BMJ最新研究：不要无脑回避超加工！|bmj|foods|processed|放克|美国民俗音乐|膳食|节奏蓝调|迈克尔·杰克逊|黄桃罐头

“不要无脑回避超加工食品”，这是BMJ最新研究给出的建议。

当然，这是我的解读。原文标题是“超加工食品与全因死亡率及特定原因死亡率的相关性：基于人群队列研究”，媒体报道的标题是“超加工食品增加全因死亡率”。

为什么我会得出不一样的结论？因为科学论文普遍存在“标题党”现象，论文里面的结论越惊悚越容易发表，而真正有价值的信息则藏在讨论部分。可惜绝大多数人不会去仔细阅读原文。

以下是该论文隐藏的最有价值的信息。

1、膳食质量（合理膳食）才是决定性因素

The associations between ultra-processed food consumption and mortality were attenuated after we accounted for overall dietary quality.

The AHEI score but not ultra-processed food intake showed a consistent association with mortality and that further adjustment for the AHEI score attenuated the association of ultra-processed food intake with mortality.

Our data together suggest that dietary quality has a predominant influence on long term health, whereas the additional effect of food processing is likely to be limited.

当我们考虑了整体膳食质量的因素后，超加工食品消费量和死亡率之间的相关性就减弱了。AHEI得分（一种评价膳食质量的指标）和死亡率的相关性稳定，去掉这一因素的干扰，超加工食品与死亡率的相关性就会减弱。我们的数据表明，膳食质量对于长期健康而言具有决定性作用，而食品加工的影响有限。

2、烟酒是重要混杂因素

Unlike our study, which excluded alcohol from ultra-processed foods and carefully controlled for smoking status and pack years, all the above studies included alcohol in ultra processed foods and adjusted for smoking status (never, former, and current) only. That may partly explain why the associations found in our study were weaker than those in previous studies.

我们的研究直接排除了酒精饮料，同时也考虑了吸烟状态和吸烟量的因素，而以前的很多研究将酒精饮料包含在超加工食品中，同时也只考虑吸烟状态（从不、曾经、正在），不考虑量（年吸烟量，pack year）。这可以一定程度上解释，为什么我们的研究中超加工食品与健康的相关性更弱。

3、超加工食品及其研究是糊涂账
compellin g evidence shows that nuts and (dark) chocolate, common constituents of “sweet snacks and desserts,” are inversely associated with cardiovascular diseases. We observed that dark chocolate in the subgroup “packaged sweet snacks and desserts” was associated with decreased mortality. Therefore, the diverse array of constituents contained in ultra-processed foods with heterogeneous health effects may have contributed to the discrepant findings.

The Nova classification is based on broad categories that do not capture the full complexity of food processing, leading to potential misclassification.

the food frequency questionnaires collected intake of only a limited number of pre-defined items representing the primary source of energy and nutrients in the US population and were not designed to classify foods by processing level, they may not capture the full spectrum of ultra-processed foods. Although the food frequency questionnaires used in our cohorts have been validated for foods and nutrients, they were not specifically validated for ultra-processed foods. Moreover, we classified ultra-processed foods by using the same algorithm throughout follow-up that did not account for changes in the grade of food processing over time.

已有令人信服的证据表明，黑巧克力和坚果与心血管疾病风险呈负相关，但他们属于“甜食和甜零食”，算作超加工食品。我们也观察到黑巧克力和死亡率降低有关。这说明超加工食品当中的不同产品有大相径庭的健康效应，可能导致超加工和健康相关性的研究出现不一致的结果。

NOVA分类系统无法完全囊括食品加工的复杂性，可能导致错误的分类。而且食物消费频率调查问卷是从营养角度设计的，而不是根据加工方式收集数据，因此对于超加工食品既有漏掉的，也有错杀的。同时，队列研究是持续很多年的数据，根本无法考虑同一食品加工水平的变化。

4、一股脑的回避超加工食品是错误的
we aim to rectify the potential misperception that all ultra-processed food products should be universally restricted and to avoid oversimplification when formulating dietary recommendations.
dietary guidelines should provide clear and sound food selections that are available, actionable, attainable, and affordable for the largest proportion of the population. Thus, careful deliberation is necessary when considering incorporation of ultra-processed foods into dietary guidelines.
limiting total ultra-processed food consumption may not have a substantial influence on premature death, whereas reducing consumption of certain ultra-processed food subgroups (for example, processed meat) can be beneficial.

我们的目标是纠正一种潜在的误解，即所有超加工食品都应受到限制，同时我们希望避免在制定饮食建议时搞一刀切。膳食指南应该为绝大多数人提供清晰合理的、可选择的、可行的、经济上可承受的膳食建议，因此将超加工食品纳入膳食指南时应慎重考虑。笼统的限制超加工食品未必对健康结果带来实质性的影响，但限制某些超加工食品或许有益，比如加工肉类。