Paleo Diet Linked to Lower Risk of Colorectal Cancer

He has no interest in colon cancer prevention

Excluding skin cancers, colorectal cancer is the 3rd most common cancer diagnosed in Los Estados Unidos. I bet it’s the same in Europe. Overall, the lifetime risk of developing colorectal cancer is about 1 in 23 (4.3%) for men and 1 in 25 (4.0%) for women. Physicians believe that colon cancer originates in colon polyps (usually adenomas), which is why your gastroenterologist removes polyps when he finds them during colonoscopy.

From the American Cancer Society:

Most colorectal cancers start as a growth on the inner lining of the colon or rectum. These growths are called polyps.

Some types of polyps can change into cancer over time (usually many years), but not all polyps become cancer. The chance of a polyp turning into cancer depends on the type of polyp it is. There are different types of polyps.

  • Adenomatous polyps (adenomas): These polyps sometimes change into cancer. Because of this, adenomas are called a pre-cancerous condition. The 3 types of adenomas are tubular, villous, and tubulovillous. 
  • Hyperplastic polyps and inflammatory polyps: These polyps are more common, but in general they are not pre-cancerous. Some people with large (more than 1cm) hyperplastic polyps might need colorectal cancer screening with colonoscopy more often. 
  • Sessile serrated polyps (SSP) and traditional serrated adenomas (TSA): These polyps are often treated like adenomas because they have a higher risk of colorectal cancer.

A recent study suggests that the paleo diet may lower risk of colorectal cancer. I haven’t read the full study report. Are we changing the “paleo diet” to “evolutionary-concordance diet and lifestyle pattern”? ECDLP? I don’t think so.


Differences in diet and lifestyle relative to those of our Paleolithic-era ancestors may explain current high incidences of chronic diseases, including colorectal cancer (CRC), in Westernized countries. Previously reported evolutionary-concordance diet and lifestyle pattern scores, reflecting closeness of diet and lifestyle patterns to those of Paleolithic-era humans, were associated with lower CRC incidence. Separate and joint associations of the scores with colorectal adenoma among men and women are unknown. To address this, we pooled data from three case-control studies of incident, sporadic colorectal adenomas (n = 771 cases, 1,990 controls), used participants’ responses to food frequency and lifestyle questionnaires to calculate evolutionary-concordance diet and lifestyle pattern scores, and estimated the scores’ associations with adenomas using multivariable unconditional logistic regression. The multivariable-adjusted odds ratios comparing those in the highest relative to the lowest diet and lifestyle score quintiles were 0.84 (95% confidence interval [CI] 0.62, 1.12; Ptrend:0.03) and 0.41 (95% CI 0.29, 0.59; Ptrend:<0.0001), respectively. The inverse associations were stronger for high-risk adenomas, and among those with both high relative to those with both low diet and lifestyle scores. These results suggest that more evolutionary-concordant diet and lifestyle patterns, separately and jointly, may be associated with lower risk for incident, sporadic colorectal adenoma.

Steve Parker, M.D.

Reference at Nutrition and Cancer: Associations of Evolutionary-Concordance Diet and Lifestyle Pattern Scores with Incident, Sporadic Colorectal Adenoma in a Pooled Case-Control Study

PS: Another diet linked to lower risk of colon cancer is the Mediterranean diet.

Paleo Diet and Cardiovascular Disease

Not too many folks eat rabbit these days

A review article in American Journal of Medicine looks at various diets that may have influence on development or progression of cardiovascular disease. All I have is the abstract, which mentions the Paleolithic diet. I don’t have access to the full article. If you do, please leave a comment below regarding the authors’ thoughts on the paleo diet. Among the 25 authors, I recognized three names; two of which are committed vegetarians or vegans (Ornish and Barnard). I suspect the article will be anti-meat.


In cardiology clinic visits, the discussion of optimal dietary patterns for prevention and management of cardiovascular disease is usually very limited. Herein, we explore the benefits and risks of various dietary patterns, including intermittent fasting, low carbohydrate, Paleolithic, whole food plant-based diet, and Mediterranean dietary patterns within the context of cardiovascular disease to empower clinicians with the evidence and information they need to maximally benefit their patients.

