" first part
Tumors of the Digestive System
As we saw in the first part of the article, most diet-influenced cancers affect the digestive system; in addition, cancers of the breast, prostate and endometrium are also involved.
We will focus on the dietary and behavioral factors predisposing neoplastic diseases (leaving out the others such as comorbidities, genetics, etc.).
In practice, we will summarize everything that should be AVOIDED in the diet to prevent cancer.
Tumor of the esophagus
Barret's esophagus; it may be congenital, but in most cases it is triggered by the neglect of gastroesophageal reflux disease (GERD). See also Diet for Gastroesophageal Reflux
Stomach cancer
Cancer of the pancreas
Hepatocarcinoma
Colon cancer
Milk, Calcium and Cancer
Milk and tumors
In the past, it was hypothesized that milk could have a predisposing effect on cancers of the large intestine. Both recent studies and scientific reviews have completely disproved this theory.
Unlike the fatty and / or salt-rich derivatives, milk does not play any harmful role and on the contrary it could contain molecules useful for prevention.
Butyric acid, typical of milk, is considered an energy molecule for the cells of the intestine.
Furthermore, calcium (which is abundant in milk) binds certain inflammatory factors of bile acids (which would then be released into the intestinal lumen).
Bacteria from fresh fermented milks, such as yogurt, may have a probiotic function and safeguard the colon.
On the other hand, the data concerning the correlation between milk and prostate cancer are less encouraging. It seems that the link is actually present, not due to the presence of calcium (as was hypothesized), but to the intervention of hypothetical yet unknown bioactive compounds.
Regarding breast cancer, the data suggest caution. While milk does not seem in any way linked to the onset of this disease, fat derivatives can increase the chances of relapse in women who have already operated on for breast cancer.
In summary, the intake of milk and derivatives in the diet is recommended in the following doses:
- Milk and yogurt 2-3 servings a day of 125 ml / g.
- Cheeses 3 weekly portions: 50 g for mature and fatty ones, and up to 100 g for fresh and lean ones.
Calcium and tumors
The speech changes with regard to football.
Given its primary importance in skeletal development and health in general, it is imperative to stick to the recommended levels.
The general belief that “the more football you take, the better” is therefore denied.
The maximum intake, which for the human being concerns the female prevention of osteoporosis in old age, corresponds to 1500 mg / day. It is strongly recommended to avoid excesses considering that, in addition to milk and derivatives, this mineral is contained also in vegetables such as: cabbage, chicory, soy and derivatives, oil seeds and some fishery products (for example small fish to eat whole).
Anti Tumor Diet
Is there an effective diet to prevent cancer?
Just as there is no single food involved in the genesis of cancer, in the same way there is no "magic" food capable of protecting the organism from these diseases.
The protective role of certain nutrients, typical of certain categories of food, is however now certain, since it is supported by a "large amount of studies.
Vegetable nutrients against tumors
A diet rich in plant foods appears to reduce the risk of many cancers that affect the digestive and reproductive systems.
The function on the digestive system is linked above all to the antioxidant capacity and that on the reproductive system also benefits from an "anti-hormonal" action (they partially inactivate endogenous estrogens).
The directly involved molecules are:
- Polyphenols
- Phytosterols
- Phytoestrogens
- Phenolic acids
- Flavonoids
- Catechins
- Sulphides and above all
- Organosulfuric compounds
- Indoles
- Isothiocyanates
- Organophosphorus compounds
- Chlorophyll
- Monoterpenes and saponins
- Others.
Note: Most antioxidant nutrients also have a protective effect on cardiovascular disease. They are in fact capable of improving cholesterolemia, decreasing platelet aggregation, reducing arterial pressure and it is assumed that they have a positive effect on glycaemia and also stimulate immune function.
Polyphenols
That of polyphenols is a "wide range of molecules with a strong antioxidant and potentially antitumor power. The main classes are:
- Flavonoids or catechins: they are very common; celery, cabbage, broccoli, soy, tomatoes, all fresh fruit, red wine and tea contain good quantities of it
- Phenolic acids: the most indicative example is coffee, not necessarily intended as the powder of roasted seeds, usually used in Italy to produce the drink of the same name, but more generally as the seeds of the plant (see also raw green coffee) .
- Phytoestrogens: isoflavones from soy and lignans from oil seeds, as well as from whole grains and legumes; they are natural substances that seem to have a "protective action against breast and prostate cancer.
Organophosphorus compounds
Organophosphorus compounds present in Cruciferae (such as cabbage, broccoli, turnip greens and Brussels sprouts) have shown a protective effect against certain types of cancer, studied in vitro and in animal models.
Sulphides and organosulfuric compounds
The organosulfuric compounds (subgroup of sulphides) present in the Liliaceae (such as garlic, onion, shallot and leek) have shown an effect similar to the previous group; indoles and isothiocyanates have a marked anti-hormonal function
Chlorophyll
Chlorophyll contained mainly in green leafy vegetables; it has a sensibly antioxidant and therefore probably anticancer action.
