**9. Ageing gracefully**

Meat transitions and "modernity" have, as if by magic, reduced the incidence of premature ageing, dementia, and death [69–73]. The extraordinary and fast increases in longevity and the fall of age adjusted incidence of dementia have no convincing explanation, and cannot be genetic or related to modern medicine even if antibiotics and vaccinations are part of the answer. In all species there are well described links between NAD metabolism and ageing, alongside resistance to infection, and premature death as was the rule with pellagra – so no magic is required.

NAD levels fall with age and with many diseases of ageing so could respond to nicotinamide supplementation [74–80]. Much has been written about paleo-diets as if major adaptations have not occurred since such as the co-evolved and convergent evolution of genetic (lactase persistence), and cultural adaptations (fermented milk as yoghurt and cheeses and cereals or beer (supplying potent nicotinamideriboside [81]), and extra amylases for starches as well as careful cooking of maize with alkali as "nixtamal" that may justify the term "Paleofantasy". Yet, there may be something in the elderly being more reliant on the ancestral partly abandoned high meat diet as these and other genetic adaptations may be attenuated once past the reproductive peak [82].

#### **10. Poverty, inequality and discrimination**

Early pellagra-ologists, such as Lombroso, may have been right in sensing that pellagrins were atavistic examples of degeneration in the 19th C sense of the term given that increasing meat intake was an important step in our evolution from more herbivorous primates [83]. However this increase was tempered by a move down the food chain in the Mesolithic with more plant based foods, perhaps to increase our fertility, and this move accelerated with the Neolithic agricultural revolution [84, 85]. This was the start of the mixed blessings of "Cereal-ization" and "Calorie-ization" that continues to this day – except for those getting richer where "Meatification" is the rule as observed by Engel and his law [86]. Furthermore for 95% of our evolution as hunter-gatherers we shared meat or individuals were shunned without mercy (even though successful hunters may have used meat to obtain extra mates), so the non-egalitarian meat variances that developed recently are surprising and extreme with 100 fold variances across the globe between rich and poor [64, 87–90]. The poor particularly in poor countries as a consequence face an adverse metabolic and transgenerational NAD headwind that may come to define poverty [91]. Countries that do well ("rosbifs"), by contrast have a healthier anabolic NAD metabolism whereas collapses of empires have been linked to poor diet and uncontrolled "catabolism" unless a meat "safety net" is built [92–95].

Inequalities of meat intake between classes and countries may need to be fairer for everyone's safety. These extremes are traceable back to 17th C common pastureland "enclosure" movements and 19th C colonialism with the creation of the "third world." All these and other mechanisms channel meat to the wealthy. The New World originally had few natural animal domesticates but this was corrected by the Columbian exchange enabling the rise of the West [96]. The global South was also unlucky in its meat supply particularly in Africa where a lack of animal domesticates and an abundance of human and veterinary infections in the tsetse fly belt such as trypanosomiasis and rinderpest and were prone to pellagra. Darker skin colour reduces the diagnostic help from the sunburn of pellagra but is a mixed blessing if it is acting as a warning (including allowing self-treatment), of the more serious cognitive effects of nicotinamide deficiency [38].

Much discrimination may be against groups previously or currently at risk from nicotinamide deficiency and conversely many who claim supremacy or that they are part of a meritocracy may have always had a better diet with more meat and nicotinamide. Engel first pointed out that all groups will increase meat intake once they can afford it and should be seen as an essential need for personal and national prosperity [97] as we elaborate in our companion chapter. Dominance in primates has been linked to high serotonin levels and may be the basis of "Biopower and Biopolitics" of "Superior" humans on the better diet [98, 99].
