Does Red Meat Really Cause Cancer?

Earlier this week the World Health Organization (WHO) announced that processed red meats are a “human carcinogen” and red meats a “probable human carcinogen” that increase your risk of cancer. Those are powerful words and unsurprisingly they spread like wildfire within just a few hours.

Perhaps not too many people are surprised to read that traditional processed meats (e.g. hot dogs, salamis, sausages), with so many fillers and additives, are not good for your gut health. But, where do naturally and pasture-raised meats without preservatives or additives, like bacon and homemade sausages fit in?

However, what many health professionals (including myself) are shocked about, is that red meat (e.g. steak, lamb, veal, etc.) was also included. Red meat is one of nature’s best sources of healthy fat, essential amino acids, iron, zinc, and B12 so how did it get lumped in with the processed meats?

Unfortunately, in today’s Twitter world of 140 characters or less, a controversial headline gets a lot of media play. Let’s take a closer look at the WHO summary and see what the document actually reveals.

Processed Red Meat is a Human Carcinogen

The WHO defined processed red meat as a “human carcinogen” because they believe there is sufficient evidence that the agent causes cancer in humans and/or animals. They believe (and there is good evidence) that carcinogenic compounds like nitrosamines and polycylic aromatic hydrocarbons (PAHs) – produced during curing, salting and smoking – are leading to an increase risk of cancers. It’s these specific compounds that worries the WHO and led to their conclusions.

The Group 1 category also includes things like smoking, radiation, plutonium, etc. However, the report notes that just because smoking and processed red meat are both included in Group 1, it doesn’t mean they confer the same risk of cancer.

Relative Risk vs. Absolute Risk

The report states that processed red meat and red meat consumption increases your risk of colorectal cancer (not all types of cancer) by 17% for every 100g. This seems high, but you must remember that “relative risk” is a statistical term researchers use to compare the risk between two groups.

For example, the WHO has just stated you’re at 17% increase risk of colorectal cancer if you eat processed red meat. However, your true risk getting this type of cancer – called absolute risk– is only 5% for your lifetime according to the American Cancer Society.1 Using the relative risk term typically makes the “risk” seem greater than it actually is.

Other major risk factors for colorectal cancer are smoking, weight gain, obesity, diabetes, low fiber diet, sedentary lifestyle and alcohol use. If the meat you consume is placed between two buns with an order of fries and a sugar-laden soda at a fast food restaurant, then your choices will definitely be putting you at greater risk. However, it’s very different if you eat red meat as part of a healthy diet, rich vegetables, healthy fats and complex carbohydrates.

Why Is Red Meat Lumped In With Processed Meat?

This is where things get very grey. The direct quote for classifying red meat as a “possible carcinogen” in the report is based on, “limited evidence from epidemiological studies… that a positive association has been observed.” The evidence from the report gets even more speculative in the next sentence, stating “other explanations for the association (chance, bias, confounders) could not be ruled out”.

Association is not causation. Fire trucks appear at every fire in the city, and therefore are associated with fires, but they do not cause fires. The most troubling statement is that the relationship is so thin that “coincidence” or “luck” might explain the association. In fact, the WHO stated in their report that “red meat has known health benefits”, but not surprisingly this didn’t make the media headlines. Why then the tough stance on red meat?

High Temperature Cooking & Carcinogens

The root of the WHO’s concern with processed and natural red meat seems to stem from how we cook it. When we cook red meat – grilling, sautéing, searing, etc – it can lead to the production of carcinogenic compounds called nitrosamine, heterocyclic amines (HAs) or polycyclic aromatic hydrocarbons (PAHs), if it’s cooked with an open flame. These compounds are the real “bad guys” the WHO is concerned about and the likeliest reason processed red meat was included in Group 1 “human carcinogen” and red meat included in the Group 2A “possible carcinogen” category. However, what isn’t included in the report is that PAHs are found in the same concentrations in vegetables and grains, and even more concerning, virtually double the amount in the ambient environment (i.e. dust).2,3 That’s right, you get just as much PAHs from the rest of your dinner plate and are virtually exposed to them everyday in the environment. Seems unlikely they alone are the smoking gun.

