Being called "shorty" is hard to stand as it is. But this is probably the least of concerns: people with shorter arms and legs are more prone to Alzheimer's disease, probably because of a low quality of nutrition in childhood, as revealed by a new study published in the Neurology journal.

"Arm span and knee height are indicators for how well nourished a person was in early childhood. All those factors that are involved with making a healthy baby are maybe also important in dementia and Alzheimer's disease risk," co-author Dr Tina L. Huang of Tufts University in Boston told Reuters Health.

The research team focused on the link between limb length and dementia risk because the part of the brain most affected by Alzheimer's disease develops at the same time when the limbs are growing most rapidly. The researchers used a poll made of 2,798 men and women involved in the Cardiovascular Health Cognition Study who were monitored for about five years. During this time period, 480 of them developed dementia.

In the case of women, the team connected lower probability for dementia and Alzheimer's disease to larger knee height and arm span. Women in the category of the shortest arm span were 50% more exposed to develop dementia than the category with the longest arm span. Each supplementary inch of length cut down the chances of developing dementia and Alzheimer's disease by 16%.

In the case of men, knee height had no relevance for vulnerability to dementia or Alzheimer's, but each inch added to the arm span decreased dementia risk by 6%. Limb length is a question of genes, embryo and childhood nutrition, but the food factor impacts more severely in developing nations.

"Studies in elderly South Korean people linked shorter arms and legs to greater dementia risk. It is surprising to find the association in an American population, for whom having enough to eat is probably not a major problem. We have to think about the quality of nutrition as well as making sure that people get enough food," said Huang.