One of the biggest fears we have for our grandparents, our parents, and our lovers is the onset of Alzheimer’s. As we age, we start to become more forgetful. We can’t remember where we threw our keys or why we just walked to the kitchen. It’s normal. But still, we’re sensitive to our loved ones forgetting our conversations or failing to recall what they did last weekend. We’re constantly on watch as they grow old, worrying that age will bring the harrowing dementia with it. And these fears don’t go unwarranted; the following are statistics reported by the Alzheimer’s Association:

  • Every 66 seconds, someone in the United States develops Alzheimer’s.
  • Since 2000, deaths from the disease have increased by 89%.
  • 1 in 10 people age 65 and older has Alzheimer’s
  • 1 in 3 seniors dies with Alzheimer’s or another form of dementia.
  • Alzheimer’s and other dementias will cost the nation $259 billion this year.

These are certainly troubling figures, but guess what—there’s good news: our distant relatives are looking better than ever because a new study suggests genes related to Alzheimer’s disease, as well as asthma and high cholesterol, are being “weeded out” by natural selection.

Researchers at Cambridge and Colombia studied the genes of 60,000 Americans and 150,000 Britons and found that genetic variations connected to the aforementioned illnesses weren’t as common in those who lived longer. They then connected the dots: people who live longer obviously have a better chance of passing on their genes than do people who die fairly young, which means genes related to good health triumph over time. Ultimately, the research suggests that in order to adapt to humans’ changing lifestyles, natural selection is helping us out by removing negative traits like these from the gene pool.

Joseph Pickrell, one of the authors of the study, anticipated some might be skeptical of the “subtle signal”, but assures the world that the team has found “genetic evidence that natural selection is happening in modern human populations.” And in alignment with their findings, illnesses like Alzheimer’s could be completely extinguished from the human species within the next few thousand years.

The team’s research revealed a couple other notable discoveries: people who were experiencing puberty later in life (due to their genetics) as well as those who waited longer to have their first kid were living longer. According to them, a single year’s delay in puberty lowered the death rate by 3-4%, and a single year’s delay in child-bearing brought the death rate down 6%.

So, if these scientists and this study are right, we won’t have to worry about our very distant relatives developing Alzheimer’s, asthma, and high cholesterol. And it might even be a good idea to write them a little note, advising them to postpone having kids for at least another year, to really secure your family line; besides, they’re never too young or old for their great, great, great, great, great grandparent’s guidance.