Can You Mitigate The Negative Effects of Cooking Red Meat?

The good news is there are numerous cooking techniques that help to mitigate the potential negative effects of grilling or sautéing your meat. For example, marinating your meats (spices, honey, vinegars, etc.), cooking at lower temperatures (slow-cooker, braising, simmering, etc.) and choosing medium-rare over a “well done” steak, all significantly reduce the formation of carcinogens.

The research also shows that if you add leafy greens or green vegetables with your red meat it offsets the DNA damage from these carcinogens.4 The vegetables you add to your plate, along with fruit and friendly starches – potatoes, rice, yams – dramatically increase your fiber intake, building up “good” gut bacteria and reducing your risk of colorectal cancer.

Remember, the biggest risk factors for colorectal cancer are sedentary lifestyle, weight gain, obesity, diabetes, lack of fiber and constipation. Physical inactivity leads to a 10% increase in risk of colon cancers, and for every 4 inches you add to your waist, your risk of colorectal cancer increases by 20%.5,6 For two-thirds of the population who are classified as overweight or obese, it is especially important to promote good gut health, physical activity and a high-fibre, low carbs/sugar diet to reduce risks. If your bowel movements don’t occur daily and you “miss” days in the week, toxins build-up in the large intestine and put you at greater risk of colorectal cancer.

Animal protein, especially red meat, is one of the most nutrient dense foods on the planet. Marinated, cooked at moderate temperature, and served over a plate of leafy greens as part of diet high in fiber (e.g. the Paleo diet), red meat promotes good health, slimmer waistline and improve body composition. I see this everyday in clinical practice. While too many processed meats do present a potential risk factor and should be consumed in moderation, if you stay active, maintain a healthy weight and fill your plate with leafy greens your lifetime risk of developing colorectal cancer is only 5%.

Yours in health,
Dr. Marc Bubbs ND, CSCS

Can Paleo Improve Low Mood and Depression?

Low mood and depression are increasingly prevalent symptoms of 21st century living. While the current statistics from the Center for Disease Control show one in ten people suffer from depression, in clinical practice we see much higher rates of people struggling with unreported low mood or depressive symptoms.

The World Health Organization has estimated that by the year 2050, one-third of the global population will suffer from either anxiety or depression. What is going on? Why are we more prone to depression today than in generations past?

As with any complex condition, there are many factors at play that conspire to create an environment where low mood and depression can thrive. Let’s look at how a Paleo diet can lay the framework for better mental health by addressing influential systems of the body.


Today, 75% of the North American population are classified as overweight or obese and the annual consumption of processed and simple sugars tops a whopping 160 pounds of sugar per person. This leads to worsening blood sugar control and insulin dysfunction. Research from Scandinavia has uncovered a clear association between elevated HbA1c (a three-month average of blood sugars) and insulin levels with increased risk of depression. A recent study found that young men with insulin resistance were three times more likely to suffer from severe depression.1

Another study in Diabetes Care of over 4,000 people showed depressive symptoms were associated with higher fasting and 30-minute insulin levels.2 The authors specifically noted that antidepressant medications did not alter this association because the medications target neurotransmitters (e.g. serotonin, dopamine) and do not address blood sugar and insulin dysfunction.

Adopting a Paleo diet can dramatically improve blood sugars and insulin levels, an important first step for reducing risk factors for low mood and depression.


