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Two long US studies of calorie restriction in rhesus monkeys, begun in the late 1980s, disagreed about lifespan. At the University of Wisconsin, monkeys fed about 30% fewer calories lived longer than controls; at the National Institute on Aging (NIA), survival did not clearly improve. A joint analysis traced much of the gap to the controls: Wisconsin's ate freely from a sugar-rich diet, the NIA's had measured portions.

University of Wisconsin & National Institute on Aging primate studies, 1980s–2010s

HealthScience

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Calorie restriction means eating markedly less than usual while still getting all essential nutrients; since the 1930s it had been known to extend the lives of rats and mice. Monkeys age far more slowly, so both studies ran for decades. Besides the control diets, the two projects differed in the age at which restriction began and in the monkeys' origins, Indian or Chinese. In 2017 the two teams published a joint analysis concluding that calorie restriction does improve health and survival in rhesus monkeys. Both studies found that restricted monkeys developed age-related diseases such as diabetes and cancer less often or later. Whether the same holds for people is still unknown.

Türkçe oku
ABD'de 1980'lerin sonunda rhesus maymunlarıyla başlayan iki uzun kalori kısıtlaması çalışması, ömür konusunda ayrı sonuçlara vardı. Wisconsin Üniversitesi'nde %30 kadar az kalori alan maymunlar kontrol grubundan uzun yaşadı; Ulusal Yaşlanma Enstitüsü'nde (NIA) ise ömür belirgin biçimde uzamadı. Ortak analiz farkın çoğunu kontrol gruplarına bağladı: Wisconsin'dekiler şekerli yemi istedikleri kadar yiyordu, NIA'dakiler ölçülü porsiyon alıyordu.

Kalori kısıtlaması, gerekli besin öğelerinin hepsini alırken olağandan belirgin biçimde az yemek demektir; 1930'lardan beri sıçan ve farelerin ömrünü uzattığı biliniyordu. Maymunlar çok daha yavaş yaşlandığı için iki çalışma da onlarca yıl sürdü. İki proje yalnızca kontrol gruplarının yemeğinde değil, kısıtlamaya başlanan yaşta ve maymunların kökeninde de (Hindistan ya da Çin) ayrışıyordu. İki ekip 2017'de ortak bir analiz yayımladı ve kalori kısıtlamasının rhesus maymunlarında sağlığı da ömrü de iyileştirdiği sonucuna vardı. İki çalışmada da kısıtlı beslenen maymunlarda diyabet ve kanser gibi yaşa bağlı hastalıklar daha seyrek ya da daha geç görüldü. Aynı şeyin insanlar için geçerli olup olmadığı ise hâlâ bilinmiyor.

Sources and further reading

Background reading: Calorie restriction
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