December 29, 2008
Contact: Sarah Wally, (202) 328-7744

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

Q: Does green tea or green tea extract help people lose weight?

A: According to the National Center for Complementary and Alternative Medicine, there is not sufficient evidence to determine if green tea can aid in weight loss. In fact, the research is conflicting. In one 2007 study, obese men and women who were given green tea extract (but still maintained their usual diet and activity patterns) showed greater decreases in body fat and waist measurement than those given a less-active compound. But other research, including one 2008 study that followed participants for four months, has found no difference in weight loss or change in waist measurements between groups given green tea extract versus a placebo. If you want to see if it makes a difference for you, there’s no harm in including some green tea among your daily beverages. When used in moderation, potential side effects include caffeine sensitivity and possible interference with blood thinning medications due to a small amount of vitamin K. Drinking green tea is certainly more economical than choosing supplements or extracts since an eight-ounce mug costs about 17 cents and contains an equal amount of active compound found in the pills or powders. In the end, you are probably best advised to focus on finding small ways to cut calories and increase physical activity each day rather than rely on weight loss aids like teas and extracts.

Q: How does the amount of caffeine in espresso compare to the amount found in regular coffee?

A: Espresso is more concentrated in caffeine than regular coffee, but the standard serving is much less, so drink-for-drink the two are fairly comparable in caffeine content. A six-ounce cup of coffee contains about 70 to 120 mg of caffeine, while a standard one-ounce espresso shot contains about 70 mg. Portion size is key however. A 16-ounce coffee (considered a “medium” at many coffee chains) can provide up to 300 mg of caffeine. A double shot of espresso in a cappuccino or latte offers about 150 mg.

Q: Is it true that alcohol can affect blood pressure?

A: Maintaining a healthy blood pressure is dependant on several lifestyle influences, among them: weight control, regular exercise, limiting salt and sodium consumption, and getting enough potassium – particularly by eating a diet rich in vegetables and fruits. According to most experts, blood pressure control is usually not disrupted by alcohol, as long as it is consumed in moderation (no more than one standard drink a day for women and no more than two standard drinks a day for men). However, individuals can vary in how they respond to alcohol and should discuss it with their physician.

Our Mission: The American Institute for Cancer Research champions the latest and most authoritative scientific research from around the world on cancer prevention and survival through diet, weight and physical activity, so that we can help people make informed lifestyle choices to reduce their cancer risk.

We have contributed over $105 million for innovative research conducted at universities, hospitals and research centers across the country. Find evidence-based tools and information for lowering cancer risk, including AICR’s Recommendations for Cancer Prevention, at

All active news articles