Even though it is unclear how most phytochemicals work, their beneficial effects are apparent. So for now, variety is the key and the more the better.
Apple / grapes / cherries / straw berries: The soluble fibre in apples lowers the blood sugar. These fruits contain ellagic acid though to fight cancer by blocking an enzyme used by cancer cells.
Cabbage family: There is strong evidence that member of the brassica family (cabbage, cauliflower, broccoli, Brussels sprouts) can stand guard against disease. The beta-carotene, indolesglucoinnolates and isothiocyanates (found particularly in broccoli) in these vegetables may prevent certain cancers.
Chilies/peppers: It was presumed that chilies could damage your stomach. But experts now believe that the mild irritant effect of chilies may stimulate the stomach’s defenses; they may protect the stomach from alcohol and other irritants, helping to prevent ulcers and cell damage. & Also they are good source of vitamin C & anti oxidants. Capsaicin, the stuff that gives chilies their fire, is antioxidants, which can neutralize free radicals.
Citrus fruits: orange, sweet lime, grape fruit, lemon etc. are packed with vitamin C, bioflavonoids and limonene which is being studied for its effects on breaking down carcinogens (cancer causing substances) and stimulating cancer fighting cells
Garlic and onion family: the allicin in garlic lowers the bad LDL cholesterol and triglycerides and raises the good HDL cholesterol in blood. It drops blood pressure levels, boosts immunity and has antibiotic properties. Allium compounds are also found in onions, spring onion, leeks, chives and shallots. as also helps in heart & liver disease.
Green tea: research indicates that green tea may have anti cancer effect. It seems that polyphenols (a class of antioxidant) should take the credit, and in particular, catechins. This food has also shown promising results for heart and liver disease.
Leafy greens: like spinach, fenugreek, amaranth, lettuce, parsley, celery, are an excellent source of beta-carotene. Besides some of them also provide calcium, iron, folic acid, vitamin C and nutrients. Glutathione, active ingredient in spinach safeguards against cancer.
Oats: an excellent heart medicine. About ½ cup of dry oat bran or a cup of dry oatmeal puts a dent in your blood cholesterol and regulates blood sugar level.
Oily fish: such as mackerel, salmon, tuna, sardines, herring, lake, trout contain omega-3-fatty acids. These help protect against heart attacks by making clot formation less likely. Omega-3-fatty acids also protect against diabetes, cancers, and inflammatory and autoimmune diseases like arthritis, psoriasis and ulcerative colitis.
Olive/ rapeseed oil: too much of any fat is bad, but replacing saturated fats with unsaturated fats, especially monounsaturated (MUFA), is beneficial. Olive and rapeseed oil are both rich in MUFA.
Papaya/ carrots: these, like all other yellow/ orange fruits and vegetables like pumpkin, mangoes, apricots, sweet potatoes, squash are full of beta carotene & vit-C. papaya is rich in enzymes which aid digestion.
Soya products: Soya beans, Soya flour, Soya milk and tofu are low fat & calcium rich. Soya products rich in genistein have been linked to lower rates of certain cancers.
Tomatoes: contain lycopene, a caritenoid, which has cancer resistance effects. They also contain coumaric acid and chlorogenic acid, which flush out carcinogens.
Yogurt: studies have shown that yogurt containing live bacteria is good for digestion. Being a good source of calcium, it is helpful against osteoporosis later on in life.
So go ahead, include these in your diet & look young.