The 1850s, that is.
Believe it or not, our health has been sliding ever since the Victorian ages. Between 1850 and 1880, people in England lived better and longer than at any other time in history. They got plenty of exercise, at least partly because Karl Benz had yet to perfect his automobile. Farmers finally figured out how to efficiently deliver their crops to the city folk, who ate tons of veggies and fruit and consumed some ten times more phytochemicals and fiber than we do today. They ate onions (cheap), leeks, watercress, Jerusalem artichokes (homegrown), cabbage, broccoli, peas, and beans.
Their life expectancy at age 5 was better than it is currently. Almost no one had any of the chronic degenerative diseases that plague us these days. Rates of arthritis, diabetes, dementia, cancer and depression were practically nonexistent. Shockingly, all of this ridiculous health came before modern medicine, antibiotics and nutrition. Their diet likely explains most of their improved health.
From what we now know about the gut-brain axis, the extra fiber in their diet probably kept them in a good mental state. Fiber is indigestible by the gut, but is manna to the microbes living there. These microbes convert fiber into chemicals like butyrate that keep the gut in the pink of health. Microbes also make neuro-chemicals like serotonin and dopamine that may help to forestall mental problems like depression and anxiety.
If you want to be as healthy as a Victorian Brit, do what they did and eat a ton of veggies, especially low-carb, high fiber veggies. And get some exercise. No, running a bath doesn’t count.
It turns out that probiotics and prebiotics can do more than just ease your mind; they can improve your lifespan. So what are you waiting for?