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I like to eat two eggs sunny side up, with hash brown potatoes, rye toast, and a double espresso for breakfast sometimes. Those breakfasts may soon be a just a memory. A new study indicates I may have to substitute egg whites for those sunny siders.
According to a report of almost 30,000 U.S. adults (45 percent men; 31 percent black) collected from six prospective cohort studies and followed for 17.5 years, each additional 300 mg of dietary cholesterol consumed per day (about 187 mg cholesterol makes up a large egg) increased the risk of cardiovascular disease (CVD) and death, by 17 percent and 18 percent, respectively. Each additional half an egg consumed per day increased the risk in a dose dependent fashion. The conclusion was that eating eggs for breakfast was associated with higher risk of cardiovascular disease and death.
Other studies support these conclusions. For example, the Nurses’ Health Study included 73,710 women from 1984 to 2012 and 92,329 women from 1991 to 2013; while the Health Professionals Follow-up Study from 1986 to 2012 included 43,259 men. None had chronic diseases to start. The authors found in over 4,833,042 person-years of follow-up that higher intake of a plant-based diet rich in healthier plant foods (like whole grains, fruits/vegetables, nuts/legumes, oils, tea/coffee) was associated with substantially lower coronary heart disease (CHD) risk, whereas a diet that emphasized animal-derived foods was associated with higher CHD risk.
One can question the results of such observational studies for several confounding reasons, including the accuracy of reporting food intake, knowing people have fallible memories and might exaggerate or underestimate intake of certain foods. However, we now have a potential explanation why plant-based diets are beneficial: reduced inflammation.
Recent studies have firmly established the role of inflammation in promoting coronary artery disease (CAD), and that reducing such inflammation can reduce cardiovascular mortality by almost a third.
It turns out that a diet emphasizing plant-based foods reduces inflammation. Researchers randomized patients with CAD to eight weeks of a vegan diet compared with those randomized to an American Heart Association-recommended diet. The two diets differed by the absence of animal protein in the vegan diet. They found that a marker of inflammation was 1/3 lower in those on the vegan diet compared to the AHA diet, with no difference in body mass index, waist circumference or glycemic control. So the vegan diet reduces inflammation, which would be expected to reduce CAD.
The Mediterranean Diet (MD) also reduces inflammation. In a recent study, baseline MD was assessed in 25,994 initially healthy U.S. women in the Women’s Health Study who were followed up to 12 years. The investigators found that a higher MD intake was associated with approximately one-fourth relative risk reduction in cardiovascular (CV) events. The largest mediators of the CV risk reduction from MD intake were biomarkers of inflammation (accounting for 29.2 percent of the MD-CVD association), glucose metabolism and insulin resistance (27.9 percent), and body mass index (27.3 percent).
The MD can be made more “potent” by supplementing it with nuts or extra-virgin olive oil. In a multicenter trial in Spain, investigators assigned 7447 participants (55 to 80 years of age, 57 percent women) who were at high CV risk, but with no CV disease at enrollment, to one of three diets: a MD supplemented with extra-virgin olive oil, a MD supplemented with mixed nuts, or a control diet (reduced dietary fat). They found that the incidence of major CV events was lower among those assigned to a MD supplemented with extra-virgin olive oil or nuts than among those assigned to a reduced-fat diet.
Sadly, I guess I will have to do without my sunny siders in the future. Maybe if I cook them with extra-virgin olive oil and eat some walnuts on the side I can mitigate the harm. After all, as I’ve said before, moderation in all things, including moderation.