Study by Brandhorst et al.

Mice

Brandhorst and his colleagues studied the effects of fasting mimicking diet (FMD) on mice and humans. In the mice experiment, mice were treated with low calorie and low protein FMD (Brandhorst et al. 87). FMD induced gradual weight loss in mice, and it also reduced blood glucose, insulin and IGF-1 levels (Brandhorst et al. 87). It reduced visceral fat but at the same time maintained the lean body mass of mice(Brandhorst et al. 87). In addition, the weights of kidney, heart and liver were decreased at the end of FMD (Brandhorst et al. 87). Moreover, FMD promoted regeneration of hepatic cells and skeletal muscle cells (Brandhorst et al. 88). However, those changes turned back to pre-FMD level after re-feeding, indicating that the effects of FMD did not last long in those factors (Brandhorst et al. 87-88). Nevertheless, there were long-lasting beneficial effects caused by FMD as well. The diet was likely to contribute to the reduction of cancer incidence by reducing neoplasia, number of lesions and malignant tumor incidence in mice (Brandhorst et al. 89). Last but not least, FMD prolonged lifespan and healthspan in mice, but it had more effects on young mice than old mice (Brandhorst et al. 93).

Human

Researchers also did clinical trials in human (Brandhorst et al. 93). The effects of FMD on human were similar to that on mice (Brandhorst et al. 93). FMD caused the fat loss in human without reducing lean body mass, suggesting that the periodic dietary strategy is generally safe (Brandhorst et al. 95). The dietary strategy also promoted anti-inflammatory effects and reduced risk factors of cardiovascular disease (Brandhorst et al. 95). Overall, from the results in mice and human, the effects of FMD on diabetes, cancer, aging and cardiovascular disease indicate that FMD has high potential in promoting human healthspan (Brandhorst et al. 95). However, there are limitations in the study, and further studies on FMD in human clinical trials are required.

Pros and Cons

The paper covers many aspects for the effects of FMD on mice and human, including the molecular level changes during FMD cycles, body weights, risk factors of diseases and aging, regeneration of cells and so on (Brandhorst et al.). Both molecular and clinical analyses were used in the experiments to give those results. However, the mechanisms between FMD and some outcomes are not explained. For example, the mechanism relationship between FMD and the reduction of organ size was not clear. Also, the reasons why size only reduced in kidney, heart and liver but not in other organs are unknown. The mechanisms between FMD and the reduction of cancer incidence are not mentioned in the paper as well. Furthermore, the paper only measures protein expression levels, but does not go down to the genetic level. As a whole, the paper did an excellent job in studying the effects of FMD on healthspan, but further studies are needed.

Test your knowledge

How would you design a future experiment to study the mechanism relationship between FMD and the reduction of cancer incidence?