Inflammation is another potential root cause of low mood. Low-grade systemic inflammation leads to the over-production of pro-inflammatory cytokines that are associated with depression.3 The prestigious New England Journal of Medicine recently published a review of the growing connection between chronic inflammation and the development of today’s most common chronic diseases, including depression.4 The current medical literature tells us that if you are overweight or obese, you likely have low-grade systemic inflammation.5

A Paleo diet’s high nutrient density provides a robust intake of antioxidants that help to cool inflammation and reduce the damaging effects of reactive oxygen species (ROS) produced during the inflammatory response. A Paleo diet is also a rich source of anti-inflammatory omega-3 fats that support positive mood. Studies show low levels of omega-3 fats are associated with a chronic stress state and increased risk of depression.6


The microflora of the gut plays a key role in your health and is in constant communication with the brain. Key neurotransmitters targeted by medications for improving symptoms of depression – serotonin and dopamine – are actually concentrated in the gut. The research shows that if you are overweight, you will likely have poor zonulin function, a key molecule that regulates gut permeability.(7)Poor zonulin function leads to symptoms of a leaky gut, which exacerbates inflammatory levels and can contribute to the cytokine storm that leads to low mood and depression.

You don’t need to be overweight to suffer from leaky gut. The research is clear that chronic or excessive use of NSAIDs – non-steroidal anti-inflammatory drugs – like ibuprofen and naproxen are also a direct cause of leaky gut, which will worsen inflammation.8,9A Paleo approach to eating supports the growth of good gut bacteria and, therefore, superior intestinal health.


Movement is a critical component of mental health and overall wellbeing. Busy workdays make it difficult for people to find time to exercise, however this is a critical component of any mental health plan. A recent meta-analysis of 92 studies on more than 4,310 people showed that light to moderate exercise significantly reduced the incidence of depression.10 Try adding 15-20 minute walks at lunch or the end of your day to increase your activity level.

Strength training can also play a key role in mental health. Basic movements like squatting, lunging, bending, pushing, and pulling are deeply engrained in our DNA and exert tremendous positive benefit on multiple systems of the body: improving blood sugars and insulin, reducing inflammation, boosting testosterone (low levels have been associated with depression), and supporting healthy gut flora. If you’re not active, start slowly with 10-20 minutes of strength training 2-3 times weekly and focus on bodyweight type movements.

There is no “magic bullet” to fix depression. It’s a complex multi-factorial condition that is impacted by numerous systems of the body. By addressing blood sugar imbalances, weight gain, inflammation and dysbiosis, a Paleo diet can provide the body with the building blocks it needs to support positive mood.

If you suffer from depression, talk to your doctor about how you can incorporate a Paleo Diet and exercise, along with treatment into your action plan.

(This article originally appeared

 Dr. Marc Bubbs ND, CISSN, CSCS

Want to learn more? High blood sugar and insulin levels are strongly associated with depression. Listen to diabetes expert Dr. Jason Fung MD in Episode #15.


Check out more articles in the PALEO SERIES...


1. Timonen. M et al. Insulin resistance and depressive symptoms in young adult males: Findings from Finnish military conscripts. Psychosom Med 69(8):723-28.

2. Pyykkonen AJ et al. Depressive symptoms, antidepressant medication use, and insulin resistance: the PPP-Botnia Study. Diabetes Care. 2011 Dec;34(12):2545-7.

3. Felger J, Lotrich FE. Inflammatory cytokines in depression: neurobiological mechanisms and therapeutic implications. Neuroscience. 2013 Aug 29;246:199-229.

4. Emerging Risk Factors Collaboration. Diabetes mellitus, fasting glucose, and risk of cause-specific death. New England Journal Medicine, Mar 2011;364;9:328-341.

5. G. S. Hotamisligil, N. S. Shargill, and B. M. Spiegelman, “Adipose expression of tumor necrosis factor-α: direct role in obesity-linked insulin resistance,” Science, vol. 259, no. 5091, pp. 87–91, 1993.

6. Larrieu T, et al. Nutritional omega-3 modulates neuronal morphology in the prefrontal cortex along with depression-related behaviour through corticosterone secretion. Transl Psychiatry. 2014 Sep 9;4:e437.

