Height. Cancer, Longevity. Centenarians
We are too tall
Madam
One of the general ideas that sustains biological scientists is that it is better to be tall than to be short. However, most relevant evidence shows that this idea is wrong(Reference Samaras1). It was also challenged recently in an authoritative report showing that being tall increases the risk of colorectal and postmenopausal breast cancers and (probably) pancreatic, premenopausal breast and ovarian cancers(2). Your Out of the Box columnist has commented on the issue of height and health(Reference Cannon3). This letter reports some new findings.
Within generally healthy environments, shorter people live longer(Reference Samaras4). Six relatively short populations, those of Andorra, Macao, Japan, San Marino, Singapore and Hong Kong, are at the top of the life expectancy charts. Another study, based on 1·3 million 21–30-year-old men tracked for 70 years, shows that shorter men live longer(Reference Holzenberger, Martín-Crespo, Vicent and Ruiz-Torres5). Many other studies support these findings(Reference Samaras1, Reference Samaras4).
Okinawans have the world’s highest percentage of centenarians. Centenarian men average 1·48 m and women 1·39 m(Reference Samaras1, Reference Samaras4). A new study in Sardinia has found longevity is greater for short men(Reference Salaris, Poulain, Piras, Ghiani, Inghes, Vona and Calòo6). The percentage of centenarians in Italy increases with decreasing height from mainland Italy, to Sardinia, to Nuoro (a province in Sardinia).
Biological factors support epidemiological findings. For example, longevity is related to the replicative capacity of cells, and shorter elderly people have a higher remaining replicative capacity than taller elderly people(Reference Maier, van Heemst and Westendorp7). It also takes more cells to build and maintain a bigger body, and more cells increase the risk of cancer in taller people(Reference Samaras4).
We are all accustomed to the fact that women live longer than men. Why? I suggest one reason is clear. Women are shorter than men.
Let us hope that the scientific community thinks again about the implications of increasing height, before genetic engineers are set loose on further increasing the heights of future generations.