Alcohol and Cancer Risk, Phytochemicals in Grapes, and Calcium in Fish

Alcohol and Cancer Risk, Phytochemicals in Grapes, and Calcium in Fish

Q: Does alcohol increase cancer risk even in people who aren’t big drinkers?
Q: Are red grapes higher in protective phytochemicals than green grapes?
Q: If salmon is a good source of calcium, does the same apply to other fish?


Karen Collins, MS, RD, CDN
American Institute for Cancer Research

Q: Does alcohol increase cancer risk even in people who aren’t big drinkers?
A: According to AICR’s landmark 2007 report on diet and cancer prevention, excess alcohol consumption increases risk of cancers of the mouth, throat, esophagus, colon and breast and probably the liver as well. Alcohol’s effects on the body are numerous. Alcohol enhances the ability of carcinogens to get into cells and create DNA damage that can promote cancer development. In addition, alcohol is broken down into acetaldehyde, which scientists believe may act as a carcinogen. Excessive alcohol consumption also seems to decrease our ability to absorb and use folate, a B-vitamin needed to keep our DNA in good repair. Alcohol’s relationship to breast cancer in particular seems to involve its impact on folate as well as its ability to raise estrogen levels. For utmost protection from cancer, the best advice would be to avoid alcohol. But for those who choose to drink alcohol, keeping it to no more than one standard drink per day for women and no more than two standard drinks per day for men seems to be reasonably safe. (Women are advised to stick to a lower limit than men because alcohol becomes more concentrated in their bodies). A standard drink is a 5-ounce glass of wine, 12 ounces of beer or a 1.5-ounce shot of 80-proof liquor such as whiskey or vodka.

Q: Are red grapes higher in protective phytochemicals than green grapes?
A: Not necessarily. Grapes contain a variety of antioxidant phytochemicals and their content varies with growing conditions. Red grapes, for example, are higher in anthocyanidin, a flavonoid responsible for the fruit’s ruby pigment, but green grapes are higher in other antioxidants. Although red wine has a higher concentration of the phytochemical resveratrol than white wine, this is not an indication that green grapes are lacking in the antioxidant compound. Rather, the grape skins, which provide most of the resveratrol, are discarded earlier in white wine production than red, lowering the content.

Q: If salmon is a good source of calcium, does the same apply to other fish?
A: Salmon is only a good source of calcium if you eat the bones. Three ounces of drained canned salmon – bones included – provide 190 to 235 milligrams (mg) of calcium, equal to the amount provided in about 5 ounces of milk. This is roughly equivalent to 20 percent of the recommended daily calcium intake. Without the bones, however, a similar 3-ounce serving offers just 6 to 12 mg, roughly 1 percent of the recommended daily amount. In addition to salmon, sardines and anchovies are other types of fish that are frequently eaten with bones intact. Sardines are also an excellent source of calcium, supplying 325 mg in 3 ounces. And, while a 3-ounce portion of anchovies provides almost 200 mg of calcium, most people eat these strong-flavored fish in smaller amounts, which supply only 50 mg or so of calcium.

Reprinted with permission from the American Institute for Cancer Research www.aicr.org