What do heart attacks, high blood pressure, rheumatoid arthritis and asthma have in common?
I had the pleasure of going to the 2019 International Conference of Nutrition in Medicine sponsored by George Washington University and the Physicians Committee for Responsible Medicine. This year’s speakers included researchers from Harvard, Yale and Brown, as well as Dr. Ostfeld from my alma mater, Albert Einstein College of Medicine in New York.
The initial lecture was by Paul Ridker, M.D., MPH, Director of the Center for Cardiovascular Disease Prevention Divisions of Cardiovascular Medicine and Preventive Medicine Brigham and Women’s Hospital and Professor at Harvard Medical School. He started with a dramatic slide of a large blood vessel filled with plaque next to a hand with severe rheumatoid arthritis changes. He spoke about how seemingly disparate diseases are linked in a very fundamental way. Our bodies produce an inflammatory response for many reasons – based on cholesterol crystals, our own body’s proteins, as in these examples, or a multitude of other entities – and that response can then cause damage in blood vessels, joints, etc. The damage that it causes in blood vessels can lead to heart attacks, strokes, and peripheral vascular disease.
One of the ways to measure the level of inflammation in our bodies is by C-reactive protein (CRP). A high level is very nonspecific. It can arise from fighting an infection as well as any of the reactions mentioned above. The traditional CRP measures levels above 3, but the high sensitivity CRP (hsCRP) can measure more accurately to less than 1, and is more helpful when we discuss risk of heart disease.
We see high levels in people at risk for cardiac disease, and the higher the level, the more likely the person can have a heart attack or stroke in the years to come. I’m not suggesting that the high level of CRP causes those events, just that it is associated with it – it indicates that there is underlying inflammation, which may be the cause of the event. Closely associated is the level of interleukin 6 (IL6), which is a chemical released by our cells that induces more inflammation.
You are probably familiar with the ‘traditional’ risk factors for heart attacks and strokes, such as high blood pressure, high cholesterol, diabetes, smoking, obesity. Whether you look at a population that has these risk factors or not, within each risk group, those with the higher level of hsCRP and IL6 are more likely to run into health problems.
If you have any of the risk factors for heart disease, your doctor may have you on medications for high blood pressure and high cholesterol, and advised you to lose weight and stop smoking. A common class of medications we use, the statins (think atorvastatin, rosuvastatin and others, with brand names of Lipitor and Crestor) lower cholesterol, but are also anti-inflammatory. They lower hsCRP and IL6. For years we have looked at the benefit of lowering total cholesterol or LDL (bad) cholesterol, or raising HDL (good) cholesterol. Now, we also look at non-HDL as being an important number – the total minus the HDL. What wasn’t recognized initially is that it may be more important that we lower the hsCRP and IL6 than whether we lower the cholesterol level. The statins do both.
Other cholesterol-lowering meds that are not anti-inflammatory can lower cholesterol tremendously, without affecting the rate of heart attacks or strokes as much.
The best news is that in the NIH Pounds Lost Trial, dark chocolate lowered CRP – a good reason to eat more of it 😉
We’ve learned that the level of inflammation is critical. In fact, the 2008 JUPITER trial looked at 17,000 patients whose cholesterol was NOT high, but their CRP was elevated above 2. Those treated with statins did remarkably better than those not treated. There was a 44% decrease in first heart attack, stroke or death. It is unclear so far whether a high CRP due to RA or lupus puts people at any higher risk for cardiac disease. But in the general population, in those without known cardiac disease, the baseline CRP does predict longterm risk of 1st heart attack or stroke, high blood pressure, peripheral vascular disease and death from all causes.
Studies have been looking at the incidence of cancers and heart attacks in patients who are given anti-inflammatory agents to alter their rheumatoid arthritis (CANTOS trial, 2017). It turns out that the situation is similar. Using an anti-inflammatory agent that is meant for RA treatment, cholesterol did not change, but CRP and IL6 decreased significantly, and there was a 15% reduction in major cardiovascular events. An unexpected finding was that there was a 70% decrease in lung cancer over the following 5 years in those whose CRP and IL6 levels fell below the median. In retrospect, this positive change was felt to be related to reducing the inflammation in the area of the tumor. This latter finding will have to be explored further in other studies. In other studies with anti-inflammatory agents, there was a decrease in gout and the need for joint replacements.
As if on cue, a New England Journal of Medicine article published last week detailed how the severity of asthma and high blood pressure in an individual is also linked to inflammation as measured by CRP and IL6. The inflammatory chemicals increase and tighten the smooth muscle cells in the airways and in the blood vessels, worsening both illnesses. Looks like inflammation is bad all around!
So all this information is only useful if we can use it to our benefit. How can we decrease the inflammation in our bodies?
Statins are one path. We also gain power through good nutrition, exercise and not smoking. A vegan diet, (no animal products at all) decreases the risk of events by 32%. This is better than our often-touted Mediterranean diet, but there are huge overlaps, including fruits, vegetables, whole grains, nuts and seed.
Importantly, in many of the talks, it was stressed not to let perfect be the enemy of good. If the majority of people can shift their diet to more plant based – even if not exclusively plant-based – it would be better than people not changing because they feel they can’t be successful at a completely plant-based diet. For the good of the environment and our bodies, avoid eating cows. Decrease poultry and fish to a level that’s sustainable for you. Dr. Ridker also suggested adding sneakers to the base of the food pyramid – to use, not to eat, of course – with a flight of stairs leading to the top of it.
Screening in the general population with CRP levels has been controversial for years, and still is. Last year’s statement from the U.S. Preventive Services Task Force still states that there is not enough data to support its use.
Do the best you can with diet and exercise to reduce inflammation – the same recommendations we’ve been supporting for years! It’s good for your heart, your brain, your longevity – can’t beat it!
- Ridker, Paul. Presentation 7/25/19 at International Conference on Nutrition in Medicine.
- Christiansen, S and Zuraw, B, Treatment of Hypertension in Patients with Asthma, NEJM 2019; 381:1046-57.
- UpToDate 2019: CRP in cardiovascular disease
- How to increase the grains in your diet
- The healthy path to your heart is through your stomach – about Mediterranean style diet with links to recipes