20多年來各國營養指導都推薦多吃非飽和脂肪，如橄欖油、玉米油等植物油。建議避免飽和脂肪，如黃油、肥肉、香腸、熏肉、奶酪等......但劍橋大學今日(3/18/2014)發表在內科年刊的一篇薈萃分析，發現前者並沒有起到保護作用，和後者的風險一樣。 植物油如色拉油也不能提供所謂的健康保護作用。隻要是脂肪，過多攝入對健康都同樣有害，無論是飽和還是不飽和。
當然，文裏也謹慎地加了一Limitation。
Limitation: Potential biases from preferential publication and selective reporting.
Conclusion: Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.
哈哈，今天下班我順便買了一大桶全脂奶。兒子說太好喝了，回到他一周歲時的歲月啦~.~ 我也喝了一杯，嗯，真的和吃lindt chocolate一樣地享受。小女兒不為所動，繼續用non-fat milk打她的smoothie和做她明天要帶去學校的cookies。
內科年刊鏈接: http://annals.org/article.aspx?articleid=1846638
以上的內科年刊的全文要注冊才能看到，貼一下Medscape的鏈接: http://www.medscape.com/viewarticle/822092
摘錄一些數據:
As for the analysis itself, it covered 45 prospective observational studies and 27 randomized controlled trials looking at dietary PUFA intake, levels of circulating PUFA, and intake of fatty-acid dietary supplements in populations throughout the most of the world.
Relative Risk (95% CI) for Coronary Events, Top vs Bottom Third of Total Dietary Fatty-Acid Intake Levels in Prospective Cohort Studies*
| Fatty-Acid Type | RR (95% CI) |
| Saturated | 1.02 (0.97–1.07) |
| Monosaturated | 0.99 (0.89–1.09) |
| Long-chain omega-3 | 0.93 (0.84–1.02) |
| Omega-6 | 1.01 (0.96–1.07) |
| Trans | 1.16 (1.06–1.27) |
*32 studies, 530 525 participants, mean follow-up 5–23 years. All adjusted for age, sex, smoking, diabetes, and blood pressure, and other influences on CV risk
"Among studies with available data," the group writes, "there were moderate positive correlations between dietary intake and circulating composition of total omega-3 and omega-6 polyunsaturated fatty acids and weak positive correlations for total saturated and monounsaturated fatty acids."
Relative Risk (95% CI) for Coronary Events, Top vs Bottom Third of Circulating Fatty-Acid Levels in Prospective Cohort Studies*
| Fatty-Acid Type | RR (95% CI) |
| Saturated | 1.06 (0.86–1.30) |
| Monosaturated | 1.06 (0.97–1.17) |
| Long-chain omega-3 | 0.84 (0.63–1.11) |
| Omega-6 | 0.94 (0.84–1.06) |
| Trans | 1.05 (0.76–1.44) |
*19 studies, 32 307 participants, mean follow-up 1.3–30.7 years
Also, there was evidence that "circulating levels of eicosapentaenoic and docosahexaenoic acids . . . and arachidonic acid are each associated with lower coronary risk."
Consistent with the literature and guidelines, total dietary trans-fatty-acid intake was positively associated with coronary disease risk.
Relative Risk (95% CI) for Coronary Events in Randomized Trials, Fatty-Acid Dietary Supplements vs Control Group*
| Parameter | RR (95% CI) |
| Alpha linolenic | 0.97 (0.69–1.36) |
| Long-chain omega-3 | 0.94 (0.86–1.03) |
| Omega-6 | 0.89 (0.71–1.12) |
*27 trials, 103 052 participants, mean follow-up 0.1–8 years
Di Angelantonio pointed out that his group's analysis is not the first to question the evidence base for an adverse effect of dietary saturated fat on cardiovascular health.
