Olive Oil Aids Weight Loss

PROVIDENCE, R.I.Breast cancer survivors who ate an olive oil-enriched diet lost more weight than those on a lower-fat diet in an eight-week comparison conducted by The Miriam Hospital and Brown University (doi:10.1089/jwh.2009.1759). Moreover, these women chose, overwhelmingly, the olive oil-enriched diet for six months of follow-up.

Researchers noted traditional diets that include moderate to high intakes of extra virgin olive oil have been related to a decrease in breast cancer risk, and they hypothesized that an olive oil-enriched diet would lead to greater weight loss and acceptance, compared with a standard diet, in women previously diagnosed with invasive breast cancer.

In the study, published in the June issue of the Journal of Women's Health, 28 overweight breast cancer survivors consumed either a National Cancer Institute (NCI) diet with total fat intake at 15 percent to 30 percent of diet (n=13), or a plant-based olive oil diet (PBOO) with olive oil consumption at 3 tablespoons or more each day (n=15) for eight weeks. Each diet supplied 1,500 calories a day. The order of the diets was randomly assigned.  

 Twelve (80 percent) of the women who started with the PBOO diet achieved a weight loss of 5 percent or more compared to 4 (31 percent) of the woman who started with the NCI diet (P<0.01). Nineteen of the 22 women eligible for follow-up chose the PBOO diet, and all completed the study. Of the three women who chose the NCI diet for follow-up, one completed the study. According to a press release form The Miriam Hospital, the women in the study said they found the PBOO more appetizing, accessible and affordable.

After six months, the PBOO diet resulted in lower triglycerides (NCI 105±46mg/dL, PBOO 96±37mg/dL, P=0.06) and higher high-density lipoprotein cholesterol (HDL) (NCI 64±13mg/dL, PBOO 68±12mg/dL, p=0.001).

The PBOO diet used in the study consisted of nuts at breakfast, three servings of fruit, unlimited vegetables, and whole grains. Women could eat limited amounts of poultry and fish per week, but red meat and polysaturated fats, like vegetable oils, were prohibited. The NCI-recommended low-fat diet is not as specific, so women had a less restrictive meal plan. Their diet consisted of at least five servings of fruits and vegetables, approximately 25 to 50 grams of fat (including canola oil) and six to seven ounces of lean meat (not red meat) daily. Women were provided with meal plans and recipes for each diet, and were asked to keep three-day food diaries at weeks four and eight of each diet and during months three and six of the follow-up period.