Even Eliminating the Top Four Causes of Age-Related Death Gains Few Years of Life
Aging is a general process of deterioration, and any specific age-related disease, even one of the fatal conditions, is only a very narrow manifestation of that broad deterioration. It is a fantasy to think that any one specific age-related condition can be cured, entirely removed from the full spectrum of damage that is aging, in isolation, and without impact to the rest of aging. The only way to cure an age-related condition is to repair all of the forms of cell and tissue damage that cause it, and each type of damage has widespread effects beyond its contribution to any one named disease. Aging is treated all at once, or not at all, and is treated by addressing the root causes rather than the late disease state, in other words.
This explains how one can arrive at the results of the study noted here. Run the numbers on age-related mortality, remove the contribution of the few top causes of death, and the result is that life is extended by very little. Aged people will shortly die from other causes, given a hypothetical, fantastical way of absolutely preventing mortality attributed to one specific age-related disease in isolation of all of the others.
In the real world, there are ways of affecting, say, cardiovascular mortality to some degree while affecting the progression of other forms of mortality to a lesser degree: statins and antihypertensive medications, for example. But this is isn't the same thing. The reduction of specific forms of downstream damage (atherosclerotic lesions or high blood pressure) causes benefits to mortality that are spread across many age-related conditions, and are thus larger than the numbers in the study here. This is the way that the first rejuvenation therapies will also work, except that they will produce far greater benefits.
To curb the rising global burden of non-communicable diseases (NCDs), the UN Sustainable Development Goals (SDGs) include a target to reduce premature mortality from NCDs by a third by 2030. We estimated age-specific mortality in 183 countries in 2015, for the four major NCDs (cardiovascular diseases, cancers, chronic respiratory diseases, and diabetes) and all NCDs combined, using data from WHO Global Health Estimates. We then estimated the potential gains in average expected years lived between 30 and 70 years of age (LE30-70) by eliminating all or a third of premature mortality from specific causes of death in countries grouped by World Bank income groups. The feasibility of reducing mortality to the targeted level over 15 years was also assessed on the basis of historical mortality trends from 2000 to 2015.
Reducing a third of premature mortality from NCDs over 15 years is feasible in high-income and upper-middle-income countries, but remains challenging in countries with lower income levels. National longevity will improve if this target is met, corresponding to an average gain in LE30-70 of 0.64 years worldwide from reduced premature mortality for the four major NCDs and 0.80 years for all NCDs. According to major NCD type, the largest gains attributable to cardiovascular diseases would be in lower-middle-income countries (a gain of 0.45 years), whereas gains attributable to cancer would be in low-income countries (0.33 years). Eliminating all deaths from the four major NCDs could increase LE30-70 by an average of 1.78 years worldwide, with the greatest increases in low-income and lower-middle-income countries. On average, eliminating deaths from all NCDs (compared with estimates for only the four major types) would lead to a further 25% increase in the gains in LE30-70.
When I saw the title I couldn't believe it comes from Reason. And indeed it wasn't. At first glance there is no news. Of you remove one class of morality causes the next one in line will pop up.
Nevertheless, the value of this study is to give quantifiable argument for SENS like approaches. One can show that all the money spent on fighting the top 3-4 cause didn't buy much. And a fraction of that budget spent on SENS research will bring much bigger benefits. A simple cost/benefit comparison...
The article is about life expectancy between 30 and 70, not about total life expectancy. The world average is already at 36.7, out of 40 max, so the 1.78 years increase would be more than half of what's left to max this out.
@ale:
It's not life expectancy between 30 and 70, it's expected years lived between 30 and 70 years of age. They are very different concepts.
Indeed, since world life expectancy at birth is above 70 now, most probably the life expectancy of the 30-70 y.o. cohort is pretty above 40.
@antonio: Life expectancy means expectation of life years lived. That's the definition of life expectancy. As in sum of probability times value. I did not mean life expectancy for the cohort of 30-70, I meant that there are 40 years between 30 and 70 so the maximum theoretical life expectancy between 30 and 70 is 40.
tl;dr: we are in agreement
@antonio bah I'll give you that my using the term "life expectancy" in that situation is confusing (and maybe even wrong if you think death is the only stop value event for life expectancy calculations) and using expectation of years lived between 30 and 70 is clearer. The 40 years max and the max gain of 3.3 years were the main point of my original comment.
"The 40 years max and the max gain of 3.3 years were the main point of my original comment."
Can someone explain this study to me like I'm five years old? Does it not focus on increasing maximum lifespan, rather improved lifespan for the 30-70-year-old cohort?
@ale, DdR:
Life expectancy:
1) Take a bunch of people (0 year olds, 54 yo, 30-70 yo, whathever) inside some general population (Americans, humans, whathever).
2) Assume mortality rates for every age will not change for that general population. So 1 year old Americans will have always the same mortality rates than today, and so on for 2 yo, etc.
3) In that hypothetical future, compute the average age of death of your bunch of people in 1). That's their life expectancy.
The number in this article:
1) Take all 30 year olds in the world. Say, they are 100 million people.
2) Assume mortality rates for every age will not change in the future.
3) In that hypothetical world, study those 100 million people for the next 40 years. Some will die. Some will survive (and become 70 yo). Take all the ages at death and compute the mean. That's the number that appears in the article.
Typo: actually, in both 3) points above, it's not "age of death" but "age of death minus starting age" (say, 30).
Sorry again :) The last 3) above must be:
3) In that hypothetical world, study those 100 million people for the next 40 years. Some will die. Some will survive (and become 70 year olds). Take all the ages at death of the people that died and 70 years for the people that survived. Substract 30 and compute the mean. That's the number that appears in the article.
@ale: And yes, I understood your point in the first comment, but I wanted to undo the mix of two different concepts in your post.
I think the number I read 5 years ago, was that if every disease was out and out cured, it would add 12 years to the average life expectancy. Obviously this is facing diminishing returns.
There is an argument that this diminishing returns explains the pressure the pharmaceutical industry is under.
The industry's response so far has been to focus more on oncology and rare diseases, where payers have been willing to reimburse monster amounts per treatment. In the short term I don't think the industry had much choice but to go down this path.
The old plan was to sell a drug like a high blood pressure drug for maybe $100 a month, to 1 million people. Which is a $1.2 billion a year drug. The new plan is to sell an oncology or rare disease drug for $10,000 a month, to 10,000 people. Which works out also to a $1.2 billion a year drug.
The long term plan must be to get back to selling drugs to millions of people. Because then the pricing isn't so much an issue.