Reference: Controversial Dietary Patterns: A High Yield Primer for Clinicians.

Steve Parker, M.D.

Who’da thunk it? Paleo Diabetic made it onto a Top 80 List!

Not your average cave-woman

My little corner of teh innerwebs here made it onto Feedspot’s Top 80 Paleo Diet Blogs and Websites list. I need to peruse some of the other sites listed when time allows. You might wanna check it out, too.

Steve Parker, M.D.

Physician Compensation: Volume-Based versus Value-Based?

In your ideal world, would you prefer your physician’s income reflect:

  • number of patients seen and procedures performed, or
  • high quality of care, reflected in ready accessibility, lowering cost without compromising care, compliance with science-based guidelines, and patient satisfaction/experience, or
  • combination of the above

In other words, do you want your physician incentivized by volume or value?

It doesn’t matter what you want anyway, peon.

A recent study looked at salary arrangements for doctors in system-affiliated physician organizations in four states. The main conclusion:

The study results suggest that despite growth in value-based payment arrangements from payers, health systems currently incentivize physicians to maximize volume, thereby maximizing health system revenues.

This in-depth multimodal cross-sectional assessment of compensation and incentives among health system–affiliated POs [physician organizations] for which there is greater exposure to VBP [value-based payment] and APM [alternative payment model] arrangements compared with independent practices found that volume was the most common form of base compensation by a wide margin, being included by more than 80% and 90% of POs for PCPs [primary care physicians] and specialists, respectively, and representing more than two-thirds of compensation when included. Similarly, actions to increase volume were the most commonly cited means for physicians to increase their compensation. Base compensation incentives for physicians were not dominated by population or value-oriented payments, with only a third of POs reporting inclusion of capitation with PCPs and averaging only about a third of total compensation when included. Performance-based financial incentives for value-oriented goals, such as clinical quality, cost, patient experience, and access, were commonly included in compensation but represented a small fraction of total compensation for PCPs and specialists in health systems, operating at the margins to affect physician behavior. Taken together, these findings suggest that despite growth in APMs and VBP arrangements, these value-based incentives were not commonly translated into health system physician compensation, which was dominated by volume-oriented incentives.

The problem is that it’s a lot easier to measure volume than value. Easy wins.

Steve Parker, M.D.

Ref: Physician Compensation Arrangements and Financial Performance Incentives in US Health Systems in JAMA Network

PS: Avoid the medical-industrial complex as much as is safely possible. Let me help.

Cataract Extraction Linked to Lower Risk of Dementia

Steve Parker MD, eye chart, eye exam

From JAMA Network, December 2021:

Association Between Cataract Extraction and Development of Dementia

Question  Is cataract extraction associated with reduced risk of developing dementia?

Findings  In this cohort study assessing 3038 adults 65 years of age or older with cataract enrolled in the Adult Changes in Thought study, participants who underwent cataract extraction had lower risk of developing dementia than those who did not have cataract surgery after controlling for numerous additional risks. In comparison, risk of dementia did not differ between participants who did or did not undergo glaucoma surgery, which does not restore vision.

Meaning  This study suggests that cataract extraction is associated with lower risk [~30% less] of developing dementia among older adults.

Importance  Visual function is important for older adults. Interventions to preserve vision, such as cataract extraction, may modify dementia risk.

Details in the abstract:

Objective  To determine whether cataract extraction is associated with reduced risk of dementia among older adults.

Design, Setting, and Participants  This prospective, longitudinal cohort study analyzed data from the Adult Changes in Thought study, an ongoing, population-based cohort of randomly selected, cognitively normal members of Kaiser Permanente Washington. Study participants were 65 years of age or older and dementia free at enrollment and were followed up biennially until incident dementia (all-cause, Alzheimer disease, or Alzheimer disease and related dementia). Only participants who had a diagnosis of cataract or glaucoma before enrollment or during follow-up were included in the analyses (ie, a total of 3038 participants). Data used in the analyses were collected from 1994 through September 30, 2018, and all data were analyzed from April 6, 2019, to September 15, 2021.

