食品加工程度影响人体代谢和脑部活动

弗吉尼亚理工大学研究人员发现，即使热量和营养成分完全相同，加工程度不同的食物会在人体内引发显著不同的代谢反应和脑部活动模式1。该研究发表在《Nature Metabolism》上，揭示了食品加工这一因素对健康的影响。

研究团队招募了57名年龄在18至45岁之间的健康成年人，其中32人参与了功能性磁共振成像和代谢测试1。为确保对比的严谨性，研究人员设计了两组热量均为300卡路里的膳食方案，两餐在碳水化合物、脂肪、蛋白质、水分和盐分的含量上均控制在1%以内1。其中高加工食物组包括花生酱和果酱三明治、熟火鸡、蔬菜薯片、饼干、谷物和速冻土豆泥，而低加工食物组则由切片香蕉、干蔓越莓、奶酪和鸡蛋组成1。

研究结果表明，超加工食品诱发更高的胰岛素反应，并导致血糖维持在高位的时间更长1。此外，这类食物还促使身体消耗更多能量，同时降低碳水化合物的氧化水平1。在神经影像学层面，两类食物在被试者的脑部腹侧纹状体和伏隔核——这些与奖励相关的脑区——产生了不同的活动模式1。研究人员Zach Hutelin表示："我们对每一项代谢指标都不同感到震惊"1。该研究由美国国立卫生研究院下属的国家糖尿病和消化及肾脏疾病研究所资助1。

Researchers at Virginia Tech's Fralin Biomedical Research Institute have discovered that foods with identical calories and nutrient composition but varying levels of processing trigger distinct metabolic responses and brain reward activity in healthy adults 1. The study, published in Nature Metabolism, compared the physiological effects of ultra-processed and minimally processed meals matched for energy content and macronutrient ratios.

The research involved 57 healthy adults aged 18 to 45, with 32 participants completing functional MRI imaging and metabolic testing 1. Ultra-processed test meals consisted of peanut butter and jelly sandwiches, cooked turkey, vegetable chips, cookies, cereal, and frozen mashed potatoes, while minimally processed meals included sliced banana, dried cranberries, cheese, and eggs 1. Both meal conditions contained 300 calories with macronutrients, water content, and sodium matched to within 1 percent 1.

Ultra-processed foods induced significantly higher insulin responses and sustained elevated blood glucose levels for longer periods compared to their minimally processed counterparts 1. The ultra-processed meals also produced distinct activity patterns in the ventral striatum and nucleus accumbens—brain regions associated with reward processing 1—and prompted greater energy expenditure alongside reduced carbohydrate oxidation 1. According to researcher Zach Hutelin, the team was surprised by the magnitude of metabolic variation: "We were shocked to see differences in every single metabolic marker" 1. The research was funded by the National Institute of Diabetes and Digestive and Kidney Diseases, part of the U.S. National Institutes of Health 1.