Most people are aware that hypertension (high blood pressure) is a major risk factor for cardiovascular disease. However, few realize that hypertension is also a primary cause of kidney disease. Since the most recent estimates indicate that over 50 million Americans now have hypertension, protecting the kidneys from high blood pressure’s consequences is more important than ever. Based on some research, adhering to an anti-inflammatory eating plan could be the key to preserving kidney function in the extremely prevalent hypertensive population.
Hypertension and the Kidneys
The kidneys are intimately connected to blood pressure regulation and elevation. The relationship between hypertension and kidney disease has been likened to the chicken and the egg puzzle; because it’s hard to determine which came first:
- For some people, hypertension is the main cause of their kidney disease. Hypertension can cause damage to the blood vessels and filters in the kidney, thus contributing to kidney disease. The glomeruli are tiny, fragile, filtering structures in the kidney that are frequently damaged when blood pressure remains too high.
- For others, kidney disease came first and caused an increase in their blood pressure. If the kidneys are damaged, they are less able to control the body’s fluid balance, which can increase blood pressure.
To prevent hypertension from injuring the kidneys, managing blood pressure is a top priority. Keeping blood pressure within a normal range is typically achieved by adopting lifestyle changes and/or using blood pressure lowering drugs. Though, researchers from the Medical College of Georgia have made a discovery that could have significant potential to help the kidneys of those with hypertension.
As published in a May 2010 issue of American Journal of Physiology – Renal Physiology, researchers found that treating hypertensive rats with a broad-acting anti-inflammatory drug helped their kidney function. More specifically, an anti-inflammatory drug helped preserve the kidney’s ability to regulate pressure placed on the glomeruli.
Dr. Edward W. Inscho, corresponding author and physiologist in the MCG Schools of Graduate Studies and Medicine explains that it is desirable for the kidney’s vasculature to constrict when blood pressure rises because:
- It protects the kidney’s delicate filters.
- It helps the kidneys keep blood flow and filtration relatively constant.
Inscho’s animal studies have shown that this ability to constrict, known as mechanosensor function, falters after just three days of high blood pressure. Even slightly elevated pressures resulting from too much salt consumption can render the mechanosensors less responsive.
The exciting news is that this research demonstrated that regular anti-inflammatory therapy appears to help the kidneys retain their ability to sense pressure change and respond appropriately. Despite this breakthrough, Inscho concedes that this exact approach isn’t a recommended treatment option because of the side effects that can result from long-term use of anti-inflammatory drugs. Luckily, there is a non-pharmaceutical, anti-inflammation strategy that holistic medical practitioners have advocated for years: an anti-inflammatory diet.
Different from other restrictive eating plans, an anti-inflammatory diet is not a diet per se. Rather, it is a way of selecting and preparing foods based on scientific knowledge that helps minimize inflammation in the body. The medical community is increasingly realizing that chronic inflammation plays a role in many types of illness. Chronic inflammation disrupts the immune system and typically results in damage to healthy tissue. Although a wide range of factors can promote inflammation, poor diet appears to be a major contributor.
Appearing to be very simplistic, most eating patterns can be altered to follow these four anti-inflammatory diet principles:
- Variety – Strive to consume a wide variety of foods.
- Fresh – Include as much fresh food in your diet as possible.
- Produce – Make fruits and vegetables the cornerstone of snacks and meals. Choose produce from all parts of the color spectrum – especially berries, tomatoes, orange and yellow fruits, and dark leafy greens.
- Avoid Inflammatory Foods – Keep consumption of foods that fuel inflammation to an absolute minimum. Such foods include processed food, junk food, fast food, high-fat meat and sugar (including high fructose corn syrup). In addition, foods that contain arachidonic acid (usually comes from dietary animal sources – meat, eggs and dairy) worsen inflammation.
By acknowledging the principles of an anti-inflammatory diet, individuals with hypertension can indirectly protect their kidneys. Research has yet to be done on how an anti-inflammatory diet can protect the kidneys from hypertension, but based on Inscho’s research, such a study is anticipated soon. Because an anti-inflammatory drug influences the kidney’s mechanoreceptors to adjust and protect the glomeruli, there is every reason to believe that an anti-inflammatory diet will exert a similar type of effect.