For years I have written on the dietary salt myth*. In a nutshell, it seems taken as conventional wisdom and irrefutable scientific fact that reductions in dietary sodium lead to significant reductions in blood pressure and improvement in cardiovascular mortality and morbidity from things like heart attacks and strokes. Yet despite almost 50 years of scientific study, over 150 randomized controlled trials and 13 population-based studies, the conclusive data is still lacking. Confounding the results of some of these trials was the fact that the consumption of foods that help lower blood pressure were never taken into account in the final analysis.
What are some of these foods?
It turns out that foods that are rich in potassium have a positive effect on lowering blood pressure and potentially reducing cardiovascular morbidity and mortality. These foods include fresh vegetables like Swiss chard, potatoes, yams, acorn and other winter squash, lentils, peas, lima beans, pinto and kidney beans. It includes fresh fruits like papaya, dried apricots, avocados and bananas-although they are not the ultimate source of potassium, per serving, as most people think. Fresh dairy products like yogurt and items like Portobello or crimini mushrooms are also good sources. Fish like salmon, pompano, halibut, tuna and anchovies likewise deliver good amounts of potassium. Herbs like basil and spices like turmeric are also good sources, although these are not usually consumed in significant quantities compared to other foodstuffs.
Further complicating the picture is the fact that in addition to foods rich in potassium, foods rich in both calcium and magnesium have also been shown to help reduce blood pressure. Foods rich in calcium include dairy such as yogurt, goat’s milk, cow’s milk and cheese. It includes fish such as sardines. Vegetable sources include tofu, greens like collard greens and turnip greens, spinach and food products containing sesame seeds like tahini (a major ingredient in hummus). Foods rich in magnesium include vegetables like Swiss chard, spinach, soybeans, black beans, pumpkin seeds, sesame seeds, sunflower seeds and nuts like cashews, almonds and pine nuts. Fish like halibut and mackerel are also a great source of magnesium as are whole grains like brown rice and quinoa.
To completely muddy the waters, a recent study presented at the European Society of Human Genetics meeting in Paris**suggested a significant potentially causal association between low vitamin D levels and the development of hypertension. Humans can produce vitamin D through exposure to sunlight. Foods rich in vitamin D include fish like salmon and sardines and other foods like mushrooms. Milk from grass fed, pasture raised goats and cows and eggs; especially eggs from vegetarian fed, organic, free range chickens.
Interestingly, additional supplementation with minerals, whether it be potassium, magnesium or calcium do not share the positive effects observed with a diet rich in these components. Furthermore, the highly processed versions of these foodstuffs often results in a significant alteration of their natural structure. For example, foods that are naturally rich in potassium and have lower amounts of sodium often wind up after processing with much higher levels of sodium and significant reductions in the potassium content. In fact the bulk of dietary sodium intake, over 70%, comes from the consumption of highly processed, prepared and preserved foods. The clear take away from all this information is to follow a simple three-step approach:
- 1. Avoid the consumption of excessive amounts of fast food, which includes many sit down and dine type chain restaurants.
- 2. When shopping for foods in the market, avoid ready-made highly processed and preserved foods.
- 3. Whenever possible look for the fresh minimally adulterated product; this often means being aware of what is locally and regionally available in any given season.
By following these 3 simple steps, you are on your way to becoming a Grassroots Gourmet™; and that’s the prescription for eating well and living better.
*Read Dr. Mike’s latest article on the salt controversy published in Pacific Standard magazine here:
**Santhanakrishnan VK, et al "A causal association between vitamin D status and blood pressure: a Mendelian randomization study in up to 150,846 individuals" ESHG 2013; Abstract #C18.2.