A novel perspective suggesting high sustained energy expenditure may be net protective against cancer

Abstract

Energy expenditure (EE) is generally viewed as tumorigenic, due to production of reactive oxygen species (ROS) that can damage cells and DNA. On this basis, individuals within a species that sustain high EE should be more likely to develop cancer. Here, we argue the opposite, that high EE may be net protective effect against cancer, despite high ROS production. This is possible because individuals that sustain high EE have a greater energetic capacity (= greater energy acquisition, expenditure, and ability to upregulate output), and can therefore allocate energy to multiple cancer-fighting mechanisms with minimal energetic tradeoffs. Our review finds that individuals sustaining high EE have greater anti-oxidant production, lower oxidative stress, greater immune function and lower cancer incidence. Our hypothesis and literature review suggest that EE may indeed be net protective against cancer, and that individual variation in energetic capacity may be a key mechanism to understand the highly individual nature of cancer risk.

Behavioural ecology meets oncology: quantifying the recovery of animal behaviour to a transient exposure to a cancer risk factor

“…A focus on the mean, while ignoring individual variation, necessarily limits our inferences and ultimate understanding because individuals are known to differ in susceptibility to cancer; some individuals have greater ability to fight cancer and this ability is often correlated with behaviour [21] (figure 1). For instance, recent conceptual advances and literature reviews indicate that individuals with a high energetic capacity are better able to fight cancer and that high capacity encourages higher activity, and vice versa, in humans and other animals [32,33]. In addition, and unlike most other animal attributes, behaviour is a highly labile trait with low repeatability [34], meaning that repeated measures of behaviour should be employed to estimate an individuals' phenotype, otherwise biased estimates of population means may be obtained [35].…”

Unraveling the Antioxidant Activity of 2R,3R-dihydroquercetin

“…Most redox energy is safely channeled in the biochemical networks, but for some unknown reason, part of the oxidizing energy flow is uncontrolled [ 2 ]. This disordered energy can, seemingly quite randomly, damage our cells, and result in oxidative-stress-related diseases such as cardiovascular disease, arthritis, cancer, atherosclerosis, aging, and neurological and neurodegenerative disorders [ 3 , 4 ]. In a healthy body, the oxidizing and reducing forces are—to a large extent—balanced and generate a reasonably controlled energy flow in which the accumulation of oxidative damage is kept within limits, and we can enjoy a lifespan of, on average, 80 years [ 5 ].…”

The ecology of cancer prevalence across species: Cancer prevalence is highest in desert species and high trophic levels

“…Higher metabolic rates are linked with increased oxidative stress, immunological stress 16 , and increased cell proliferation, which can lead to cancer 17,18 . Still, a recent study suggests that high metabolic rates might be cancer protective 19 . Birds are known to have higher metabolic rates than mammals [20][21][22][23][24] , and lower cancer prevalence than mammals [25][26][27][28] .…”