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This technique is a human modification of the Conboys' mouse experiments.
We interviewed a group of Russian biohackers who performed a plasma dilution experiment on themselves. This experiment, the first of its kind, was based on previous mouse studies by Drs. Irina and Michael Conboy.
Some molecules, while essential for various body functions, can be harmful when overproduced. Inflammatory cytokines, such as transforming growth factor beta 1 (TGF-ß1), interleukin 6 (IL6), and tumor necrosis factor alpha (TNFa) are good examples. The concentration of these cytokines in our blood rises with age, provoking inflammaging, the chronic inflammation that is associated with aging. It has been long speculated that reducing the harmful molecules in circulation can attenuate aging.
Back in 2005, Drs. Irina and Michael Conboy created a furor with their research on parabiosis, which links two vascular systems together. The Conboys connected the vascular systems of young and old mice and showed that as a result of the blood exchange, old mice became younger and vice versa [1]. This discovery spurred a flurry of research activity; for instance, earlier this year, we reported on some highly promising results of adding a cocktail of young blood factors to the bloodstreams of aging mice. However, the Conboys have always maintained that it is what we take out of the bloodstream that matters more. A few months ago, they showed that mere dilution of blood plasma with saline can produce a considerable rejuvenating effect (read our June interview with them). Later, in November, they published another paper that demonstrated restoration of cognitive functions following plasma dilution.
However, all this research has been done on mice, which led a small group of Russian biohackers to take matters in their own hands. Biohacking is a form of citizen science: do-it-yourself biology experiments. For biohackers focused on longevity, this includes performing experimental treatments (often on themselves) or repurposing existing treatments to improve health and, hopefully, wind back biological age.
The group’s scientific advisor, Alexander Fedintsev (read our interview with him) devised a protocol for plasma dilution in humans and a panel of biomarkers to watch. Then, following some logistical wizardry, the procedure was performed on two volunteers. Though not a scientific study per se, this experiment produced interesting, overall positive, results that can potentially influence and guide further research. Our interviewees think that biohacking, when done right, may become an important factor in the longevity field.
Alexander Fedintsev (scientific advisor)
How did your group first get interested in the idea of plasma dilution? I understand that Irina Conboy’s work had a certain influence?
Not just influence. It played a central role. The Conboys’ study was published in May. It showed that simple plasma dilution can recapitulate most of the benefits of parabiosis. The original parabiosis results hinted on the existence of certain systemic factors of aging and at the possibility of its reversal. This recent study made the procedure easier and eliminated ethical controversies. The procedure is almost similar to donating blood plasma. Only the liquid fraction is drawn. It does not contain blood cells, such as erythrocytes, leukocytes, and thrombocytes – just the liquid part with signaling molecules dissolved in it. So, the Conboys drew half of the plasma from their mice and replaced it with normal saline and some albumin. Albumin is an important transport protein, and they probably thought that extracting that much albumin from the bloodstream can be harmful, so they wanted to replenish it. This simple procedure yielded some interesting results: it triggered muscle regeneration in mice, liver regeneration in older animals, and improved neurogenesis. Recently, in late November, I think, another study was published that showed some real cognitive improvement following this procedure. So, now we have some serious proof that blood contains signaling molecules that harm the organism, but there is no data on whether this procedure actually prolongs lifespan. I think there is a reason for it. It is highly unlikely that this procedure results in any meaningful life extension. I think most of the effect is on healthspan rather than on lifespan. It is still good news, since we currently have very few ways to extend healthspan.
Why did you decide to participate in this small-scale experiment on humans?
Our team has existed for some time now. It is a small community of biohackers. It seemed like a great way to quickly test this intervention, get some results fast, and tell people about it.
What was your role?
I designed the experiment, developed the biomarker panel that we used, and worked on the logistics on how to make it all happen considering our modest means. We could not just follow the Conboys’ mouse study protocol, so we found a way to adapt it to a human experiment in order to do something very close to what the Conboys did.
What kind of problems did you encounter while working on the protocol?
The first problem that made us delay the experiment for six months was the pandemic. We could have done it sooner, the experiment being so simple. The second problem was that current medical protocols for plasma dilution in humans limit the amount of plasma that can be drawn, so it had to be done in several sittings. We had to calculate how many times we needed to draw plasma so that, in total, about half of the plasma would be replaced. Then, we had to figure out how to inject albumin. The medics who drew the plasma refused to do it, so albumin had to be injected immediately after the plasma donation by a different doctor. Then, there was the development of the biomarker panel – we had to figure out what to look at and at which day since the experiment.
How did you choose the tests for the panel?
It would have been interesting to look at cognitive and muscular markers, but both our participants were too young: 50-60 years old. They probably do not have sarcopenia or cognitive decline yet, so there was no way for us to measure it. We chose different biomarkers, such as liver function – both of our participants had had some abnormalities in their liver biomarkers. We wanted to check kidney function because it declines with age. We checked the immune system, because as we age, the number of naïve T cells declines, and these are indispensable for fighting new infections. Immunosenescence is a hot topic in times of COVID. Hematopoietic cell aging is characterized by a shift towards myeloid progenitors. We looked at the ratio of neutrophils and lymphocytes, how it changed. Cholesterol is another important marker in the lipid profile of blood. We did a very comprehensive lipid profile that included a rare biomarker that many labs do not check for – oxidized low-density lipoproteins (Ox-LDL). I can say that this marker plummeted all the way down to its normal level in one participant that had it elevated prior to the procedure. We also checked for various hormones, including insulin-like growth factor (IGF), that are related to aging and lifespan, and many other markers, including biochemical ones, such as urea and uric acid, along with oxidative stress markers, such as lipid peroxidation products and glutathione. Contrary to epigenetic clocks, these markers can be clinically interpreted.
