by Karen Collins, MS, RD, CDN

American Institute for Cancer Research

Q: Can people who are already overweight reduce their cancer risk if they lose weight?

A: Most adult cancers develop over a 10 to 20 year period or longer. Although researchers can’t say for sure that losing weight will lower cancer risk, the evidence looks promising. For example, two large studies of post-menopausal women found that those who lost weight after menopause reduced their risk of breast cancer substantially.   That’s important since a recent report estimated that overweight and obesity in the U.S. account for 14 percent of men’s cancer deaths and 20 percent of women’s.

When overweight people lose weight, they may not be able to undo cancer-causing damage that’s already done, but shedding excess fat can reduce elevated levels of insulin, insulin-related growth factors and certain hormones like estrogen.   As these compounds are all associated with the process of cancer development, we expect that their cancer-promoting effects also decrease with weight loss.   Each loss or gain of excess body fat seems to change cancer risk. Even if you can’t reach what you consider your ideal weight, researchers say that any excess body fat that you can lose and keep off should lower cancer risk.  

Q: Are mushrooms a good source of vitamin D?

A: Most mushrooms supply only a trace amount of vitamin D.   However, emerging research suggests that exposing mushrooms to ultraviolet light for a few hours before harvest (or 5 to 15 minutes after harvest) can trigger production of vitamin D within the mushroom.   “Enriched mushrooms” treated in this manner contain 23 to 85 micrograms (mcg) of vitamin D per three ounce serving, about one raw portabella mushroom piece or 4 large white mushrooms.   When converted to International Units (IU) – the measure most commonly used to record vitamin D levels in the U.S. – the figures are equivalent to roughly 900 to 3000 IU. It’s an amount that satisfies most people’s vitamin D requirements for a few days (based on current U.S. recommendations) and is even enough to meet the possibly increased standards being debated by health professionals.

Q: If I order my burger or sandwich without cheese, am I really saving that many calories?

A: Adding full fat cheese to your sandwiches and burgers usually adds an extra 60 to 100 calories and 5 to 7 grams of fat.   So, yes, ordering these foods without the cheese can be a good move.   However, if you consume less than the recommended amount of calcium each day – three cups of milk, yogurt or equivalent calcium-fortified foods – you may prefer to include the cheese and limit other sources of fat.   For example, you can usually cut more fat and calories by choosing a burger that is smaller or leaner (like turkey or veggie burgers) than by omitting the cheese.   Leaving off bacon saves about as much fat and calories as skipping cheese, too. You can also balance the fat in cheese by skipping the fries or chips that often come with these foods.

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The American Institute for Cancer Research (AICR) is the cancer charity that fosters research on the relationship of nutrition, physical activity and weight management to cancer risk, interprets the scientific literature and educates the public about the results. It has contributed more than $86 million for innovative research conducted at universities, hospitals and research centers across the country. AICR has published two landmark reports that interpret the accumulated research in the field and is committed to a process of continuous review. AICR also provides a wide range of educational programs to help millions of Americans learn to make dietary changes for lower cancer risk. Its award-winning New American Plate program is presented in brochures, seminars and on its Web site, www.aicr.org. AICR is a member of the World Cancer Research Fund International.

Publication Date: September 29, 2008              

Contact: Sarah Wally, (202) 328-7744