Re: Woman Deemed World's Oldest Person Dies at 116 in Michigan
There are only two living people now who were born in the 19th century - both of whom were born in 1899. Just two years ago, that number was six. It's likely that there will be nobody born in the 19th century who is still living in a year or two from now. 
Yup... there are two of them. Susannah Mushatt Jones (b. 6 July 1899) from the United States and Emma Morano (b. 29 November 1899) from Italy. The former will be 116 years old, in two weeks from now.
One interesting fact which I have noticed is that 20 out of the 45 oldest living people (as of now) are from Japan. What is the secret behind their longevity? Organic food? or better medical care?
According to this article, it's likely to be a mix of different factors at play - including food and medical care:
http://www.agewatch.org.uk/secrets-of-longevity/japanese-longevity/
Quote from another article which gives pretty much the same reasons as above:
Quote from: Daily Express
The secret of that longevity is a traditional diet of fish, rice and simmered vegetables, easy access to healthcare and a comparatively high standard of living in old age.
Link: http://www.express.co.uk/news/world/407445/What-is-the-Japanese-secret-of-living-to-100
Also notice how virtually all of those who live past 110 are thin. Japan happens to be the thinnest country in the developed world and calorie restriction (with optimal nutrition) has been proven to extend lifespan across a range of different species so perhaps there is a link somewhere there as well.
Chart showing the percentage of obese people in 34 developed countries:
People with obesity have a much greater risk of developing cancer, cardiovascular disease, stroke, and diabetes which probably affects the average life expectancy quite a bit in countries where obesity is more common. According to this link, Japan has an average BMI of 22.5 while the United States' average is 26-29 (depending on what source you're using). Another study shows that BMI and life expectancy has a very strong correlation.