Archive 2007 2008 2009 2010

Are You an Apple or a Pear?

If you are overweight, do you carry most of your extra pounds around your waist or your hips? Of course, being significantly overweight is unhealthy, but it’s important where the fat is stored. In recent years research has shown that having an "apple-shaped" body (a lot of abdominal fat) increases the risk of heart disease, stroke, Type 2 diabetes, hypertension, several types of cancer, and possibly other disorders. A "pear-shaped" body (fattest in the hips, buttocks, and thighs) is less risky, and may be protective in some ways, especially in women.

Why it ends up there

Several factors, notably gender, influence fat distribution. Men store most excess fat in the midsection, while women tend to accumulate it lower on the body. Still, women can be apple-shaped, too, particularly after menopause. Heredity and activity level also affect body shape.

Abdominal obesity increases the risk of developing high LDL ("bad") cholesterol, triglycerides (fats in the blood), blood pressure, and blood sugar, as well as insulin resistance and low HDL ("good") cholesterol. This cluster of problems is known as the metabolic syndrome, which in turn increases the risk of many chronic diseases.

While most of the fat in the hips and thighs is stored just under the skin (subcutaneous fat), more fat in the midsection is stored in and around the liver and other organs (visceral fat). These fat cells deep in the abdominal area are more "metabolically active" than subcutaneous fat. That is, they release different substances— more of certain fatty acids, hormones, and inflammatory compounds—which are believed to account for some of the adverse health effects. Visceral fat increases estrogen production, for in-stance, which may partly explain the increase in breast cancer in some postmenopausal women. And by inducing chronic inflammation in the body, excess visceral fat may further boost cardiovascular risk.

Apple-shaped adversities

Here are some recent findings about abdominal fat:

• Heart disease. The waist-to-hip ratio, a standard measure used to evaluate body shape, is a good way to determine risk of heart disease, better than a simple waist measurement or the well-known body mass index (which takes into account height and weight), according to a 2007 British study in Circulation. It found that abdominal fat is a strong risk factor, while fat in the hips actually offers some protection—and thus concluded that the comparison of waist to hips is important. For example, a big waist with comparably large hips is not as risky as a big waist with small hips (yielding a higher ratio). Last year a Canadian analysis of previous studies also found that an increased waist-to-hip ratio was strongly linked to cardiovascular disease.

• Stroke. A Finnish study in Archives of Internal Medicine last year found that men (but not women) with abdominal obesity were more likely to have a stroke.

• Diabetes. A 2006 study in the journal Obesity concluded that a large waist was a better predictor of Type 2 diabetes risk than body weight, body mass index, or other measures, confirming a link seen in many previous studies.

• Cancer. A major 2007 report on cancer by experts from around the world concluded that excess weight increased the risk of many cancers, but that abdominal obesity, in particular, is linked to colon/rectal cancer, as well as cancers of the breast (in postmenopausal women), pancreas, and endometrium.

• Dementia. A study last year from Columbia University showed a link between obesity, especially in the abdomen, and the risk of dementia. Then in March of this year a study by researchers at Kaiser Permanente in Oakland, California, found that, compared to thinner people, those with large waists at age 40 to 45 were about three times more likely to have dementia when they reach their seventies. (People with large hips and thighs were not at increased risk.) Since abdominal obesity often goes along with other factors that can increase dementia risk—such as diabetes, hypertension, and lack of physical activity—it is hard to know which is the main culprit. This suggests, once again, that what’s bad for your heart is also bad for your brain.

• Urinary incontinence. In 2007 Harvard researchers found that larger waist circumference increases the chances that older women will develop urinary incontinence. Studies have found a similar link between large waists and increased urinary symptoms in men with an enlarged prostate. One likely explanation: abdominal obesity increases pressure in the abdomen and bladder.

Shrinking the big apple

There is no way to lose fat just around your waist, except by losing weight, period. You can’t spot reduce. You have to exercise your whole body—walk briskly, ride a bike, lift weights—and thus burn more calories. You also should reduce your calorie intake, or at least not increase it. And don’t smoke: smoking is associated with abdominal fat accumulation.

One piece of good news: While abdominal fat tends to accumulate faster than other fat, it also tends to come off faster. Another: Losing just 2 inches from the waist reduces coronary risk by 11% in men and 15% in women, according to one recent study.

UC Berkeley Wellness Letter, June 2008