Dietary recommendations continue to be one of the most confusing topics in modern medicine simply because of the paucity of good data and the complexity of randomization within these studies. It seems like every day something new comes out challenging the peaceful paradigm of what seems intuitive. The most widely accepted dietary regimen for the last 40 years is the Mediterranean Diet which advocated largely plant-based foods, unsaturated fats such as olive oil, and copious fruits and vegetables. As part of this, it is postulated that red meats should be limited to only a few meals per month; many prominent Cardiologists support this recommendation as part of the plant based diet, which has gained tremendous popularity.
An article published by Dr. Daniel Dressler et al in the Annals of Internal Medicine October 2019, however, raises eyebrows to the data behind these recommendations. Because of the significance of this, this article was even highlighted as one 12 significant “guideline changing” articles within NEJM Guideline Watch 2020.
As part of the study, an independent research panel scoured literature underpinning associations between red meat consumption and multiple disease markers, and highlighted several concerning limitations: Most studies were observational studies with high risk of bias, poor statistical methodology, and inordinate amounts of cultural and population bias. Meta-analysis of 12 randomized controlled trials with over 10 year follow-up on all cause mortality (including cancer markers, heart disease, development of diabetes, etc.) showed no statistical significance between patients who consumed high or low quantities of red meat. This difference was defined by greater than 3 servings reduction in red meat per week; does this mean that patient’s with even tighter reduction in red meats would yield the same result? What about outcomes from those consuming extremely high quantities of red meat? We don’t know! This article supports the ambiguity here, and highlights the need to perform more research prior to defining causation.
Nothing in the article argues harm from reducing red meat consumption, and personally I would recommend to continue to do so, but it highlights the need to question dietary regimens that seem too black and white amidst this enormously challenging and controversial field.
Dressler, Daniel MD et al. Guideline for Consumption of Unprocessed Red Meat and Processed Meat. Annals of Internal Medicine, Oct 1 2019.
B12 is one of the most widely supplemented vitamins, in part, because of its broad clinical significance. Most people correlate B12 levels to overall energy and vitality, but the broader implications may be more subtle. Below we highlight these lesser known elements:
1. B12 is synthesized by microorganisms and found in only trace amounts mostly in foods of animal origin, such as chicken or fish, yogurt, or cheese. This means that the absorption apparatus into the blood stream is ever so important. The most common cause of B12 deficiency (pernicious anemia) is due to impairment in transport simply because some people lack the critical enzyme to do so
2. B12 deficiency causes low energy through its direct impact on red blood cell production. In fact, B12 is needed for proper cell division which explains why large red blood cells are the diagnostic cue, even before anemia or fatigue develop. These changes are reversible and can be normalized with supplementation.
3. B12 is a critical vitamin involved in the myelin sheath of neuron development. This acts as the outer coat of your body’s electrical pathways. Imagine if you have frayed wires all throughout the circuitry of your old house? B12 deficiency often presents with balance and sensory issues but can evolve into a number of neurological diseases if left untreated.
4. Direct B12 testing is widely available to make a quick clinical diagnosis, but it becomes less clear when the value is borderline. Two other lab tests, homocysteine and methylmalonic acid are involved in B12 metabolism and important to confirm the diagnosis when in this gray zone. If both of these results are elevated it strongly supports a clinical need for supplementation.
5. Homocysteine is emerging as a risk factor for heart disease and stroke when elevated. If your homocysteine level is increased due to low B12 this is an easy solution to protect two of your most critical organs.
6. B12 comes in many formulations: IV, intramuscular, oral, sublingual, intranasal, and even transdermal patches. Patient’s even with pernicious anemia can find relief with high dose oral formulations (1-2mg daily), but intravenous and intramuscular formulations reach higher levels more quickly and reliably especially if pathology exists in the stomach or small intestine. Effective treatment will often correct blood abnormalities within 2 months and neurological symptoms within 6 months.
Stabler, Sally P. New England Journal of Medicine. 2013;368:149-160
Dr Viglione is an internal medicine concierge doctor in Santa Barbara, CA