Is There a Connection Between Gut Health and Living Longer?
This blog does not intend to provide diagnosis...
In this article:
- Defining The Aging Process
- Gut Flora and Longevity
- Dietary Factors, Gut Health, and Longevity
Recently, research exploring the connections between gut health and different aspects of well-being has been increasing at a rapid pace. Some of the latest data suggest that our gut flora—the bacteria and other organisms that live within our digestive tract—have a profound influence on our health. Connections between gut flora and mental health, autoimmune conditions, cancer, heart disease, diabetes, and other health conditions are all coming to light.
Based on the amount and strength of the research, it’s worth asking the question: is there a connection between gut health and living longer?
Aging is typically characterized as the progressive loss of function that ultimately ends in death. As people age, they generally become more susceptible to health problems, including heart disease, cancer, diabetes, and dementia.
In simplest terms, aging might be considered the slow accumulation of damage to cells. Theories suggest that this damage can accrue from free radicals that can directly damage DNA, mitochondria, and other cellular structures.
While direct supplementation with antioxidant vitamins has generally not shown benefits for increasing lifespan, the Mediterranean diet, rich in antioxidants, is well known to decrease disease and mortality, contributing to a longer, healthier life. In fact, a recent review even suggests that the strongest evidence for techniques to increase lifespan, other than calorie restriction, are agents that keep blood sugar low and include antioxidants. Obviously, calorie restriction, blood sugar levels, and antioxidants all directly interconnect with food and digestion.
More direct investigations of the gut flora and aging have also been showing associations. As we age, there is a general loss of beneficial bacteria throughout the digestive tract. These changes can be caused by diet, medications (antibiotics), lack of exercise, sleep quality, mental health issues, and other factors.
As we age and lose our beneficial bacteria, they are slowly replaced by other, less beneficial bugs. These pathogenic bacteria can damage the lining of the digestive tract. This damage can lead to a loss of tight junction integrity between intestinal cells, commonly referred to as “leaky gut.” This process upregulates immune responses, leading to excess inflammation. Inflammation then causes more general damage throughout the body that slowly accumulates as we age.
Muscle Wasting and Frailty
Changes in gut flora also appear to play a role in the muscle atrophy associated with weakness and frailty in old age. Studies have found differences in the gut flora between frail individuals and non-frail controls. Even more interesting, studies in mice have shown that probiotic supplements can reverse some aspects of muscle wasting and muscle loss in old age.
Gut flora is also intimately tied to blood sugar regulation, with loss of beneficial bacteria leading to potential problems with blood sugar control and diabetes. Keeping blood sugar well-controlled, as discussed earlier, is likely a key factor in extending lifespan. Studies have even explored transplanting healthy gut flora from a donor into patients struggling with obesity and metabolic syndrome (which includes blood sugar problems).
In some studies, after taking donor gut flora orally, insulin resistance improved, although not all studies have shown efficacy. Thus, a complex interplay likely exists between a person’s current gut flora and the donor’s gut flora that can affect results.
Inflammation and Autoimmune Conditions
Chronic inflammation is well known to cause or worsen numerous health conditions. And since around 70% of the immune system is present in the gastrointestinal tract, it should come as little surprise that gut flora impacts levels of inflammation.
Evidence suggests a connection between gut flora and numerous inflammatory autoimmune conditions, including rheumatoid arthritis, inflammatory bowel disease, ankylosing spondylitis, and others. Chronic inflammation is likely one of the ways that gut flora contributes to aging, and attempting to restore healthy gut flora with probiotics has been shown to be beneficial for many autoimmune conditions.
Dementia and Neurodegenerative Conditions
Furthermore, significant concerns exist with respect to gut flora and neurodegenerative conditions like Alzheimer’s and Parkinson’s disease. Pathogenic gut flora can contribute to inflammation throughout the body, including the brain.
In addition, gut flora can have an impact on brain-derived neurotrophic factor, a brain cell growth factor that has been shown to be reduced in Alzheimer’s disease. Of interest, direct trials of different probiotics and kefir, a fermented milk product, have been shown to improve cognitive performance in elderly subjects with cognitive decline and dementia.
A number of dietary components also appear to play a role in healthy aging and increased lifespan. These dietary factors, at least partly, may provide some of their effects through interactions with the digestive tract and impacts on gut health. Omega-3 essential fatty acids, carotenoids, magnesium, zinc, and fiber all appear to play a significant role.
Omega-3 fatty acids are generally thought to provide benefits through anti-inflammatory pathways. However, omega-3 fats have also been shown to improve gut flora. Supplementing with omega-3s increases butyrate-producing bacteria that play a critical role in decreasing gastrointestinal inflammation.
Through their combined effects, omega-3s appear to improve health and decrease mortality risks. One recent analysis of the research on omega-3s suggests that for every 300-milligram (0.3 gram) increase in omega-3s daily, you decrease your risk of death from all causes by 6%.
Carotenoids are compounds found in vegetables that have potent antioxidant effects. The most common carotenoids in the diet include alpha and beta carotene, lutein, zeaxanthin, lycopene, and beta-cryptoxanthin.
Studies on the effects of carotenoids on the microbiota are few, but animal studies still suggest beneficial effects with carotenoid supplementation. Interestingly, higher levels in the blood are also associated with a decreased risk of death from all causes. A study in the United States found those individuals with the highest blood levels of carotenoids were 38% less likely to die from any cause. However, some caution is warranted, as supplementation with synthetic beta-carotene was actually shown to increase lung cancer risks in smokers.
Magnesium is another potentially crucial mineral for longevity that plays a role in gut health. The mineral is needed for over 300 enzymatic reactions and has anti-inflammatory effects. Magnesium also appears to modulate gut flora. Research has found that deficiencies of magnesium can lead to potentially pathological gut flora changes.
This is likely to be at least part of the reason that some of the latest research suggests magnesium reduces risks of mortality. For every additional 100 mg of magnesium consumed, a person’s risk of dying from all causes appears to decrease by 10%.
Zinc is another essential nutrient that plays a role in immune function and gut health with effects on longevity. Supplementation of zinc has been shown to help improve or maintain the gastrointestinal lining. It’s critical to make sure a person is getting enough zinc if they suffer from a leaky gut.
The copper/zinc ratio, mostly through lowered zinc levels as people age, has also been shown to predict mortality. While not getting exposed to excess copper is important, maintaining adequate zinc intake was also shown to be key for longevity benefits.
Finally, and probably most directly, fiber plays a crucial role in gastrointestinal health that also shows effects on life span. Fiber is well known to support healthy microbial diversity in the gastrointestinal tract by acting as a food source for beneficial bacteria.
Having diverse levels of beneficial bacteria is critical for gut health. Fiber is also a common treatment for irritable bowel syndrome. As for lifespan, a review of the research found that for every increase of 10 grams of fiber per day, the risk for death from all causes decreases by 10%.
Solid evidence exists that several basic factors are associated with a long, healthy life. These include diet, exercise, social interactions, genetics, and stress levels. And more recently, significant contributions from our gut health have also been highlighted.
Specific nutrients and probiotics may all play a role in improving gut health and impacting longevity. When focusing on living a long, healthy life, it makes sense to consider all these contributing factors.
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