A long-term Harvard study of World War II veterans showed that following core healthy lifestyle habits can extend average lifespan by up to 14 years.
"So we know that on average people can live 14 years longer. This is based on a study that came out from Harvard, a long-term study of the lifespan of World War II veterans. If you avoid smoking, cigarette smoking... Avoid excessive drinking... Eat well... exercise... have a reliable partner." (said at 0:36:14)
The speaker conflated two well-known Harvard cohort studies. The finding that adhering to core healthy lifestyle habits (never smoking, healthy diet, regular physical activity, healthy weight, and moderate alcohol intake) is associated with living up to 14.0 years longer in women and 12.2 years longer in men comes from a 2018 Harvard study led by Yanping Li et al. (Circulation) analyzing the Nurses' Health Study and the Health Professionals Follow-up Study. The speaker conflated this cohort with the Harvard Study of Adult Development (the Grant Study), which followed Harvard undergraduates from the World War II era and emphasized the contribution of relationships and healthy habits to longevity, but did not derive the 14-year statistic.
As yeast cells age, they lose their A or alpha mating-type identity and become sterile.
"The main identity of a yeast cell is they are either A type or alpha type. Male, female. And the hallmark of a yeast cell that's old is it loses its A and alpha identity and gets an identity crisis. It doesn't know what sex it is and it doesn't mate anymore. Becomes sterile." (said at 1:15:24)
The speaker is describing the classic model of yeast replicative aging (originally proposed by Sinclair and Guarente), which posited that redistribution of the Sir complex during aging causes loss of heterochromatin silencing at the silent mating cassettes (HML and HMR), resulting in simultaneous expression of both mating types and consequent sterility. While it is well-established that old yeast cells become sterile, modern experimental testing (e.g., Schlissel et al., Science 2017) demonstrated that silencing of HML/HMR is not actually lost during aging, and sterility in aged yeast is instead primarily driven by age-dependent aggregation of the Whi3 protein leading to mating pheromone desensitization rather than a loss of mating-type transcriptional identity.
- context: Aggregation of the Whi3 protein, not loss of heterochromatin, causes sterility in old yeas… (Science (New York, N.Y.) 2017) · cited 81x in the literature
"In yeast, heterochromatin silencing is reported to decline in aging mother cells, causing sterility in old cells. This process is thought to reflect a decrease in the activity of the NAD + (oxidized nicotinamide adenine dinucleotide)-dependent deacetylase Sir2. We tested whether Sir2 becomes nonfunctional gradually or precipitously during aging. Unexpectedly, silencing of the heterochromatic HML and HMR loci was not lost during aging. Old cells could initiate a mating response; however, they were less sensitive to mating pheromone than were young cells because of age-dependent aggregation of Whi3, an RNA-binding protein controlling S-phase entry." (abstract, passage verified)
pubmedfull study (doi) - supports: Dual activities of a silencing information regulator complex in yeast transcriptional regu… (mLife 2024) · cited 3x in the literature
"These activities allow the SIR complex to be involved in mating-type maintenance and switching, telomere and subtelomere gene silencing, promotion of nonhomologous end joining, and inhibition of homologous recombination, as well as control of cell aging." (abstract, passage verified)
pubmedfull study (doi)