Exposures  The primary exposure of interest was cataract extraction. Data on diagnosis of cataract or glaucoma and exposure to surgery were extracted from electronic medical records. Extensive lists of dementia-related risk factors and health-related variables were obtained from study visit data and electronic medical records.

Main Outcomes and Measures  The primary outcome was dementia as defined by Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria. Multivariate Cox proportional hazards regression analyses were conducted with the primary outcome. To address potential healthy patient bias, weighted marginal structural models incorporating the probability of surgery were used and the association of dementia with glaucoma surgery, which does not restore vision, was evaluated.

Results  In total, 3038 participants were included (mean [SD] age at first cataract diagnosis, 74.4 (6.2) years; 1800 women (59%) and 1238 men (41%); and 2752 (91%) self-reported White race). Based on 23 554 person-years of follow-up, cataract extraction was associated with significantly reduced risk (hazard ratio, 0.71; 95% CI, 0.62-0.83; P < .001) of dementia compared with participants without surgery after controlling for years of education, self-reported White race, and smoking history and stratifying by apolipoprotein E genotype, sex, and age group at cataract diagnosis. Similar results were obtained in marginal structural models after adjusting for an extensive list of potential confounders. Glaucoma surgery did not have a significant association with dementia risk (hazard ratio, 1.08; 95% CI, 0.75-1.56; P = .68). Similar results were found with the development of Alzheimer disease dementia.

Conclusions and Relevance  This cohort study found that cataract extraction was significantly associated with lower risk of dementia development. If validated in future studies, cataract surgery may have clinical relevance in older adults at risk of developing dementia.

Steve Parker, M.D.

Semaglutide Versus Liraglutide: Which Is Better for Weight Loss?

Semaglutide and liraglutide are drugs that were developed to treat diabetes and are FDA-approved for that. They are given by subcutaneous injection. Semaglutide is also FDA-approved for weight loss in non-diabetics if certain conditions are met.

Once-weekly semaglutide outperformed daily liraglutide in overweight and obese non-diabetics.

From JAMA Network:

Question Among adults with overweight or obesity without diabetes, what is the effect of once-weekly subcutaneous semaglutide, 2.4 mg, vs once-daily subcutaneous liraglutide, 3.0 mg, on weight loss when each is added to counseling for diet and physical activity?

Findings In this randomized clinical trial that included 338 participants, mean body weight change from baseline to 68 weeks was –15.8% with semaglutide vs –6.4% with liraglutide, a statistically significant difference.

Meaning Among adults with overweight or obesity without diabetes, once-weekly subcutaneous semaglutide, compared with once-daily subcutaneous liraglutide, added to counseling for diet and physical activity resulted in significantly greater weight loss at 68 weeks.

For prevention or improvement of overweight- and obesity-related illnesses, aim for loss of at least 5 to 10% of body weight. Assuming you’re overweight or obese in the first place. 16% body weight change is significant. 16% of 300 pounds (136 kg) would be 48 pounds (22 kg).

Steve Parker, M.D.

Evidence for Ancient Beer and Porridge

Photo by LilacDragonfly on

Interesting article in Nature from June 2021:

On a clear day, the view from the ruins of Göbekli Tepe stretches across southern Turkey all the way to the Syrian border some 50 kilometres away. At 11,600 years old, this mountaintop archaeological site has been described as the world’s oldest temple — so ancient, in fact, that its T-shaped pillars and circular enclosures pre-date pottery in the Middle East.

The people who built these monumental structures were living just before a major transition in human history: the Neolithic revolution, when humans began farming and domesticating crops and animals. But there are no signs of domesticated grain at Göbekli Tepe, suggesting that its residents hadn’t yet made the leap to farming. The ample animal bones found in the ruins prove that the people living there were accomplished hunters, and there are signs of massive feasts. Archaeologists have suggested that mobile bands of hunter-gatherers from all across the region came together at times for huge barbecues, and that these meaty feasts led them to build the impressive stone structures.

