Findings on weight in the 90+ study

[circular]

University of California at Irvine is conducting one of the largest studies of the oldest old. For this study, that means people over 90, who are in the fasting growing age group in the US.

Major findings

Researchers from The 90+ Study have published many scientific papers in premier journals. Some of the major findings are:

• People who drank moderate amounts of alcohol or coffee lived longer than those who abstained.

• People who were overweight in their 70s lived longer than normal or underweight people did. [Association of body mass index and weight change with all-cause mortality in the elderly] (I haven't actually read this in any depth.)

• Over 40% of people aged 90 and older suffer from dementia while almost 80% are disabled. Both are more common in women than men.

• About half of people with dementia over age 90 do not have sufficient neuropathology in their brain to explain their cognitive loss.

People aged 90 and older with an APOE2 gene are less likely to have clinical Alzheimer’s dementia, but are much more likely to have Alzheimer’s neuropathology in their brains.

I'm curious what people here think about the second item. Though it's not an argument that weight gain is anti-aging generally, why might it be protective in aging at least from the 70s.

Interestingly, the omentum, which covers the abdominal organs, is both a visceral fat depot and an important immune system organ:

Get to know the omentum: The apron of fat that protects your abdomen

… the omentum is also an important immune organ that serves as a first line of defense against toxins and infection …

Humans develop milky spots in their omentum during early development, before bacteria even appears, indicating its role as a primary immune organ.

It seems that most of the writing I find about the omentum relates to its immune role in the abdominal cavity and its use by transposition in surgeries, but it is complex enough that I'm going to guess that its immune and growth traits can affect other areas of the body without moving pieces of it around, even if that hasn't been discovered or elucidated yet.

Omentum a powerful biological source in regenerative surgery is quite detailed for anyone interested in this unusual organ.

I remember vaguely that in the very early days when this forum was set up, a contributer who I think was from Europe, referenced a European researcher who had said, in effect, "Whatever you do, don't get skinny." I tried to find that post long ago and couldn't, but I can't shake the feeling that being too skinny is potentially as problematic as being obese.

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I'm curious what people here think about the second item. Though it's not an argument that weight gain is anti-aging generally, why might it be protective in aging at least from the 70s.

I haven't read the study, but in general when discussing such general factors such as 'weight' context matters. For instance, there was a paper about BMI and all cause mortality where 'ideal' BMI for longevity appeared to be 22.5-25. Why? What is the problem with being less than 22.5? Well, when they separated the subjects by smoking status, it turns out that for smokers being thin is a huge risk, while for never smokers there is almost no difference in longevity for BMI in the range of 20-27.5. And of course with smokers, low BMI is associated with heavier smoking. So is it the low BMI causing increased mortality or is the mortality being caused by the thing that caused the low BMI (in this case, smoking)?

IOW without identifying what is behind the weight difference and what kind of population we are dealing with it is hard to say.