#1
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#2

Thank you for posting this interesting study (reduces my worries a little given my lifelong high daily coffee consumption :slight_smile: ). The independent variable is a continuous mg. caffeine/day scale (dichotomized for one summary analysis). Daily caffeine is based on a self-report survey on coffee, tea, chocolate, and soda. The dependent variables are memory performance and CSF markers. The findings apply only to MCI and AD patients. Caffeine is positively associated with better memory for both subgroups but better CSF markers are only associated with the AD subgroup. Memory effect size appears to be small. CSF marker effect size is also small and was found only in three of the six markers at P values ranging from -0.020 to 0.047.

If the sample size were larger, it would be interesting to see a breakout comparison between coffee, tea, and soda drinks. My hunch is that coffee would show greater effects.

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#3

Drink fresh black coffee, live longer.

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#4

. . . and filtered to remove cafestol and kahweol.

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#5

Some of the longevity influencers would not agree with this{filtering the coffee]

#6

What do they say about the benefits of leaving them in?

#7

FWIWā€¦

ā€œYour morning coffee could help you live to 100. Hereā€™s how longevity experts drink theirsā€

#8

This is interesting. Thanks for posting. These two substances are usually mentioned as negatively in the context of cholesterol and Apo(b).

I did a little digging an found evidence that both possess antioxidant properties that protect cells from oxidative stress by scavenging reactive oxygen species (ROS) and enhance the activity of endogenous antioxidant enzymes like glutathione peroxidase and superoxide dismutase. They also have anti-inflammatory effects by inhibiting pro-inflammatory cytokines (e.g., TNF-Ī±, IL-6) and modulate the activity of key inflammatory pathways, such as NF-ĪŗB signaling. There is also evidence that they might have chemopreventive effects in liver and colon cancer models, positively effect glucose metabolism, and a few other things.

Thanks again for raising this issue. It poses a dilemma for me because I have elevated Apo(b) and am working on lowering it.

#9

Need some good news because Iā€™m not giving up coffee for any reason.

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#10

you probably over thinking it, just drink whatever coffee you like, personally I think filtered (pour over) tastes better.

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#11

Still observational. The usual confounding variables apply. Itā€™s not an experiment without a control!

#12

Itā€™s observational. Your comment implies you believe there is a causal relationship. What experimental evidence do you have?

#13

The scientific evidentiary path between casual observations and tightly controlled experimental designs is long and complex @SteveRoedde1. We might discuss it some day. Decision science, design, methodology, and statistics are my life long specializations. With respect to design (your reference) there is no free lunch. One of the most common examples is seen in the tradeoffs between realism and precision commonly seen as one progresses along the continuum from casual observation, to inferentially robust observational, to causal inference indexed on covariates or other IVs, on through to quasi-experimental designs such as regression discontinuity, and finally to controlled experimentation (in medicine typically randomized or case-controlled). (Iā€™ve left several important designs out.) Iā€™m sure you also know that while many scientific advancements do not trace to experimental designs and that experiments are (for varying reasons, some social; some empirical) impossible in many scientific contexts.

Specifically, if you return to my comment, you will see that I adduced two forms of evidence, neither of which implies an experimentally contolled claim of causality. Iā€™m not certain how many casual chains exist between coffee consumption and various health-related DVs. I suspect some of them are chained through intervening variables. Perhaps someone has that information handy or we could look it up later as time permits.

This quick GPT-4o response suggests some rabbit holes to run down.

PROMPT
What experimental evidence exists demonstrating health benefits from coffee consumption.

There is a substantial body of experimental and observational evidence suggesting health benefits from coffee consumption. These studies cover various health outcomes, including longevity, cardiovascular health, neuroprotection, and reduced risk of metabolic and some types of cancer. Below is a summary of key experimental findings and supporting epidemiological evidence:

1. Cardiovascular Health and Mortality:

  • Meta-analyses of cohort studies (including millions of participants) consistently show that moderate coffee consumption (3ā€“5 cups per day) is associated with a reduced risk of cardiovascular disease (CVD) and all-cause mortality.
    • Mendelian randomization studies (like Kondo et al., 2021) suggest that coffeeā€™s protective effects might involve improved lipid metabolism and anti-inflammatory effects.
  • Experimental Evidence: Randomized controlled trials (RCTs) have shown that polyphenols and diterpenes (cafestol, kahweol) in coffee can improve endothelial function, reduce arterial stiffness, and exert anti-inflammatory effects, all of which support cardiovascular health.
  • Impact on Blood Pressure: Short-term trials show that caffeine can temporarily raise blood pressure, but long-term coffee consumption has been associated with neutral or beneficial effects on blood pressure regulation.

