Low sodium intake is associated with heart disease

A recent study in Canada examined the sodium and potassium intake of 28,800 participants in two large studies spanning a seven year period. They measures average excretion rates which is one way to determine intake as noted by a fairly high accuracy rate from this study.

The healthiest sodium intake was between 4 to 6 grams. Those who consumed lower or much higher amounts had higher incidence of death from heart attacks and strokes. I have not seen any randomized studies providing definitive proof that a low sodium diet reduces heart attack and stroke rates. The current science seems to indicate a moderate intake of sodium for improved cardiovascular health is best.

This is in stark contrast with current government recommendations which are as follows:

  • AI (adequate intake) is 1.5 grams
  • Maximum intake is 2.3 grams

Both of these government recommended daily allowance references place the public at increased risk for heart attack and stroke. No wonder cardiovascular disease is the per-eminent killer in America just behind iatrogenic causes. Reducing sodium too much is dangerous and ineffective for controlling blood pressure as demonstrated by this metaanalysis due to increased renin secretion (raising blood pressure) and sodium depletion (which causes a sympathetic response). The study also showed that moderate sodium intake of 4.6 grams (within a healthy range) did have a positive impact on blood pressure.

This, in addition to other factors may be why sodium intake higher than government guidelines is good for you. Sodium has many roles in our body. Perhaps the most well known is the sodium potassium pump (SPP). This is what helps maintain our blood pressure and contractility. Every muscle is dependent upon proper function of the SPP in order to work effectively, especially your heart.

We shouldn’t be afraid of sodium. We should be afraid of the processed foods that abuse sodium placing us at risk. Eating a healthy diet composes of whole, unprocessed foods and flavoring to taste with healthier versions of salt (like Himalayan or sea salt) and other healthy spices like cumin, cayenne, curry, and cinnamon are much wiser choices.

Low Total Cholesterol and Mortality Rates

This is an exploration of mortality rates associated with low cholesterol. The review was published in Circulation: Journal of the American Heart Association. In this review, the National Heart, Lung, and Blood Institute held a conference seeking to understand why lower total cholesterol (TC) levels are associated with some cancers, respiratory and digestive diseases, trauma, and residual deaths.

Apparently, men are more susceptible to this correlation than women. They examined 19 cohort studies from the U.S., Europe, Israel, and Japan. TC is a calculation of cholesterol measurements of LDL, HDL, and triglycerides.  The review noted high rates of cerebral hemorrhage with lower average TC. The rate of cerebral hemorrhage decreased as average TC went up in prospective populations. This was true in the Multiple Risk Factor Intervention Trial (MRFIT) in addition to increased incidence of colon cancer with lower TC. This may be related to what I wrote in an earlier post.

For women, 6 of the 11 studies showed no variation in cancer death rates across all spectrum of TC levels. There was an increased cancer risk in men when their TC levels fell below 180 mg/dL. In non-cancer and non-cardiovascular death rates, both men and women had similar risk findings. When TC was below 160 mg/dL there was a 40% increase of mortality compared to 160-199 mg/dL levels. Risk was also reduced by 10% when TC levels were between 200-240 mg/dL compared to the reference class (TC between 160-199 mg/dL levels).

This increase in non-cardiovascular deaths raises the issue of the dangers associated with taking cholesterol lowering drugs. These dangers are real and should not be taken likely (as mentioned in the study). Once again, when the data was pooled together, TC below 160 mg/dL was associated with highest risk of mortality.

Unfortunately, some of the data did not differentiate between age or sex but we can assume that having TC this low for anyone is quite risky. The review did take into account people with diabetes, smokers, CVD, alcohol intake, and other possible factors that might skew the data. Some of the research also separated participants further by age and gender.

Findings for all-cause mortality (ACM [death from any cause]) for those with TC between 200-240 mg/dL had the lowest incidence. The rate of death increased the TC went down below 199 mg/dL (are you seeing a trend yet?). Interestingly enough, the American Heart Association, the journal’s parent organization, say that total cholesterol should be below 200 mg/dL. This is the range that has been demonstrated by the AHA to increase risk death from all causes. The standard protocol for primary care providers is to prescribe statin medication when TC is above 200 mg/dL which will place patients well within the range of increased risk of death. 

There are also other health risks associated with direct effect of statin use in addition to health benefits not associated with TC lowering mechanisms. Statins act on many mechanisms in addition to reducing cholesterol synthesis in the liver. A benefit-risk analysis of statin use will be explored in a future post.

It is safe to say that total cholesterol levels appear safest when they remain in the range between 200-240 mg/dL. This is my target. Unless you have a very rare disease, it is completely controllable through diet which will be discussed later. Don’t forget exercise will increase your total cholesterol level (by increasing HDL) as it improves your health.