Q. If those chocolate nut spreads in the peanut butter section of the grocery store have the same number of calories as peanut butter, are they a good substitute for peanut butter?
A. In this case, the differences among these products is not the calories, it's what you get for the calories.
Plain peanut butter contains about 8 grams of protein per serving (two tablespoons) along with the healthy unsaturated fats contained in the nuts. Popular brands also add about 1 gram of saturated fat, ½ teaspoon of sugar and a pinch of salt in each serving. In that same 2-tablespoon serving, chocolate nut butters generally add about 2 teaspoons of sugar. Protein per serving is also lower, because it contains fewer nuts. The total fat content is lower but in this case, that's not a good thing: nuts' natural fat is a healthy fat, and there's less fat in these chocolate nut butters because the same size serving contains more sugar.
Some chocolate-flavored nut spreads may take this difference even further, containing more sugar and added oils than nuts. Again, calories and saturated fat may be the same, but you're getting less protein, less healthy fat and far more sugar than plain nut butters. Most of us have some room in our diets for treats, but it's best to consider the higher-sugar spreads a treat, not equivalent to peanut or other basic nut butters
Q. I know exercise helps reduce risk of breast cancer. What about breast cancer survivors?
A. We now have several studies following women diagnosed with early stage breast cancer (stages 1 through III) that link getting some physical activity each week with 35 to nearly 50 percent lower risk of recurrence or death over the average five to ten years that women were followed after diagnosis. Protection is seen regardless of type of cancer, menopause status or weight.
Even an hour of walking throughout the week is better than nothing and up to an hour a day of moderate to vigorous exercise is linked to even better odds of remaining cancer-free.
We have no evidence, however, that more than an hour or so of moderate to vigorous exercise daily provides any additional benefit. Physical activity could act in several different ways to reduce breast cancer recurrence, just as it reduces risk of an initial cancer: it tends to decrease levels of insulin and growth factors that can promote development of breast (and other) cancers, and it changes reproductive hormones, too.
Now, a new study suggests physical activity may affect gene expression, effectively "turning on" genes related to suppressing breast cancer tumors. Finally, although physical activity generally doesn't burn enough calories to produce much weight loss on its own, studies consistently find it a crucial part of long-term weight maintenance, which plays an important role in protecting against post-menopausal breast (and other) cancers.
• Provided by the American Institute for Cancer Research. Learn more about the group and its New American Plate Program at aicr.org.