Recently there has been a lot of press about the role of salt, or sodium, as a risk factor for the development cardiovascular disease and subsequent events. A recent meta-analysis looked at salt intake and found that higher levels of salt intake were associated with a modest increase in blood pressure. This increase did lead to an increase in the absolute number of cardiovascular events, but this did not reach statistical significance. This follows on the heels of another study that examined normotensive (those without hypertension) individuals and found that the highest mortality risk was in the group with the lowest sodium intake, as measured by sodium excretion. These findings have reignited the debate of the role of sodium in the development of heart disease and levels of appropriate sodium intake; even as the new guidelines call for the consumption of lower amounts.
What do we know? The data seem clear that increasing levels of salt, or sodium, are associated with increases in blood pressure and contributes to or worsens hypertension. Hypertension is a risk factor for the development of cardiovascular disease and a potent risk factor for stroke risk. Treating underlying hypertension has been demonstrated to reduce both cardiovascular and stroke risk. The operative hypothesis to this point has been that the communicative property applies here: that reducing salt intake would reduce the blood pressure and thus translate into a reduction in cardiovascular risk. Unfortunately, as Dr. Yusuf, DPhil from McMaster University and a cardiovascular expert on meta-analysis notes the direct evidence linking high dietary salt consumption and cardiovascular disease is “weak and inconsistent.” We also know that in the body, sodium exists in a ratio related balance with potassium. Potassium is another element necessary for proper bodily functioning and is especially important from a cardiovascular perspective.
A recent study published in the Archives of Internal Medicine sheds some new light into the reason why we have seen these apparently contradictory results (Yang, Liu, & Kuklina, 2011). As one of the study investigators, Dr. Kuklina, notes, “This is the first large, nationwide study where we followed a pretty big cohort of people and looked at sodium and potassium at the same time.” The examined over 12,000 people for all cause and cardiovascular risk as part of the Third National Health and Nutritional Examination Survey (NHANES III). What they found over a 15 year period was that the highest risk group had a very high ratio of sodium to potassium in their diet. Previous analytic concentration focusing on only half the equation would explain the dichotomous findings over the years. As sodium increased, risk increased about 20% for every 1000mg/day. However, for every 1000mg/day increase in potassium, the risk decreased about 20%. Thus, based on these findings what is of paramount import is maintaining a sodium/potassium ratio less than 1.
What does this mean? It means even more evidence to be following our Grassroots Gourmet™ principles. Firstly, Fast/Junk food is often loaded with sodium, which is why we strive to be aware and avoid the call of the junk food fast food siren. Second we want to be fresh-but no adultery! Over 75% of our intake of sodium each day is derived from pre-packaged, processed and prepared food. When using sodium to season and create a perfectly balanced and delicious meal, we add only about 5% of what is our daily intake. Not only that, but processing adulterates and alters the composition of our food in a potentially detrimental way. As noted by the study authors, a 100g (about 3 ½ ounces) serving of natural wholesome fresh pork contains roughly 60 mg of sodium and about 340mg of potassium. But if you industrially process that into the average deli ham you end up with 920mg of sodium and only 240mg of potassium. Avoiding fast food and preprocessed adulterated food will help reduce sodium intake. Consuming foods rich in potassium such as fruit (apricots, bananas, avocados, tomatoes, cantaloupes and oranges for example), vegetables (like beets, brussel sprouts, lima beans, winter squash, potatoes and spinach) and legumes like peanuts as well as yogurt will contribute to increasing potassium intake. As with all things in Nature, it’s about the balance.