7. Moreno-Navarrete JM et al. Circulating zonulin, a marker of intestinal permeability, is increased in association with obesity-associated insulin resistance.. PLos One 2012;7(5):e37160.

8. VanWijck K et al. Aggravation of exercise-induced intestinal injury by Ibroprofen in athletes. Med Sci Sports Exerc. 2012 Dec;44(12):2257-62.

9. Matsui H et al. The pathophysiology of non-steroidal anti-inflammatory drug (NSAID)-induced mucosal injuries in stomach and small intestine. J Clin Biochem Nutr. 2011 Mar;48(2):107-11.

10. Rebar A, et al. A Meta-Meta-Analysis of the effect of physical activity on depression and anxiety in non-clinical adult populations. Health Psychol Rev. 2015 Mar 5:1-78.

Are You Suffering From Adrenal Dysfunction?

Did you know that four out of every five visits to the doctor’s office is stress-related? In today’s 24/7 society, stressors present themselves in many different forms: mental stress from a busy work day, physical stress from an intense training session or constantly being on the run, or emotional stress from relationships with family or friends. Although stress is essential for overall health (it provides the mental and physical challenges required to stimulate positive adaptation), if you have chronic or excessive stressors or poor coping mechanisms it may result in adrenal dysfunction and/or altered cortisol rhythm.

Why Are Your Adrenals So Important To Stress?

Your adrenal glands are small triangular-shaped glands positioned on top of your kidneys that secrete specific hormones in response to stressful stimuli. The glands are made up of two parts: the inner medulla that produces the hormone adrenaline in response to stress and the outer cortex that produces cortisol. Let’s take a look at how these two hormones drive your response to stressors in your environment.

When adrenaline is produced, it triggers the breakdown of body-fat for fuel and acts by raising your blood pressure and heart rate to increase your alertness. If you enjoy a cup of coffee in the morning, you’re getting a nice little jolt of adrenaline from the caffeine that helps to increase mental focus and work capacity during exercise. This happens instantly via your sympathetic fight or flight nervous system, which is a direct connection between your brain and adrenal glands.

Whereas adrenaline preferentially catabolizes (breaks down) fat, cortisol breaks down muscle tissue to provide fuel for your body. Like adrenaline, its job is to increase your blood sugar levels to provide energy for the body to overcome the stressful event. From an evolutionary perspective, this was critical for escaping from wild animals or other threats. Nowadays, you experience a boost when you’re in the gym or training hard, but when your session is over, your stress levels should return to baseline. (If you adrenals are out of balance, this isn’t always the case and has significant negative repercussions).

Today’s Stress Response

In nature, a stressor is short-term then subsides. For example, a zebra grazing in the savannah might spot a lion in the distance resulting in a boost of adrenaline and cortisol to increase the heart rate, breath rate, and shunt blood to its working muscles should it need to run for its life! The subsequent chase might last 10-20 minutes, then it would be over and the zebra could go back to relaxing and grazing.

Thankfully, in today’s world we don’t often have to run away from lions or bears, but “modern” stressors actually exert a much more debilitating toll on our body. How is this possible?

Today, stressors last all day long! The emails don’t stop, the deadlines don’t stop, and the commitments don’t stop. Your body – and more importantly your brain – are experiencing constant and prolonged stressors, far longer than would be experienced in nature. This leads to a heavy burden on your adrenal glands and your body.

What is Adrenal Dysfunction?

While the physiological mechanisms have evolved over millions of years, the realities of sitting at a desk and having to juggle all the mental tasks from work and home life can leave your brain (and body) stuck in “fight or flight” sympathetic overdrive. For some this can manifest itself as the over-production of adrenaline and cortisol, while for others the reverse can happen and you may feel sluggish or fatigued.