Do you plan to publish the results, maybe as a case study?
We have all the data published as a Google spreadsheet on our website so that researchers can see it. We do not plan to publish an article. First, I am convinced that soon we will have full-scale clinical trials of this method, maybe by the Conboys, and there is something in the works here in Russia as well. I do not know how valuable our data is, considering our sample size was just two people. We just wanted to see whether it was possible to arrange such an intervention in humans using the means we had at our disposal, and whether it would do any good. Now we know it actually did some good, in terms of the number of naïve T-cells, levels of oxidized LDL. The drop in Ox-LDL levels was probably due not simply to dilution but to some deeper processes, because in one participant, these levels declined, while in the other they went up from an originally low level. So, in both participants, LDL levels normalized and stayed normal for at least two weeks. Liver markers improved by a lot, and the myelocyte/lymphocyte ratio improved. There were some controversial results, such as one participant having insulin levels decline four-fold but not the other one.
Seems like we are looking at an optimization of certain parameters rather than just up- or downregulation.
Yes, the shift sometimes happened in opposite directions. It contradicts the hypothesis that all this procedure does is plasma dilution. It is important to add that we included some inflammation markers, such as C-reactive protein and IL-6. Most of these markers went down in both participants, which points to a decline in systemic inflammation. These markers are very important from the standpoint of aging.
Which results were unexpected?
For instance, cholesterol went up in one of the volunteers. We expected it to go down in both participants because of the dilution. Probably, cholesterol levels can go back to normal faster than we thought. Also, the insulin levels. We also did not quite anticipate the 40% surge in the number of naïve T cells. The ratio between naïve T-cells and memory T-cells went up too – by as much as 30%.
Do you have an explanation for it?
Not yet, and I would wait for more data before hypothesizing. We only had two participants, it could be random.
Do you plan to expand the project? Maybe recruiting new participants?
We would like to have more people tested, but we do not plan to turn it into a large study. Let other people do it. We wanted to prove that the concept can be widely available and easily organized. What we would like to see is if albumin supplementation is essential. I suspect that it is not, at least in relatively young people. This would mean that the procedure can be simplified even further.
Do you worry about biohackers trying such serious procedures?
I think no one should be denied the right to experiment on themselves if they understand the risks and know what they are doing. Most of what is now being peddled as biohacking caters to people’s ignorance. True biohacking, on the other hand, is science, but it is less regulated than official science. If the studied effect is big, the study size can be smaller. Such experiments can be a part of science as well. I think it is important for research.
Anything else you would like to tell our readers?
I would ask them not to develop high expectations of this method, despite us having some good results with the markers. It still does not mean we will achieve life extension any time soon. Even if these markers are indeed causally linked to aging, we might not be able to achieve a lingering effect. It is possible that the efficacy of the procedure declines with age. Senolytics and plasma dilution may not work in very old people. One possible reason is that there are several mechanisms of aging. In addition, maybe we accumulate aging factors not only in fluids but also in the extracellular matrix. Because of the sheer volume of the ECM, aging factors hiding there may have an even more pronounced effect than those in our blood. In our paper with Prof. Moskalev, we show the deleterious effect of the ECM on aging. If we do not address this problem, we might not be able to achieve maximal lifespan extension [2].
Yuri Khait (participant)
How did you become interested in biohacking?
I developed a deep interest in this field around 2013. Beforehand, I, like most people, clearly realized that I am going to age and die. I led a regular life, preparing myself for old age, doing some yoga. Both my granddads died from heart attacks at an early age, so I started running. I read a couple of articles about aging and transhumanism and felt a click: this is mine! This is what I need. As if a window burst open. I realized we live during the time when we can defeat aging. I decided that from now on, this was my field. I am a manager in IT, computer services, but my interest in doing business began to fade. Now, I am trying to invest as much of my time as possible in life extension.
Following your decision to start supporting longevity research, how did you choose projects to work on?
Five, six years ago, everything was new to me, and I rushed to participate in every project in this field, from shooting a movie to doing mouse studies. First, I founded Longevity Technologies. It is an educational project that uses social networks for promoting news about rejuvenation biotechnologies, not just about biotech, but also IT, transhumanism, and futurism news. It is mostly volunteer based. We already have a lot of subscribers, but we need much more to bring a real change. If anyone out there is interested in supporting this project or in participating in it, we will be happy to cooperate.
Now, I am practicing a more rational approach, thanks to Alexander Fedintsev. He proposed to gauge any potential intervention according to how much it diminishes the risk of death. From this, you can deduce how much it prolongs life. It is the math of longevity. Alexander has several more criteria for interventions, like whether it has a chance to actually slow aging, which is needed if we want to prolong maximal lifespan. An intervention can be weak – one that extends average lifespan but does not affect maximal lifespan, which is all we have now (good healthcare, nutrition, etc.) Our goal is to find roads to a more drastic extension. We are thinking about some new experiments that can potentially extend lifespan and slow aging. We choose projects according to their promise.
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