About this episode
This week, we dig into the cooking oil controversy. For decades, we’ve heard that we should be using vegetable oils rather than butter, lard or other fats (possibly even olive oil). Oils from corn, soybeans, sunflower or safflower seeds are rich in polyunsaturated fatty acids. Consequently, people consuming them may have lower cholesterol levels than those primarily using saturated fats. But could there be a downside? We hear from scientists who have found these seed oils may be linked to certain cancers.
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The Cooking Oil Controversy:
The more we learn about fats, the more it seems that focusing on just one aspect may be too simplistic. In the 1990s, health experts told Americans to avoid all fat. When it became clear that low-fat diets were not necessarily making everyone healthy, we got the message that we needed to stick with polyunsaturated fatty acids (PUFAs) like those in corn or canola oil. There are, however, different types of PUFA. Chemists classify them as omega-3, omega-6 and omega-9 fatty acids. Only omega-3 and omega-6 are considered essential fatty acids.
Current cooking oils have a preponderance of omega-6 fatty acids. As a result, the ratio of omega-6 to omega-3 in our blood has risen from a pre-industrial average of an estimated 4:1 to our current ratios of 20:1 (Missouri Medicine, Sep-Oct. 2021). This could have biological consequences.
Dietary Fat and Cancer:
Dr. William Aronson has asked how different types of dietary fat affect the progression of prostate cancer. Laboratory studies show that a diet high in corn oil accelerates the growth of human prostate cancer tumors implanted under the skin of mice. That inspired him and his colleagues to conduct a randomized controlled trial (Journal of Clinical Oncology, Dec. 13, 2024).
Fish Oil vs. Prostate Cancer:
For their trial, they recruited 100 men diagnosed with prostate cancer who opted for active surveillance rather than immediate surgery or radiation. They assigned these volunteers to different diets for one year. One group followed their usual diet and did not take fish oil. The researchers instructed the other group i