In years past, clients complaining of prolonged fatigue were often diagnosed with ‘Adrenal Fatigue’, the inability of the adrenal glands to keep up with a person’s busy life or increased number of stressors. Today, we understand this is not the whole story. A new area of medicine called psycho-neuro-endocrine-immunology (now that’s a mouthful!) or PNEI is uncovering that your brain is really the root cause of adrenal dysfunction, and therefore the key player in supporting your adrenals and stress response. In short, the hypothalamus area of your brain is the master switch that tells your adrenal glands to ramp up the production of adrenaline and cortisol (over-performing adrenals), or dial it back (under-performing adrenals).

Do You Have Symptoms of Adrenal Dysfunction?

In clinical practice, I see many patients with either over-performing or under-performing adrenals. There are symptoms on each end of the spectrum that indicate adrenal dysfunction. If you have difficulty waking up in the morning, poor energy during the day, feel better after eating meals, or have diminished libido then chances are your adrenal glands are underperforming.

If you’re a person with naturally high energy levels, have high blood sugars, experience excessive sweating, have difficulty falling asleep, or feel like your mind continually races with a list of tasks and deadlines then you may be suffering from over-performing adrenals. This constant fight or flight sympathetic dominance chronically elevates cortisol levels and may lead to roadblocks in your quest for a slimmer waistline, faster 10k run time or better overall health.

There is one more piece to this complex puzzle. Your daily cortisol rhythm can also get thrown out of balance by stress. In the morning, your cortisol should be at its highest to wake you up from deep sleep and get you ready to attack the day. In the evening, your level starts to lower and should be at its lowest point at bedtime. This allows the sleep hormone melatonin to ramp up and prepares your body for deep, restorative sleep.

If you suffer from general fatigue, poor recovery from workouts, low mood, and your short-term memory is poor (e.g. you often forget what to pick for dinner, where you left your phone, or your client’s name) then poor daily cortisol rhythm may be your area of adrenal dysfunction. If you struggle to get out of bed in the morning, hit snooze multiple times, or feel desperate for a coffee to get going then chances are your morning cortisol rhythm is out of balance. If you struggle to fall asleep at night, wake up throughout the night, or classify yourself as a night owl then you likely have an altered evening cortisol rhythm.

It is important to address adrenal dysfunction and/or altered cortisol rhythm as they can lead to serious negative consequences. These include increased inflammation, poor memory, increased risk of anxiety or depression, reduced testosterone production, slow thyroid function, increased belly-fat, decreased lean muscle mass, poor blood sugar control or insulin resistance, and cognitive decline.1 If you’re not sure whether your adrenals are functioning optimally, you can request a salivary-cortisol test.2

The Adrenal Dysfunction Fix


Diet is the first place to start when correcting adrenal dysfunction. It’s critical to obtain the building blocks essential for supporting a healthy stress response. The Paleo diet is the perfect place to start.

First, increase your intake of healthy saturated fats, such as butter, ghee, or coconut oil. Studies show that fatigued and over-stressed athletes are better able to recover and maintain performance on a high fat diet, in particular when high in saturated fats.3

Next, make sure you are achieving an adequate intake of protein, as high cortisol levels will quickly break down precious muscle tissue and leave you in a catabolic state. Aim for 0.7-0.9g of protein per pound of bodyweight.

Finally, it’s not only what you add to your diet, but also what you remove. If you’re suffering from adrenal dysfunction or altered cortisol rhythm then discontinue your caffeine intake – coffee, black tea, chocolate – for 4 weeks. Sugar and caffeine cravings are classic signs of adrenal dysfunction, so be sure to eliminate all processed sugars and carbs for 4 weeks.


Busy work days or long hours in the gym can leave you burning the candle at both ends and therefore being stuck in the fight or flight sympathetic overdrive. If the root cause of adrenal dysfunction starts in the brain, it makes sense to incorporate techniques that directly impact your central command center.