Now that view is changing, thanks to researchers such as Laura Dietrich at the German Archaeological Institute in Berlin. Over the past four years, Dietrich has discovered that the people who built these ancient structures were fuelled by vat-fulls of porridge and stew, made from grain that the ancient residents had ground and processed on an almost industrial scale1. The clues from Göbekli Tepe reveal that ancient humans relied on grains much earlier than was previously thought — even before there is evidence that these plants were domesticated. And Dietrich’s work is part of a growing movement to take a closer look at the role that grains and other starches had in the diet of people in the past.

The researchers are using a wide range of techniques — from examining microscopic marks on ancient tools to analysing DNA residues inside pots. Some investigators are even experimentally recreating 12,000-year-old meals using methods from that time. Looking even further back, evidence suggests that some people ate starchy plants more than 100,000 years ago. Taken together, these discoveries shred the long-standing idea that early people subsisted mainly on meat — a view that has fuelled support for the palaeo [sic] diet, popular in the United States and elsewhere, which recommends avoiding grains and other starches.

Steve Parker, M.D.

Paleo Diet Linked to Cardiovascular Benefits

A score appraising Paleolithic diet and the risk of cardiovascular disease in a Mediterranean prospective cohort


Purpose: To assess the association between a score appraising adherence to the PaleoDiet and the risk of cardiovascular disease (CVD) in a Mediterranean cohort.

Methods: We included 18,210 participants from the Seguimiento Universidad de Navarra (SUN) cohort study. The PaleoDiet score comprised six food groups promoted within this diet (fruit, nuts, vegetables, eggs, meat and fish) and five food groups whose consumption is discouraged (cereals and grains, dairy products, legumes, culinary ingredients, and processed/ultra-processed foods). CVD was defined as acute myocardial infarction with or without ST elevation, non-fatal stroke and cardiovascular death. Cox proportional hazards models adjusted for potential confounders were fitted to assess the association between the PaleoDiet score and CVD risk, and the PaleoDiet and MedDiet indices to explore differences between both diets.

Results: During 12.2 years of follow-up, 165 incident CVD cases were confirmed. A significant inverse association was found between the PaleoDiet score and CVD (HR Q5 vs. Q1: 0.45, 95% CI 0.27-0.76, P for trend = 0.007). A weaker association that became non-significant was observed when the item for low consumption of ultra-processed foods was removed from the score. Joint analysis of PaleoDiet and MedDiet Trichopoulou scores suggested that the inverse association between PaleoDiet and CVD was mainly present when adherence to the MedDiet was also high (HR for high adherence vs low adherence to both diet scores: 0.22, 95% CI 0.08-0.64).

Conclusions: Our findings suggest that the PaleoDiet may have cardiovascular benefits in participants from a Mediterranean country. Avoidance of ultra-processed foods seems to play a key role in this inverse association.

Link to European Journal of Nutrition article.

I was glad to see some new names among the researchers.

Steve Parker, M.D.

PS: If you’ve abandoned your New Years’ diet resolution, consider the Paleobetic Diet!

Paleo Diet: More Carbohydrates Than We Think?

Photo by Andru00e9 Cook on

I haven’t read the full article in Journal of Human Evolution because I don’t want to part with $20 it costs. Here’s the abstract:

Evidence for plants rarely survives on Paleolithic sites, while animal bones and biomolecular analyses suggest animal produce was important to hominin populations, leading to the perspective that Neanderthals had a very-high-protein diet. But although individual and short-term survival is possible on a relatively low-carbohydrate diet, populations are unlikely to have thrived and reproduced without plants and the carbohydrates they provide. Today, nutritional guidelines recommend that around half the diet should be carbohydrate, while low intake is considered to compromise physical performance and successful reproduction. This is likely to have been the same for Paleolithic populations, highlighting an anomaly in that the basic physiological recommendations do not match the extensive archaeological evidence. Neanderthals had large, energy-expensive brains and led physically active lifestyles, suggesting that for optimal health they would have required high amounts of carbohydrates. To address this anomaly, we begin by outlining the essential role of carbohydrates in the human reproduction cycle and the brain and the effects on physical performance. We then evaluate the evidence for resource availability and the archaeological evidence for Neanderthal diet and investigate three ways that the anomaly between the archaeological evidence and the hypothetical dietary requirements might be explained. First, Neanderthals may have had an as yet unidentified genetic adaptation to an alternative physiological method to spare blood glucose and glycogen reserves for essential purposes. Second, they may have existed on a less-than-optimum diet and survived rather than thrived. Third, the methods used in dietary reconstruction could mask a complex combination of dietary plant and animal proportions. We end by proposing that analyses of Paleolithic diet and subsistence strategies need to be grounded in the minimum recommendations throughout the life course and that this provides a context for interpretation of the archaeological evidence from the behavioral and environmental perspectives.

Easy Ways to Prevent COVID-19

Artist’s renditions of coronavirus

Oral preventatives during disease surges:

  • Vitamin D (cholecalciferol) 1,000-2,000 IU/day. (Gruff Davies and Linda Benskin recommend, in general, 4,000 IU daily, perhaps year-round, or whatever combination of food, supplementation, and sunlight gets your blood level of 25-hydroxy vitamin D to to 50 ng/mL.)
  • Aspirin 81-325 mg/day
  • Vitamin C 500 mg/day
  • Elemental zinc 10-50 mg/day
  • Melatonin 1.5-6 mg/day at night or bedtime

The doses vary, depending on body weight, age, tolerance to the drug. Generally, the higher doses are for younger and heavier folks. If one gets plentiful sunlight exposure, the oral vitamin D may not be needed.

Other strategies during disease surges (or always?):

  • Regular exercise
  • Lose excess weight, especially if obese (BMI over 30)
  • Maintain normal blood sugars (if diabetic, keep HgbA1c under 6.5%)
  • Avoid close, prolonged contact with coughing and sneezing people, especially in enclosed spaces
  • Frequent hand-washing if exposed to public doorknobs, elevator buttons, or other potentially contaminated surfaces, or if around sick (coughing and/or sneezing) people
  • Avoid sick people who are coughing and sneezing
  • Eat healthful food

Alternatively, from Dr Robert Malone on his Dec 31, 2021 substack:

“So, yes back to my thoughts on Omicron – please keep taking that vitamin D3 and get your levels tested, if you haven’t already.  Use a formulation that combines the D3 with Vitamins A and K. Please keep up with the zinc, vitamin C and magnesium.  Work on weight control, glycemic control and please exercise!  All are important.”

Did you notice I haven’t mentioned masks? I’m not a big believer. Do I wear an N-95 mask when I’m seeing a COVID-19 patient at the hospital? You bet. And the mask was fit-tested. Is that testing available to the general public? Not that I’m aware.

Do I have great data to support all these strategies? No, but some. Are they recommended by the CDC or NIH (Nat’l Institutes of Health)? I don’t know or care. I’ve lost faith in them. I’m afraid they’ve been bought and paid for by Big Pharma (and others?).

I don’t know about your personal health and medical history. I’m not your doctor. If you’re considering any of these recommendations, consult your personal physician before implementation.

The patient is wise to look away. If you watch the needle go in, it’ll hurt more.

I was motivated to write this post by the failures and risks of the rushed vaccines. Vaccination might be helpful if you are sickly, over 65, or have underlying conditions such as diabetes, active cancer, a poor immune system, obesity (especially BMI over 35), or some other co-morbidities. I see both very healthy, vigorous 65-year-olds, and sickly 65-year-olds. Which one are you? If you’re over 80, you may have nothing to lose by vaccinating. Average U.S. life expectancy is 79 years, less for men, longer for women.

Steve Parker, M.D.