Higher Calcium Intake Increases Risk of Heart Disease and Early Death
Coming on the heels of a large 2012 study indicating calcium risk, two recent studies have found that calcium-heavy diets and calcium supplementation may increase the risk of heart disease and early death.
The newest study, published in the British Medical Journal Lancet, comes from Sweden’s Uppsala University. For 19 years, the researchers followed 61,433 post-menopausal to elderly Swedish women – born from 1914 to 1948.
The researchers tracked their dietary calcium intake along with their calcium supplementation while tracking their incidence of cardiovascular disease, ischemic heart disease and strokes, along with deaths from all causes.
The researchers found that when compared to those who had diets with 600-1000 milligrams of calcium per day (non-supplemented), those whose diets contained at or above 1400 milligrams per day of dietary calcium had more than double the incidence of dying from ischemic heart disease and almost 50% increased incidence of dying from cardiovascular disease. Strokes, however, were 27% lower among 1400 mg calcium or more eaters.
This study follows another recent study on calcium, published in the Archives of Internal of Medicine. In this study, 388,229 Americans between 50 and 71 years old were followed for an average of 12 years, and tracked for their calcium supplementation use. Calcium supplements were used by 51% of the men and 70% of the women in this study.
The researchers found that those men who took more than 1000 milligrams of supplemental calcium a day had a 20% increased risk of dying from heart disease and a 14% increased incidence of cerebrovascular death (stroke).
However, women did not have the same level of increased risk in this study. Heart disease deaths only increased 5%-6% and death from strokes only increased 8% among women.
Another study, however illustrated that both men and women suffered from increased calcium supplementation. Research published in 2012 from the German Cancer Research Center followed 23,980 men and women who were between 35-64 years old who were healthy at the beginning of the study. The subjects were followed up for an average of 11 years while their calcium supplement intake was tracked.
As compared with those who did not supplement with calcium, those who took calcium supplements had an 86% increased incidence of having a heart attack. Furthermore, those whose calcium intake was primarily via supplements had more than double the increased risk of having a heart attack when compared to those who did not take calcium supplements.
In this study, however, those whose dietary-only calcium intake was higher had a 31% decreased risk of heart attack incidence.
Certainly the results are not consistent among all three studies, but each of the studies had slightly different protocols and population groups, ranging from Europeans (Swedes and Germans) to American subjects. These populations tend to have slightly different dietary habits, but each population eats a predominantly western diet.
Other studies have shown that the western diet is a diet with considerably more risk of heart disease when compared to an Asian diet or the Mediterranean diet. How does this affect the risk of heart disease? Studies of these diets have shown that those diets with high levels of saturated animal fats tend to have greater incidence of heart disease. This has been proven by multiple studies of large population groups around the world.
The most recent is a study showing the effects of the Mediterranean diet was just published from researchers at the University of Rome’s School of Medicine. In this study, 80 people with metabolic disease – inclusive of cardiovascular disease – were treated by being put on an Italian Mediterranean Diet. After six months, metabolic syndrome was resolved in 52% of the patients.
As for supplemented calcium, all three calcium studies are showing an increased risk of death and/or heart disease deaths from higher supplemented calcium use. While the relationship between calcium and the rest of the diet is not examined in any of these studies, one can assume that those who have a largely western diet containing more foods that contain saturated fats and calcium will also have a greater risk of heart disease and deaths if they add additional calcium.
This relationship between the western diet and calcium intake is evidenced in a study from France’s University of Bordeaux Segalen, published in late 2012. This study followed 1,595 French persons. The study found that those who adhered to the Mediterranean diet had lower intakes of calcium, especially among the women. The Med diet adherence also resulted in significantly lower intakes of saturated fats.
This indicates that supplemented calcium in itself may or may not increase the risk of heart disease, but certainly, supplemented calcium within a western diet of increased saturated fats increases the risk of death and/or heart disease.
While nutritional studies often myopically hone in on a particular nutrient or supplement, we must not lose the big picture. Our body’s health is a product of lifestyle, diet and supplement use combined. Dietary supplements taken without the balance that nature provides in a healthy diet – with plenty of plant-based nutrients – can lead to precisely the opposite result intended when considering nutritional supplements in the first place.
Written by Case Adams, Naturopath
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