks can be diminished byHow about dietary supplements?
avoiding tobacco use, protecting skin fromSince certain constituents in fruit and vegetables
ultraviolet rays, limiting alcohol intake and -seem to reduce cancer risks, it is reasonable to
according to the latest evidence - by eatingwonder whether one should take supplements.
enough fruit and vegetables. Recent results fromWhile opinions vary, most nutritional scientists do
many studies link low intakes of fresh fruit andnot encourage use of vitamin or other
vegetables to high cancer rates. Somesupplements for cancer prevention. People can
researchers claim that inadequate intakes of fruitobtain all the necessary vitamins, minerals and
and vegetables double the risks of cancer atother essential nutrients from a well balanced diet.
many sites - as well as markedly increasing risksThere are no scientific grounds at present to
of heart disease and cataracts. Since only aboutsupport the anti-cancer benefits of taking vitamin
10 per cent of North Americans eat theor antioxidant supplements. "Besides the risk of
recommended amount of fruit and vegetables,toxicity from vitamin megadoses, there is the
there's ample room for improvement in fightingadded danger," notes one University of Toronto
cancer. (Very recent studies suggest thatexpert, "that people who take supplements may
anti-inflammatories, such as ASA/Aspirin andfalsely believe they are eating well, yet fail to
other nonsteroidals may help to prevent someachieve the health benefits of a balanced diet."
cancers.)In addition to the expense, those who take
Diet-cancer links are complex to unravelsupplements may neglect to eat the
As foods are complex mixtures and people makerecommended quota of fruit and vegetables, miss
wide and varied choices, it is hard to proveout on other valuable components and get less
definite relationships between food and cancer.effective health protection. The evidence for a
Much of what is known about the dietary causescancer-protective effect of individual supplements
of cancer comes from epidemiological studiesis far less convincing than that for fresh fruit and
(that examine the distribution and risks forvegetables as a whole. There is also concern
disease). Epidemiological comparisons of cancerabout the safety of antioxidant supplements.
rates in different countries and how they changeAlthough vitamins C, E and beta-carotene have
offer clues. When people migrate to a newlow toxicity, even when consumed in doses
country and mimic its lifestyle, they soon acquireabove recommended daily amounts, a few
the same cancer rates as those in the adoptedstudies suggest that consuming large doses might
country. For example, if Japanese people (whonot be safe.
have low rates of breast and colon cancer butLarge studies now underway will clarify the action
high rate so stomach cancer) move to the U.S.,of individual dietary components. The joint effect
they acquire typical American cancer rates - highof the many varied compounds in whole fruit and
colon and breast cancer rates, low risks ofvegetables gives far greater protection against
stomach cancer.cancer than any individual nutrient or supplement.
Studies reveal a picture of the diet-cancer link inFinally, remember that diet is basically worthless if
which some dietary constituents may promoteyou are not getting the proper nutrition from
certain cancers - such as fat (mainly from meat),your diet. If the basic nutrients from your diet are
excess energy (calorie) intake and heavy alcoholnot being used to help heal your body and
consumption - while other components, especiallymaintain overall health, you are wasting your time,
antioxidants in fruit and vegetables, may help toeffort, money and life. A healthy diet begins with
prevent cancer. Other dietary constituents thatproper and full nutrition.
may protect against certain cancers include fattyThe place to begin with your nutrition, the method
acids in fish (the N-3 or omega-3 fatty acids) andto get the most benefit out of the foods you
folic acid (a B vitamin). Large studies noweat, especially in our modern world with foods
underway should tell us in a few years whichrampant with antibiotics, poisoning of our lakes,
dietary components promote or combat tumourrivers and oceans (not to mention the land and
formation.air), is to make liberal use of both herbal dietary
The protective anti-cancer effects of fruit andsupplements and especially dietary aids such as
veggiesorganic greens.