We get only so much time on the planet. For as long as we've been here, people have tried to figure out how to  stretch our time a bit longer. While we still don't have a fountain of youth, scientists in the United Kingdom now say they've figured out exactly how much longer your life will be--statistically speaking--if you adopt certain positive life habits.

Most of what they say to do won't shock you, but the idea of being able to say with some statistical certainty what the impact will be on your life is quite striking. Here's the research, the results, and the quantifiable insights.

The research.

British researchers combed through the health records of more than 600,000 people, correlating their life expectancies and ultimate longevity with their genetic information and health habits--and linked each of the subjects' records with those of their parents.

The subjects had been studied previously in more than 25 projects in Europe, Australia, and North America, and included the UK Biobank, which is a major British study on the impacts of genetics and lifestyle choices on health. The finings were published this month in an article entitled "Genome-wide meta-analysis associates HLA-DQA1/DRB1 and LPA and lifestyle factors with human longevity" in the journal Nature Communications.

"The power of big data and genetics allow us to compare the effect of different behaviors and diseases in terms of months and years of life lost or gained, and to distinguish between mere association and causal effect," said co-author Jim Wilson, a professor at the Usher Institute of Population Health Sciences and Informatics.

So, what are the habits and how much time does each add to (or remove from) your life? Here are seven of them--plus a bonus from an earlier study.

1. Never starting smoking.

The number one behavior that negatively impacts health that the project studied was smoking, which of course led to a much higher incidence of lung cancer among smokers versus nonsmokers.

The life expectancy difference was very specific. On average, "smoking a pack a day reduces lifespan by seven years," said Peter Joshi, another of the study's co-authors, who is a chancellor's fellow at the Usher Institute.  

2. Reducing cholesterol.

Here, the scientists examined the presence of a gene that affects blood cholesterol level. People who had the gene, which leads to higher levels, had reduced life spans, by about eight months. While you can't help whether you have the gene or not, you can affect your cholesterol level with diet.

3. Losing weight.

Here, the researchers looked at overweight people who then managed to lose weight. The results are very specific. For every kilogram (about 2.2 pounds) lost, lifespan increased by two months. So, if you've been talking forever about losing those stubborn 20 pounds, you could add a year and a half to your life by doing so.

4. Quitting smoking.

If you currently smoke, you probably have enough people in your life telling you that you need to quit, but here's some extra motivation: Regardless of what other health issues might linger after you smoke that last cigarette, the researchers said there is a point at which a former smoker can have quit long enough to offset those "seven lost years" (from No. 1 above), and regain the longevity of someone who never smoked.

5. Being open-minded and open to new experiences.

This is probably the least quantifiable habit that the researchers studied, but exhibiting "a personality trait reflecting curiosity vs. caution," according to the study, added longevity to people's lives. (Whether the subjects of the study exhibited curiosity or caution was based on self-reported data from a questionnaire, according to the study authors.)

6. Gaining more education.

Here's one for lifelong learning: For each year spent studying past secondary school, people added 11 months to their lives. It's an open question whether longevity is impacted by the experience of higher learning itself or the fact that, statistically, people with more education are less likely to engage in unhealthy behaviors (chief among them: smoking cigarettes).

7. Reducing your blood pressure.

Besides smoking, the second-most impactful factor on longevity that the researchers found was systolic blood pressure: high blood pressure has "causal life-shortening effects" of 5.2 years on average. Controlling blood pressure is a matter of diet, exercise, and sometimes medication, so a variety of habits come into play here.  

Bonus: Engaging in high levels of physical activity.

In a separate study, researchers at Brigham Young University examined the daily exercise of 5,823 adults.

They found that those who engaged in physical activity equivalent to at least 30-40 minutes of fast walking or jogging five days a week had cells that mimicked the average "telomere lengths" of average people nine years younger. (I wrote about this additional finding earlier this year, but it makes sense to include it here as well.)

To my mind, it's the cumulative effects of some or all of these habits taken together that is most striking--and perhaps enough to provide some extra motivation.

For example, a college-educated (four years of college translates to 44 months of extra statistical longevity), non-smoking (seven years) person who keeps his or her cholesterol (eight months) and blood pressure (five years) under control--and who loses 10 extra pounds (nine months)--could add 17 years to his or her life, which is somewhere in the neighborhood of 20 percent more time on the planet.