Meditation is an ancient technique that helps restore your cortisol rhythm and adrenal function by stimulating your “rest and digest” parasympathetic nervous system via the vagus nerve in your brain.

Not convinced? A recent study of medical students showed that those engaging in daily mindfulness meditation practices had much lower blood cortisol levels compared to a placebo.4 Meditation has also been shown to significantly improve anxiety and depression, classic symptoms of adrenal dysfunction.5

Try this simple technique before bed to improve your “resiliency” and capacity to cope with stress:

  • Start by sitting with your eyes closed.
  • Inhale deeply through your nose; let your belly expand for three seconds
  • At the end of your inhale, hold your breath for one second.
  • Exhale deeply through your nose for another count of three seconds; let your belly draw inward toward your spine.
  • Repeat for 5-10 minutes.


Did you know that today we sleep a whopping 500 hours less each year than our grandparent’s generation? This sleep debt places a tremendous burden on our resiliency or capacity to cope with stress.

If you get less than 7 hours sleep per night, struggle to fall asleep, or wake up frequently during the night your cortisol levels will be elevated and you’ll be cutting yourself short on the recovery front.6 To support deep sleep, make sure your bedroom is set up for optimal recovery. How can you improve your sleep quality? Here are some simple tips:

  • Turn down the lights in your house after 9 p.m.
  • Shut off your television or laptop at least 45 minutes before bed.
  • Make sure your bedroom is completely dark. Try using blackout blinds or an eye mask to prevent unwanted light.
  • Keep your bedroom cool and wear loose-fitting clothing or sleep naked

We’ve got a in-depth article on how to get better sleep if you want to know more.

Nutrient Support

There are several herbs that can support adrenal dysfunction, depending on whether you suffer from over-active or under-active adrenals, or cortisol rhythm dysfunction. A key nutrient called alpha-GPC can benefit all types of adrenal dysfunction. Supplementing with alpha-GPC provides the hippocampus with the right building blocks to restore normal cortisol rhythm by supporting the production of acetylcholine, a key neurotransmitter concentrated in the hippocampus that can be depleted by busy work schedules, lacking sleep or high stress.7 Take 500-1,000mg daily upon rising for 8-12 weeks.

Prioritize the fundamentals of diet, sleep, and controlling your stress response (e.g. proper breathing) to upgrade your adrenal function and correct symptoms of adrenal dysfunction. Train your brain and fuel your body correctly to increase your resiliency and keep your stress response system in balance.

Dr. Marc Bubbs ND, CISSN, CSCS

Want to learn more? Listen to Dr. Doug Kechijian talk "Mental Performance In High Stress Situations" on the Dr. Bubbs Performance Podcast...


Check out more articles in the "Cortisol Stress" Series...



Reynolds G. The Hormone Edge. J of Physio. NY Jan 14, 2012.
Manetti L et al. Usefulness of salivary cortisol in the diagnosis of hypercortisolism:comparison with serum and urinary cortisol. 2013. Eur J Endocrinol 168(3):315-21
Antonio, J et al. Essentials of Sports Nutrition and Supplements. Humana Press. New York, NY.
Turakitwanakan W et al. Effects of mindfulness meditation on serum cortisol of medical students. J Med Assoc Thai 2013 Jan;96 Suppl 1:S90-5.
Wurtzen H et al. Mindfulness significantly reduces self-reported levels of anxiety and depression: results of a randomised controlled trial among 336 Danish women treated for stage I-III breast cancer. Eur J Cancer 2013 Apr;49(6):1365-73.
Leproult R, Copinschi G, Buxton O, et al. Sleep loss results in an elevation of cortisol levels the next evening, Sleep. 1997;20:865-870.
DiPerri R. et al. A multicenter trial to evaluate the efficacy and tolerability of alpha-glycerylphosphorylcholine versus cytosine diphosphocholine in patients with vascular dementia. J Int Med Res. 1991. Jul-Aug;19(4):330-41.