How Can Sunscreen Cause Alzheimer’s?

By Dr. Mercola

Alzheimer’s disease is currently at epidemic proportions, with 5.4 million Americans — including one in eight people aged 65 and over — living with Alzheimer’s disease, according to the Alzheimer’s Association’s 2011 Alzheimer’s Disease Facts and Figuresⁱ.

By 2050, this is expected to jump to 16 million, and in the next 20 years it is projected that Alzheimer’s will affect one in four Americans.

You do not, however, have to feel powerless against this disease, as although there is no known cure as of yet, there are simple strategies available to significantly lower your risk.

The Alzheimer’s Risk Factor You Probably Haven’t Heard Of …

Do you heed the advice of public health officials who advise putting on sunscreen every time you go out in the sun?

This could very well be raising your risk of Alzheimer’s disease because it blocks not only your body’s ability to produce vitamin D, but also your production of cholesterol sulfate.

Unfortunately most of you reading this have probably only heard of cholesterol referred to in a negative way, but actually adequate cholesterol is essential for good health.

For example, 25 percent of the cholesterol in your body is in your brain, even though your brain is only 2 percent of your body’s weight. The cholesterol is absolutely essential for neuron transport, which is why lack of cholesterol can negatively affect your brain function. But impaired memory and dementia are just the tip of the iceberg when it comes to low cholesterol’s impact on your brain. Having too little of this beneficial compound also:

Increases your risk of depression
Can cause you to commit suicide
May lead to violent behavior and aggression
Increase your risk of cancer and Parkinson’s disease

That’s a bit of background to get you warmed up to the idea that cholesterol is your friend, not your enemy. Now, getting back to sunscreen and Alzheimer’s, using these products will make it virtually impossible for your body to do what it was designed to do, which is produce important, disease-fighting substances like vitamin D and cholesterol sulfate when exposed to the sun. Dr. Stephanie Seneffⁱⁱ, a senior scientist at MIT who has a wealth of information about the importance of sulfur, explains:

” … depletion of sulfate supply to the brain is another important contributor to Alzheimer’s, and I further think that sulfate is supplied to the brain principally by sterol sulfates like cholesterol sulfate as well as their derivatives like vitamin D3 sulfate. Both cholesterol sulfate and vitamin D3 sulfate are synthesized in the skin upon exposure to sunlight, and it is theorized that the skin is the major supplier of these nutrients to the body. This is why I believe that excess sunscreen use and excess sun avoidance are another principal causative factor in Alzheimer’s disease.”

Why is Cholesterol Sulfate so Important?

Your skin produces large amounts of cholesterol sulfate, which is water-soluble and provides a healthy barrier against bacteria and other potentially disease-causing pathogens that might otherwise enter your body through your skin. And, due to its polarity, it can enter both fat cells and muscle cells with equal ease. Dr. Seneff proposes that, because of this, cholesterol sulfate may be able to protect fat and muscle cells from glucose and oxygen damage.

She also argues that when you’re deficient in cholesterol sulfate, your muscle and fat cells become more prone to damage, which subsequently can lead to glucose intolerance, a condition where your muscles cannot process glucose as a fuel. As a result, your fat cells have to store more fat in order to supply fuel to your muscles, and excess fat accumulates as damage increases.

Sulfur also plays an important role in glucose metabolism. She hypothesizesⁱⁱⁱ that if a sufficient amount of sulfur is available, it will act as a decoy to glucose, effectively diverting it to reduce the sulfur rather than glycating and causing damage. This would have the beneficial effect of reducing inflammation, as sugar (glucose) is highly inflammatory and wreaks havoc in your body.

What does this have to do with your brain? The process applies not only to fat and muscle cells, but also to cells in your brain (and, in fact, to all cells in your body). Dr. Seneff explains:

“Essentially all cells in the body are surrounded by an exterior coat made up of complex molecules called “GAGs” — glycosaminoglycans. These contain sugars, proteins, and a large population of attached ions, particularly sulfate anions. These serve, I believe, an important role in helping to safely break down sugar. Simply stated, the sulfur atom deflects the reducing actions of sugars away from the vulnerable proteins.

The sulfate anions also provide a negative field around the cell, which is very useful for keeping bacteria out, because bacteria are also negatively charged, and hence repelled by the cell’s negative electric field. So cells with lots of surrounding sulfate are afforded protection from invasive bacteria. If a bacterium does get in, the cell will have to release oxidizing agents to kill it, and the cell itself will suffer damage from exposure to its own defense system. The fats in the cell membrane are more vulnerable to oxidative damage when there is insufficient cholesterol to protect them.”

This means that depletion of the sulfate supply to your brain could leave your brain cells more susceptible to damage and may increase your risk of Alzheimer’s disease. Dr. Seneff also points out to recent papers that have also linked insufficient cholesterol with Alzheimer’s and mental decline:

Serum levels of cholesterol as well as the ability to synthesize cholesterol are inversely associated with mental decline^iv in the elderly
A study directly comparing Alzheimer’s patients with age-matched controls showed a reduced serum level of LDL in the Alzheimer’s patients^v, with the more severe cases showing further reduction in LDL

Vitamin D Deficiency Also Increase Alzheimer’s Risk

Sunscreen is a double-edged sword when it comes to your brain health, as aside from blocking your ability to produce cholesterol sulfate, it also blocks your production of vitamin D — and there is no shortage of research linking vitamin D to brain health. One such study was actually launched after family members of Alzheimer’s patients who were treated with large doses of prescription vitamin D reported they were acting and performing better than before.

Strong links between low levels of vitamin D in Alzheimer’s patients^vi and poor outcomes on cognitive tests were revealed. Researchers believe that optimal vitamin D levels may enhance the amount of important chemicals in your brain and protect brain cells. Vitamin D may also exert some of its beneficial effects on Alzheimer’s through its anti-inflammatory and immune-boosting properties. Sufficient vitamin D is imperative for proper functioning of your immune system to combat inflammation that is also associated with Alzheimer’s.

Safe Sun Exposure Without Sunscreen

If you work outdoors all day as part of your job, or if you need to protect sensitive areas of your face, like around your eyes, that are particularly susceptible to photoaging and not large enough a surface to impact vitamin D levels if blocked with sunscreen, certain sunscreens available in most health food stores, and my Healthy Skin Sunscreen, are safe to use when the need arises. However, I personally use and recommend wearing a hat when you are in the sun as this typically can shade the sensitive skin around your eyes.

I would avoid applying sunscreen regularly as most commercial ones have toxic chemicals that you should not be exposed to. If you do use a sunscreen make sure it is safe and natural.