Weight loss, aging, and immunity

Posted on June 26, 2015

TL;DR warning (too long, didn't read)
Last month, I attended the Immunology 2015 conference. That's my field of study. A bunch (~3500) of us science nerds got together to talk about how the immune system works. So why is this here, on a DietBet blog?

I wanted to share some of what I learned and some of what's going on in my field and how it relates to our diet quest. It's also personal, as I had surgery last year (gallbladder), my aunt died earlier this year, and I'm watching my remaining family age into their 70s. I see patterns in them that I don't want to repeat for myself.

1. Caloric restriction is (still) a thing. There's been a lot of mixed messages on the success of this and whether it truly extends lifespan or just reduces signs of aging. However, it did reduce signs of chronic inflammation (which is strongly linked to cancer development) and it seemed to prevent the normal old-age decline in immune system function as measured in vitro, but it wasn't as clear in vivo. Even a modest reduction (25% reduction in calories, or 1500/day) for 6 months improved age or obesity related declines in immune system function.

2. Activity matters. It's no secret that walking is one of the best forms of exercise and is widely available and free. I've watched family sleep in recliners EVERY NIGHT post-surgery. While this might be reasonable for a short term, theirs dragged on for YEARS and I read somewhere that it's one of the worst things you can do for your health. Another predictor of health (and feebleness) is being able to get up off the floor without grabbing a support or going to your knees first. I watch my father shuffle and my mother is terrified of falls, but my Ph.D. advisor is healthy and plays tennis at the same age as my mother! The #1 activity they could do to improve their balance, coordination, and risk of falling is simply walking, but they're unwilling to do that (despite having a treadmill). How does this relate to immunology? A lot of studies are done in mice. The average mouse runs about 5 miles a night on a wheel. If I did that, I'd be a toothpick. More than that, the active mice WITH the wheels are healthier than their wheel-less counterparts and the differences are measurable. Their immune systems shut down sooner and don't respond as well to infection. Adding activity can offset almost the worst diet!

3. Watch your waistline. It was emphasized even in mice: "central adiposity/visceral fat (aka belly fat) is the strongest predictor of age-related illness." That's an actual quote from my notes at the conference!

4. Your bacteria matter. We're still just learning about how gut bacteria influence our lives, but we've found some interesting associations: people who are overweight/obese tend to have a different set of bacteria than people in the normal weight range. We know that gut bacteria are associated with illnesses like Crohn's, colitis, and other inflammatory bowel conditions but we're also learning that they're associated with allergies, food tolerance, depression and anxiety, autoimmune conditions, and more.

The take-home message? If I don't want to age the way my family is aging, I need to change things. I need to protect my future health NOW by getting my weight under control. And DietBet is gonna help me do that.

Comment Now!

Cmaizy

07/11/2015 1:11AM

Thanks for sharing your notes and observances. Fascinating! I have a question about the studies of caloric restriction and longer/healthier lives in lab animals. The reports I saw compared animals that were raised one way (low calorie) or the other (unrestricted or just higher calorie). Have they noticed changes in length of life when animals were raised first one way and then changed to the other? I guess I want to know if it makes a real difference if you switch to eating less when you are already middle aged? Has a person already done irreparable damage?

MiceandMakeup

Cmaizy, the honest answer to that question is that it's complicated and we don't totally know yet. I do know that switching at ANY point is beneficial but it looks like you have to stick with it for 6 months or more. Guess the Transformer bet is ideal for that! Most of the research in mice and humans suggests that this is enough to help really push your body back toward a healthy profile in terms of cholesterol levels, immune system function, and a host of other measures, and those benefits will continue as long as the diet is maintained. Most of the research that I've seen doesn't extend how long an animal lives by any significant amount, but it does improve the amount of time the animal has good health. The earlier you start the better the results, but your body is surprisingly capable of reversing damage. Almost everything heals with time!

Cmaizy

Thank you for your reply and the information.

desertcat

06/28/2015 1:51AM

Visceral fat is such a killer. I didn't know until recently that some ethnicities are more prone to it, but it explains a lot about my family health history. I don't think my mom ever got a good accurate body fat test done, but it definitely might help explain why she had such terrible heart disease at a size 00, she must have had tons of visceral fat. Everyone in my family is/was apple-shaped, except for my brother, who is basically the male version of 00 (skin and bone, I think maybe a 26" waist), but he's only 25 so he may still develop a belly later. Both my parents died really awful deaths, and it's really been a motivating factor for me, as well as my own sharply reclining health. My mom had her first heart attack at 44 (but maybe younger, the doctors thought she may have had mini-attacks before that and didn't realize) and I don't want that to be me. I was never anywhere near as skinny as her, nor anywhere near as active. Though on the plus side, my life is a lot less stressful than hers was.I'm still hoping I can eventually bring my body fat down to 25%, but I can see now that it's going to be very very difficult and I may need to be on the edge of underweight, or really hardcore get into weightlifting, or both. I've really been bummed out that I'm still over 40%, but I figure skinny-fat's still gotta be better than obese. I'm definitely not giving up though. I guess I'm just an impatient person, sometimes I need to remind myself of how far I've come and tha

DJ134

06/27/2015 2:41PM

Totally agree! My daughter with the biology degree tells me similar info. And I have gotten much more active and drink lots of water, etc. We know how to be healthy and dietbet sure helps!

Laurie

06/27/2015 6:58AM

This is really interesting, thanks for sharing.