Monoterpenes and Saponins
Monoterpenes are aromatic substances, present in citrus fruits and certain spices, which interfere with cell proliferation; in the tumor, this differentiation is usually accelerated and uncontrolled.
Some saponins, those that are abundant in legumes and cereals, promote the elimination of certain carcinogenic substances from the intestine
Others
Vitamin and mineral antioxidants, namely: vitamin A, vitamin C, vitamin E, zinc and selenium reduce oxidative stress, which is one of the main risk factors in the development of cancer
Furthermore
Soy, garlic, onion, shallot, tomato and derivatives, as well as foods or supplements that contain zinc, beta-carotene, vitamin C and calcium, appear to help prevent prostate cancer (see also: lycopene).
Mediterranean Diet Against Prostate, Pancreas and Endometrium Cancer
25% of cases of colorectal cancer, 15% of breast cancer and 10% of prostate, pancreatic and endometrial cancer could be avoided by adhering to the indications of the Mediterranean diet [Trichopoulou et al, 2000].
Some advices
- Avoid calorie excess and carry out regular physical activity in order to maintain a healthy weight and not get too heavy (no more than 5 kilos)
- Reduce the percentage intake of fats, particularly limiting the consumption of saturated, hydrogenated and especially trans
- Supplement the daily diet with foods rich in antioxidants (vitamins A, C, E, polyphenols, etc.) and fiber
- It is therefore advisable to include in the diet at least 4 portions a day of vegetables or fruit (equal to 600-800 grams), taking advantage of the varieties that the seasons offer
- Limit the intake of alcoholic and sugary drinks
- Limit the salt intake; it is better to stay below 8 g / day preferring aromatic herbs
- Significantly reduce the consumption of preserved foods, especially salted (cured meats, sausages, etc.) and smoked foods
- Avoid fried foods, prepared at high temperatures (see: best oils for frying) or over high heat (grilling)
- It is preferable to consume fish as an evening dish at least three times a week, cheese once or twice, eggs once and fresh meat only once or twice (once white and once red).
- It is advisable to consume legumes at least two or three times a week, as a side dish or as a substitute for the first or second course, perhaps associated with cereals (pasta and beans, rice and peas, etc.).
Cooking on the grill
Recommendations for grilling
- As we have extensively described in the first part, grilling dubiously healthy meat can be responsible for the increase in harmful, toxic and generally carcinogenic compounds. Therefore, it is necessary to follow some recommendations:
- Choose meat of good quality and of guaranteed origin; in this way it is possible to avoid at least in part the dangers that the toxic cooking residues are also associated with hormone residues or other carcinogenic substances used in livestock breeding
- Avoid the fattest cuts of meat, since it is above all the fat that undergoes harmful alterations with heat
- For the same reason, limit the excessive greasing of dishes during cooking
- Avoid consuming foods that are clearly charred or at least scrape off over-roasted parts. If the meat tends to stick, use "a drop of" extra oil "(without exaggerating) but it is absolutely necessary to avoid leaving dangerous toxic traces on food.
- Drink plenty of water to facilitate the elimination of toxins; avoid association with alcohol
- If possible, with grilled meat it is better to associate a fresh and raw side dish, not grilled cooked (for example grilled chop and salad). Preferring a cooked side dish (as well as toasted bread) further increases the amount of toxic compounds
- In general, in the diet, associate meat with foods rich in fiber and antioxidants, such as vegetables and fruit which, to fully exploit their antioxidant power, should preferably be eaten raw (with the exception of tomatoes)
- Avoid over-salting the dishes.
Sausages, nitrites and nitrates
If the following appears on the label:
- Nitrites (E249 E250): it is good to avoid or at least limit their consumption
- Nitrates (E251 E252): should be consumed in moderation, as they are less dangerous than the previous ones but not entirely safe
- Nitrates (E251 E252) in association with ascorbic acid (vit C) and / or citric acid: quite safe, thanks to the beneficial properties exerted by vitamin C (antibacterial action, inhibitory action on the transformation of nitrates into nitrites).
Avoid heating foods containing nitrates, as the heat facilitates their transformation into nitrites.
Probiotics and prebiotics
- The data available so far concern the reduction of colon cancer
- A possible explanation is given by the ability of lactobacilli to suppress the growth of bacterial species, which convert pro-carcinogens into carcinogens, thus reducing the concentration of carcinogens in the intestine.
- Furthermore, lactobacilli can sequester potentially mutagenic compounds in the intestine, thus preventing them from being absorbed.
- In addition to fructose, the main products that are formed by the fermentation process, by the intestinal microflora, of FOS (a particular type of prebiotics), are short-chain fatty acids such as acetic, propionic and butyric acid (which seem to have a preventive action in colon cancer etiology).