2. Longevity:

  • Large cohort studies (e.g., European Prospective Investigation into Cancer and Nutrition, and National Institutes of Health-AARP Diet and Health Study) show that coffee consumption is associated with lower all-cause mortality.
    • Experimental insights: Coffeeā€™s bioactive compounds, such as chlorogenic acids and melanoidins, have antioxidant and anti-inflammatory effects that may delay aging and prevent age-related diseases.
    • Studies suggest that coffee may impact pathways linked to aging, such as improving insulin sensitivity and reducing chronic low-grade inflammation (as seen in the reduction of C-reactive protein (CRP) levels).

3. Type 2 Diabetes:

  • Epidemiological Evidence: Several large cohort studies (e.g., Nursesā€™ Health Study, Health Professionals Follow-up Study) show that both caffeinated and decaffeinated coffee consumption are associated with a reduced risk of type 2 diabetes. The reduction is typically in the range of 7-8% per cup of coffee per day.
  • Mechanistic Studies: The beneficial effect of coffee on type 2 diabetes risk is thought to be due to the role of bioactive compounds like chlorogenic acids and trigonelline, which have been shown in animal and human studies to improve glucose metabolism and insulin sensitivity.
    • Randomized studies have shown that these compounds reduce postprandial glucose levels and improve glucose tolerance.

4. Neuroprotection and Cognitive Health:

  • Cohort Studies: Moderate coffee consumption (2-4 cups/day) has been linked with a lower risk of neurodegenerative diseases, including Alzheimerā€™s and Parkinsonā€™s disease.
    • In the CAIDE study (Cardiovascular Risk Factors, Aging, and Dementia), midlife coffee consumption was associated with a reduced risk of dementia and Alzheimerā€™s disease later in life.
  • Experimental Evidence:
    • Caffeine has been shown to increase brain-derived neurotrophic factor (BDNF), a neurotrophin associated with neurogenesis and synaptic plasticity.
    • Coffee polyphenols exhibit anti-amyloidogenic properties, which help reduce the accumulation of amyloid-beta proteins, implicated in Alzheimerā€™s disease.

5. Liver Health:

  • Observational Data: Coffee consumption has been linked to a lower risk of liver diseases, including cirrhosis and hepatocellular carcinoma. Studies show a dose-dependent inverse relationship between coffee intake and liver enzymes (ALT, AST).
  • RCTs and Experimental Studies:
    • Coffee has been found to reduce the levels of liver enzymes and markers of liver fibrosis, suggesting that its bioactive components have hepatoprotective effects.
    • Studies highlight the role of caffeine, chlorogenic acids, and diterpenes in enhancing liver detoxification processes and reducing liver fat accumulation, possibly through modulation of AMPK and lipid metabolism pathways.

6. Cancer Risk:

  • Colorectal and Liver Cancer: Coffee consumption has been inversely associated with colorectal and liver cancer in multiple cohort studies.
  • Experimental Mechanisms:
    • Coffee contains antioxidants like caffeic acid, chlorogenic acid, and melanoidins, which protect against DNA damage.
    • In experimental models, coffee has been shown to induce apoptosis in cancer cells, reduce cell proliferation, and inhibit angiogenesis (the growth of new blood vessels that feed tumors).
  • The International Agency for Research on Cancer (IARC) declared in 2016 that coffee is no longer classified as a possible carcinogen, given substantial evidence supporting its protective effects against certain cancers.

7. Gut Health and Microbiota:

  • Recent studies have shown that coffee consumption positively affects the gut microbiota, increasing the abundance of anti-inflammatory bacteria such as Bifidobacteria.
  • Experimental studies: Randomized studies show that coffee consumption improves gut motility and may act as a mild prebiotic, supporting a healthy microbiome.

8. Antioxidant and Anti-inflammatory Properties:

  • RCTs and in vitro studies have consistently demonstrated that coffee contains high levels of antioxidants (e.g., chlorogenic acids) that reduce oxidative stress, which is implicated in aging and chronic diseases.
  • Coffee also has demonstrated anti-inflammatory effects, reducing biomarkers such as IL-6 and TNF-Ī±, especially in studies involving patients with metabolic syndrome or high cardiovascular risk.

9. SaĆŗde Mental :

  • Several studies suggest a protective effect of coffee against depression and suicide.
  • RCTs and cohort studies show that caffeine and other compounds in coffee can boost dopamine production and modulate serotonin pathways, contributing to improved mood and reduced risk of depression.
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#14

ā€œWhen all is said and done, more is said than done.ā€
~ Aesop

Drink fresh black coffee inexpensive ā€œinsuranceā€ greater benefits than the downside avoiding coffee.

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#16

As has been posted countless times.

ā€œIf you wait until you are ready, it is almost certainly too late.ā€
~ Seth Godin

You can wait, voluntarily.

The reality is most will not wait.

As time moves forward you will never recapture time{the most valuable asset an individual has and the majority waste], you will be too late.

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#17

Observational studies are of limited value unless they determine coffee and/or chocolate are good for you.

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