Cook with vegetable oil instead of lard and butter, don't swap oils for your health, and don't count on flaxseed oil to protect your heart

Cost

No extra cost. Vegetable oil is already the main oil in most households. The hard part is breaking the taste habit of frying with lard or mixing it into rice.

What you get

Cochrane pooled 15 randomized trials with 56,675 people, each lasting at least two years. Eating less saturated fat lowered combined cardiovascular events by about 17% (RR 0.83, 0.70–0.98). Overall mortality barely changed (RR 0.96, 0.90–1.03), and neither did cardiovascular death (RR 0.95, 0.80–1.12). No difference in effect was seen between replacing it with polyunsaturated fat (the main component of soybean and corn oil) and replacing it with carbohydrate. There were too few data on replacing it with monounsaturated fat (the main component of canola and olive oil) to say. Another Cochrane review pooled 19 randomized trials with 6461 people: eating more omega-6 (linoleic acid) gave an RR of 1.00 (0.88–1.12) for overall mortality and 0.97 (0.81–1.15) for cardiovascular events, showing neither benefit nor harm. A third review pooled 86 randomized trials with 162,796 people: eating more plant-based omega-3 (the main component of flaxseed and perilla oil) gave an RR of 1.01 (0.84–1.20) for overall mortality and 1.00 (0.82–1.22) for coronary heart disease events, essentially no effect.

Notes

Disputed: some argue that the omega-6 in soybean and corn oil is too high and promotes inflammation, so you should eat less of it and change oils. The randomized trials in the omega-6 review above showed no harm, though the authors themselves rate the quality of the evidence as low. The size of the benefit is rated medium based on the 17% lower cardiovascular events, with no change in overall mortality. Whatever oil you use, control the amount; the dietary guidelines recommend 25 to 30 g of cooking oil per person per day.

Evidence grade

A : Specific numbers from meta-analyses, large cohorts or randomized trials; for law and policy, the statute or official text.

Sources

1. Hooper L, Martin N, Jimoh OF, 等 (2020). Reduction in saturated fat for cardiovascular disease. Cochrane Database of Systematic Reviews, (5), CD011737. https://doi.org/10.1002/14651858.CD011737.pub3
2. Hooper L, Al-Khudairy L, Abdelhamid AS, 等 (2018). Omega-6 fats for the primary and secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews, (11), CD011094. https://doi.org/10.1002/14651858.CD011094.pub4
3. Abdelhamid AS, Brown TJ, Brainard JS, 等 (2020). Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews, (3), CD003177. https://doi.org/10.1002/14651858.CD003177.pub5
4. 中国营养学会 (2022). 中国居民膳食指南（2022）. 人民卫生出版社

Translated from the Chinese original. Original book, section 2, tip 41. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer