Some Diets Are Better Than Others at Lowering Blood Pressure

paleobetic diet, low-carb diet
Vegetarian: One cup of Waldorfian salad (search site for recipe)

Increasingly, I’m suspicious of results from meta-analyses. Anyway, here’s the abstract of one from American Journal of Clinical Nutrition in 2020. In case you’re like me and not familiar with the LDL-lowering, vegetarian, “portfolio diet,” click for an infographic.

Background: Many systematic reviews and meta-analyses have assessed the efficacy of dietary patterns on blood pressure (BP) lowering but their findings are largely conflicting.

Objective: This umbrella review aims to provide an update on the available evidence for the efficacy of different dietary patterns on BP lowering.

Methods: PubMed and Scopus databases were searched to identify relevant studies through to June 2020. Systematic reviews with meta-analyses of randomized controlled trials (RCTs) were eligible if they measured the effect of dietary patterns on systolic (SBP) and/or diastolic blood pressure (DBP) levels. The methodological quality of included systematic reviews was assessed by A Measurement Tool to Assess Systematic Review version 2. The efficacy of each dietary pattern was summarized qualitatively. The confidence of the effect estimates for each dietary pattern was graded using the NutriGrade scoring system.

Results: Fifty systematic reviews and meta-analyses of RCTs were eligible for review. Twelve dietary patterns namely the Dietary Approaches to Stop Hypertension (DASH), Mediterranean, Nordic, vegetarian, low-salt, low-carbohydrate, low-fat, high-protein, low glycemic index, portfolio, pulse, and Paleolithic diets were included in this umbrella review. Among these dietary patterns, the DASH diet was associated with the greatest overall reduction in BP with unstandardized mean differences ranging from -3.20 to -7.62 mmHg for SBP and from -2.50 to -4.22 mmHg for DBP. Adherence to Nordic, portfolio, and low-salt diets also significantly decreased SBP and DBP levels. In contrast, evidence for the efficacy of BP lowering using the Mediterranean, vegetarian, Paleolithic, low-carbohydrate, low glycemic index, high-protein, and low-fat diets was inconsistent.

Conclusion: Adherence to the DASH, Nordic, and portfolio diets effectively reduced BP. Low-salt diets significantly decreased BP levels in normotensive Afro-Caribbean people and in hypertensive patients of all ethnic origins.

Source: Efficacy of different dietary patterns on lowering of blood pressure level: an umbrella review – PubMed

Steve Parker, M.D.

Ketogenic Diet Improved Non-Alcoholic Fatty Liver Disease In Just Six Days

stages of liver damage

There’s a silent epidemic in folks with type 2 diabetes: 50 to 70% have non-alcoholic fatty liver disease. Non-alcoholic fatty liver disease is an important contributor to cirrhosis, i.e., scarring in the liver that impairs liver function. In the study at hand, a ketogenic diet reduced liver fat by 31% over just six days. I don’t have many details of the diet used, but it reduced carbohydrates to 20 grams/day.

Significance

Ketogenic diet is an effective treatment for nonalcoholic fatty liver disease (NAFLD). Here, we present evidence that hepatic mitochondrial fluxes and redox state are markedly altered during ketogenic diet-induced reversal of NAFLD in humans. Ketogenic diet for 6 [days] markedly decreased liver fat content and hepatic insulin resistance. These changes were associated with increased net hydrolysis of liver triglycerides and decreased endogenous glucose production and serum insulin concentrations. Partitioning of fatty acids toward ketogenesis increased, which was associated with increased hepatic mitochondrial redox state and decreased hepatic citrate synthase flux. These data demonstrate heretofore undescribed adaptations underlying the reversal of NAFLD by ketogenic diet and highlight hepatic mitochondrial fluxes and redox state as potential treatment targets in NAFLD.

Abstract

Weight loss by ketogenic diet (KD) has gained popularity in management of nonalcoholic fatty liver disease (NAFLD). KD rapidly reverses NAFLD and insulin resistance despite increasing circulating nonesterified fatty acids (NEFA), the main substrate for synthesis of intrahepatic triglycerides (IHTG). To explore the underlying mechanism, we quantified hepatic mitochondrial fluxes and their regulators in humans by using positional isotopomer NMR tracer analysis. Ten overweight/obese subjects received stable isotope infusions of: [D7]glucose, [13C4]β-hydroxybutyrate and [3-13C]lactate before and after a 6-d KD. IHTG was determined by proton magnetic resonance spectroscopy (1H-MRS). The KD diet decreased IHTG by 31% in the face of a 3% decrease in body weight and decreased hepatic insulin resistance (−58%) despite an increase in NEFA concentrations (+35%). These changes were attributed to increased net hydrolysis of IHTG and partitioning of the resulting fatty acids toward ketogenesis (+232%) due to reductions in serum insulin concentrations (−53%) and hepatic citrate synthase flux (−38%), respectively. The former was attributed to decreased hepatic insulin resistance and the latter to increased hepatic mitochondrial redox state (+167%) and decreased plasma leptin (−45%) and triiodothyronine (−21%) concentrations. These data demonstrate heretofore undescribed adaptations underlying the reversal of NAFLD by KD: That is, markedly altered hepatic mitochondrial fluxes and redox state to promote ketogenesis rather than synthesis of IHTG.

Source: Effect of a ketogenic diet on hepatic steatosis and hepatic mitochondrial metabolism in nonalcoholic fatty liver disease | PNAS

Steve Parker, M.D.

High Glycemic Index Diet Linked to Cardiovascular Disease and Premature Death

Low glycemic index meal

Haven’t we know this for years? From a recent New England Journal of Medicine:

Most data regarding the association between the glycemic index and cardiovascular disease come from high-income Western populations, with little information from non-Western countries with low or middle incomes. To fill this gap, data are needed from a large, geographically diverse population.

METHODS

This analysis includes 137,851 participants between the ages of 35 and 70 years living on five continents, with a median follow-up of 9.5 years. We used country-specific food-frequency questionnaires to determine dietary intake and estimated the glycemic index and glycemic load on the basis of the consumption of seven categories of carbohydrate foods. We calculated hazard ratios using multivariable Cox frailty models. The primary outcome was a composite of a major cardiovascular event (cardiovascular death, nonfatal myocardial infarction, stroke, and heart failure) or death from any cause.

RESULTS

In the study population, 8780 deaths and 8252 major cardiovascular events occurred during the follow-up period. After performing extensive adjustments comparing the lowest and highest glycemic-index quintiles, we found that a diet with a high glycemic index was associated with an increased risk of a major cardiovascular event or death, both among participants with preexisting cardiovascular disease (hazard ratio, 1.51; 95% confidence interval [CI], 1.25 to 1.82) and among those without such disease (hazard ratio, 1.21; 95% CI, 1.11 to 1.34). Among the components of the primary outcome, a high glycemic index was also associated with an increased risk of death from cardiovascular causes. The results with respect to glycemic load were similar to the findings regarding the glycemic index among the participants with cardiovascular disease at baseline, but the association was not significant among those without preexisting cardiovascular disease.

CONCLUSIONS

In this study, a diet with a high glycemic index was associated with an increased risk of cardiovascular disease and death.

Source: Glycemic Index, Glycemic Load, and Cardiovascular Disease and Mortality | NEJM

The paleo diet is low glycemic index.

Steve Parker, M.D.

Is Biden Responsible for the High Cost of Insulin?

Hamburger-Avocado Salad with tomatoes, cucumbers, lettuce, salt/pepper, and olive oil vinaigrette

Newsweek looks at the issue.

In any case, why not reduce your need for insulin with low-carb eating?

Steve Parker, M.D.

Gastric Bypass Cuts Risk of Retinopathy in Type 2 Diabetes

Photo of the retina at the back of the eyeball

Retinopathy is a fancy word meaning disease of the retina, the light detecting membrane at the back of the eyeball. About two in five folks with diabetes have some form or degree of diabetic retinopathy. The pathology is mostly in the arterial blood vessels of the retina. Keeping blood sugars under good control is one way to prevent diabetic retinopathy. Once diagnosed, it can be treated with injections, lasers, or surgery.

Steve Parker MD, bariatric surgery, gastric bypass
Band Gastric Bypass Surgery

Here’s the abstract from a recent scientific report the looked at the ocular effects of gastric bypass surgery in obese type 2 diabetics. Over the course of 4.5 years, the risk of diabetic retinopathy was 40% less in those who had bypass surgery.

Importance  Knowledge of the incidence and progression of diabetic retinopathy (DR) after gastric bypass surgery (GBP) in patients with obesity and diabetes could guide the management of these patients.

Objective  To investigate the incidence of diabetic ocular complications in patients with type 2 diabetes after GBP compared with the incidence of diabetic ocular complications in a matched cohort of patients with obesity and diabetes who have not undergone GBP.

Design, Setting, and Participants  Data from 2 nationwide registers in Sweden, the Scandinavian Obesity Surgery Registry and the National Diabetes Register, were used for this cohort study. A total of 5321 patients with diabetes from the Scandinavian Obesity Surgery Registry who had undergone GBP from January 1, 2007, to December 31, 2013, were matched with 5321 patients with diabetes from the National Diabetes Register who had not undergone GBP, based on sex, age, body mass index (BMI), and calendar time (2007-2013). Follow-up data were obtained until December 31, 2015. Statistical analysis was performed from October 5, 2018, to September 30, 2019.

Exposure  Gastric bypass surgery.

Main Outcomes and Measures  Incidence of new DR and other diabetic ocular complications.

Results  The study population consisted of 5321 patients who had undergone GBP (3223 women [60.6%]; mean [SD] age, 49.0 [9.5] years) and 5321 matched controls (3395 women [63.8%]; mean [SD] age, 47.1 [11.5] years). Mean (SD) follow-up was 4.5 (1.6) years. The mean (SD) BMI and hemoglobin A1c concentration at baseline were 42.0 (5.7) and 7.6% (1.5%), respectively, in the GBP group and 40.9 (7.3) and 7.5% (1.5%), respectively, in the control group. The mean (SD) duration of diabetes was 6.8 (6.3) years in the GBP group and 6.4 (6.4) years in the control group. The risk for new DR was reduced in the patients who underwent GBP (hazard ratio, 0.62 [95% CI, 0.49-0.78]; P < .001). The dominant risk factors for development of DR at baseline were diabetes duration, hemoglobin A1c concentration, use of insulin, glomerular filtration rate, and BMI.

Conclusions and Relevance  This nationwide matched cohort study suggests that there is a reduced risk of developing new DR associated with GBP, and no evidence of an increased risk of developing DR that threatened sight or required treatment.

Click for full text.

Steve Parker, M.D.

How to Prevent Age-Related Muscle Loss

paleo diet, low-carb, Steve Parker MD
This hunter-gatherer snagged himself a brown trout

Axel Sigurdsson, MD, PhD, published a great article on prevention of age-related sarcopenia (loss of muscle mass). Click through for details. To stay vigorous as you age, you should preserve muscle mass and the strength it provides. If you’ve lost muscle mass, you can re-build it. Summary from the good doctor:

Age-related loss of muscle mass (sarcopenia)may start as early as in our thirties and appears to continue for the rest of our lives.

There is also a loss of muscle strength and muscle function. The consequences may often be severe, particularly in the elderly.

Increased physical activity and adequate nutrition are the most powerful tools at our disposal to delay age-related loss of muscle mass.

Well-rounded exercise programs consisting of aerobic and resistance exercises are believed to be most effective

Modification of dietary habits may be an important tool to prevent the decline in muscle mass and function that occurs with aging.

Adequate protein intake is of key importance. Animal-derived protein may provide a higher and broader biological value than vegetable protein.

Fish consumption is recommended and fruits and vegetables should be consumed regularly.

Nutritional supplements containing essential amino acids may be helpful. This is particularly true for whey protein.

Fish-derived protein hydrolysates also appear promising.

Adequate intake of vitamin D is essential.

“Fish-derived protein hydrolysates” doesn’t sound very appetizing. I’ll stick with real fish for now, especially cold-water fatty fish.

Steve Parker, M.D.

Liver Fat and Fibrosis Are Common in Type 2 Diabetes

A 2021 issue of Diabetes Care reveals the shocking prevalence of advanced liver fibrosis (scarring) in folks with type 2 diabetes: one of every six. Fibrosis may eventually lead to cirrhosis and require a liver transplant. The study at hand used vibration-controlled transient elastography to measure liver stiffness. The more fibrosis, the stiffer the liver. The measuring device “uses a pulse-echo ultrasound technique to quantify the speed of mechanically induced shear wave within liver tissue,” which correlates with the severity of fibrosis. Liver fat, i.e., steatosis, can also be quantified at the same time by measuring the ultrasonic attenuation of the echo wave. 

Here’s the study abstract:

OBJECTIVE

Assess the prevalence of nonalcoholic fatty liver disease (NAFLD) and of liver fibrosis associated with nonalcoholic steatohepatitis in unselected patients with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

A total of 561 patients with T2DM (age: 60 ± 11 years; BMI: 33.4 ± 6.2 kg/m2; and HbA1c: 7.5 ± 1.8%) attending primary care or endocrinology outpatient clinics and unaware of having NAFLD were recruited. At the visit, volunteers were invited to be screened by elastography for steatosis and fibrosis by controlled attenuation parameter (≥274 dB/m) and liver stiffness measurement (LSM; ≥7.0 kPa), respectively. Secondary causes of liver disease were ruled out. Diagnostic panels for prediction of advanced fibrosis, such as AST-to-platelet ratio index (APRI) and Fibrosis-4 (FIB-4) index, were also measured. A liver biopsy was performed if results were suggestive of fibrosis.

RESULTS

The prevalence of steatosis was 70% and of fibrosis 21% (LSM ≥7.0 kPa). Moderate fibrosis (F2: LSM ≥8.2 kPa) was present in 6% and severe fibrosis or cirrhosis (F3–4: LSM ≥9.7 kPa) in 9%, similar to that estimated by FIB-4 and APRI panels. Noninvasive testing was consistent with liver biopsy results. Elevated AST or ALT ≥40 units/L was present in a minority of patients with steatosis (8% and 13%, respectively) or with liver fibrosis (18% and 28%, respectively). This suggests that AST/ALT alone are insufficient as initial screening. However, performance may be enhanced by imaging (e.g., transient elastography) and plasma diagnostic panels (e.g., FIB-4 and APRI).

CONCLUSIONS

Moderate-to-advanced fibrosis (F2 or higher), an established risk factor for cirrhosis and overall mortality, affects at least one out of six (15%) patients with T2DM. These results support the American Diabetes Association guidelines to screen for clinically significant fibrosis in patients with T2DM with steatosis or elevated ALT.

Source: Advanced Liver Fibrosis Is Common in Patients With Type 2 Diabetes Followed in the Outpatient Setting: The Need for Systematic Screening | Diabetes Care

The good news is that excessive liver fat (aka hepatic steatosis), a precursor to fibrosis, can be reversed to a great degree.

Steve Parker, M.D.

Meta-Analysis: Paleolithic diet effects on glucose metabolism and lipid profile among patients with metabolic disorders

See modern man walking off that cliff?

From mostly Iran-based researchers, published in Critical Reviews in Food Science and Nutrition:

Abstract

Objective:

Several randomized clinical trials (RCTs) have investigated the effects of the Paleolithic diet (PD) in adult patients suffering from metabolic disorders. However, the results of these RCTs are conflicting. Therefore, we conducted a systematic review and meta-analysis to assess the effects of the PD in patients with metabolic disorders.

Methods:

We searched the PubMed/Medline, Scopus, Cochrane Databases, Google Scholar, Web of Science, and Embase databases up to June, 2020. The data were pooled using a random-effects model. From the eligible publications, 10 articles were selected for inclusion in this systematic review and meta-analysis. The meta-analysis was performed using a random-effects model. The heterogeneity was determined using the I2 statistics and the Cochrane Q test.

Results:

The pooled results from the random-effects model showed a significant reduction of the homeostatic model assessment of insulin resistance (HOMA-IR) (weighted mean difference, WMD: -0.39, 95% CI: -0.70, -0.08), fasting insulin (WMD: -12.17 μU/mL, 95% CI: -24.26, -0.08), total cholesterol (WMD: -0.32 mmol/l, 95% CI: -0.49, -0.15), triglycerides (WMD: -0.29 mmol/L, 95% CI: -0.42, -0.16), low-density lipoprotein cholesterol (WMD: -0.35 mmol/L, 95% CI: -0.67, -0.03), blood pressure (BP)(WMD – 5.89 mmHg; 95% CI – 9.973 to – 1.86 for the systolic BP and WMD – 4.01 mmHg; 95% CI – 6.21 to – 1.80 for the diastolic BP values) and C-reactive protein (CRP) levels (WMD: -0.84, mg/L, 95% CI: -1.62, -0.06) in the PD group versus control group.

Conclusions:

Our findings provide better insights into the effect of the PD on the modulation of the glucose and lipid metabolism factors in patients with metabolic disorders, providing comprehensive information for the development of future RCTs with a high quality design.

Source: The effect of paleolithic diet on glucose metabolism and lipid profile among patients with metabolic disorders: a systematic review and meta-analysis of randomized controlled trials – PubMed

Could a paleolithic lifestyle intervention help breast cancer patients undergoing radiotherapy?

A modern paleo meal

We don’t know from the study at hand.

This pilot and feasibility study involved only 11 patients that completed the study. The main finding was a loss of about a pound of fat weight weekly. Hey abstract writer, how about telling us how long the study lasted? Anyway, breast cancer patients primarily want to know what a particular management approach will do for their cure rate and quality of life.

Abstract

Evolutionary principles are rarely considered in clinical oncology. We here aimed to test the feasibility and effects of a dietary and physical activity intervention based on evolutionary considerations in an oncological setting. A total of 13 breast cancer patients referred to our clinic for curative radiotherapy were recruited for this pilot study. The women were supposed to undertake a “Paleolithic lifestyle” (PL) intervention consisting of a Paleolithic diet and daily outdoor activity of at least 30 min duration while undergoing radiotherapy. Body composition was measured weekly by bioimpedance analysis. Blood parameters were assessed before, during, and at the end of radiotherapy. A control group on an unspecified standard diet (SD) was assigned by propensity score matching. A total of eleven patients completed the study. The majority of patients (64%) reported feeling good or very good during the intervention. The intervention group experienced an average decrease of 0.4 kg body weight (p < 0.001) and 0.34 kg (p < 0.001) fat mass per week, but fat-free and skeletal muscle mass were not significantly affected. Vitamin D levels increased slightly from 23.8 (11-37.3) ng/ml to 25.1 (22.6-41.6) ng/ml (p = 0.053). β-hydroxybutyrate levels were significantly increased and triglycerides and free T3 hormone levels significantly reduced by the PL intervention. This pilot study shows that adoption of a PL intervention during curative radiotherapy of breast cancer patients is feasible and able to reduce fat mass. Daily outdoor activity could eliminate vitamin D deficiency (vitamin D < 20 ng/ml). Future studies are needed to confirm these findings.

Source: Short-term effects of a Paleolithic lifestyle intervention in breast cancer patients undergoing radiotherapy: a pilot and feasibility study – PubMed

We don’t know if the paleo diet prevents breast cancer. But I know one diet that does: the traditional Mediterranean diet.

Steve Parker, M.D.

Do You Have Any Recourse If Injured By the COVID-19 Vaccine?

needle, syringe, vaccine, vaccination, covid-19
The vaccination needle probably won’t be this large

I know it’s a little early to be asking that question. Within a year, an unknown number of you will be asking. Where do you go for satisfaction? The CICP: Countermeasures Injury Compensation Program. Forget about suing the vaccine manufacturer, distributor, or medical practitioner who jabbed you. They got the federal government to absolve them of liability in most cases. If injured, you need to file your claim within a year of vaccination.

As far as I know, this program only applies to U.S. residents. Perhaps only U.S. citizens.

Here’s an excerpt from a related fedgov program, the NVICP web page:

Vaccines save lives by preventing disease.

Most people who get vaccines have no serious problems. Vaccines, like any medicines, can cause side effects, but most are very rare and very mild. Some health problems that follow vaccinations are not caused by vaccines.

In very rare cases, a vaccine can cause a serious problem, such as a severe allergic reaction.  

In these instances, the National Vaccine Injury Compensation Program (VICP) may provide financial compensation to individuals who file a petition and are found to have been injured by a VICP-covered vaccine. Even in cases in which such a finding is not made, petitioners may receive compensation through a settlement. 

Many physicians in my community are excited and lined up to take the COVID-19 vaccine. But not me. I even have risk factors for more serious COVID-19 disease: age 66 and hypertension. After reviewing what little data are available from the Warp Speed vaccine trials, I’m not convinced the vaccines are safe enough for me. I’ll take my chances with the virus rather than the vaccine. I’m not afraid of dying from COVID-19; if that happens I’ll be in heaven with Jesus. I’ve lived a full and lucky life, blessed by a wonderful wife, fantastic children, good health, missed Viet Nam by a few years, no major economic upheaval. My biggest concern about catching the virus is the burden it would lay on my co-workers if I’m off-duty for 1 to 3 weeks.

At her age, great odds of surviving COVID-19

That said, if I were older and had other co-morbidities, I might take the vaccine now. When we have more long-term data on vaccine safety, I might take the vaccine. It could take up to a couple years before we have that data.

I am not anti-vaccine, in general. As a child I got the vaccines for polio, measles, mumps, rubella, tetanus, and probably diphtheria, maybe others. I took the hepatitis B vaccine as an adult because I’m exposed to blood from my patients. I’m due for another tetanus booster and will take it without reservation.

Steve Parker, M.D.

PS: I’m doing everything I can to optimize my health and immune system, including weight management and regular exercise.

PPS: Pharmacist Scott Gavura at Science Based Medicine provides a table comparing vaccination vs catching the virus vs hydroxychloroquine treatment. He implies my odds of death from COVID-19 infection are two out of a hundred (2%). I don’t think it’s nearly that high.

PPPS: Click for an interesting article on CICP at the Centre for Research on Globalization. I have no idea of its accuracy.