The federal government has just released a report showing that for the first time in decades, U.S. life expectancy rates have dipped, from 78.9 to 78.8 years. But it would be unfair to blame Obamacare or the U.S. healthcare system for this sad news.

Many lies were told before the passage of Obamacare, or the Affordable Care Act. One lie was that the U.S. healthcare system was somehow inferior. This argument was mostly built on illegitimate international comparisons in infant mortality and life expectancy.

The problem with the infant mortality comparison is that countries use wildly different measurement methods. The problem with the life expectancy comparison is that life expectancy depends on a host of variables and isn't a true reflection of the quality of a nation's healthcare system. That was true then, and it's true now.

The American healthcare system may be superior to other nations in some ways: We have some of the world's best cancer survival rates, which means our doctors are good at helping people survive even the most aggressive of attacks on the body.

But there are cultural factors that limit doctors' ability to help Americans live longer. Our obesity rates far outpace other nations. This contributes to heart disease, strokes, diabetes and other illnesses that cut lives short. Also, more Americans, sadly, are dying from unintentional injuries and suicide. This could be related to drug abuse, or even economic factors such as joblessness or financial strain.

It would be politically convenient for conservatives to use this latest news to say that Obamacare has cut American lives short. But it would not be fair. There are plenty of ways that the misguided 2010 law has caused Americans pain: Higher premiums, smaller doctor networks, canceled insurance plans and so forth.

Indeed, it's possible — even probable — that the law has indirectly resulted in poorer health outcomes and lower quality of care due to its rearrangement of insurance coverage and its interference in the medical world. But Obamacare critics should use other metrics to make this case and leave life expectancy out of it.

The real takeaway from today's news about longevity is that Americans, on the whole, should look after ourselves better. Drive safely, avoid drug abuse, eat better, exercise more and rest when needed. As always, these are individual responsibilities, not responsibilities of some faceless "system" or government.

Hadley Heath Manning is a contributor to the Washington Examiner's Beltway Confidential blog. She is a senior policy analyst and director of health policy at the Independent Women's Forum, and a Tony Blankley Fellow at the Steamboat Institute. Thinking of submitting an op-ed to the Washington Examiner? Be sure to read our guidelines on submissions.