Many biochemistry factors contribute to the “neurodegeneration” that leads to Alzheimer’s disease. These include brain inflammation…high levels of insulin in the brain, triggered by high blood sugar…nutritional deficiencies…and poor breakdown and elimination of the waste products generated by normal brain activity.

The four supplements I recommend work together to balance brain biochemistry, thereby preventing, stopping or even reversing ­neurodegeneration. They are safe for anyone to take, but always check with your doctor first. The best time to start supplementation is today even if you have no symptoms. It takes ­decades of neurodegeneration to develop Alzheimer’s disease.

Low-Dose Lithium

Low doses of nutritional lithium (lithium orotate…not lithium carbonate, which is best-known as a pharmaceutical treatment for bipolar disorder) can shield you against neurodegeneration.

Animal research shows that lithium can stop the development of beta-­amyloid and tau, the abnormal proteins in the brain that are the hallmarks of Alzheimer’s disease…double the activity of an enzyme that protects the membranes of brain cells—an ­enzyme that is low in people with Alzheimer’s…and prevent the onset of Alzheimer’s in mice that have been genetically programmed to develop the disease.

More remarkably, several studies on people show that low-dose lithium can help prevent and even treat Alzheimer’s.

Standout research: In a study published in The British Journal of Psychiatry, Brazilian researchers studied 45 seniors with mild cognitive impairment, the stage of memory loss and mental decline that precedes Alzheimer’s. The researchers divided the seniors into two groups, giving one group low-dose lithium and the other a placebo. After one year, more of the people taking lithium had “stable cognitive performance”—meaning no mental decline. And fewer of those taking lithium developed Alzheimer’s disease.

Another important new finding: In a small study recently published in Alzheimer Disease & Associated Disorders, doctors from Columbia University Medical Center gave 150 milligrams (mg) to 300 mg of lithium daily to people with typical Alzheimer’s symptoms, such as agitation, psychosis (hallucinations, delusions) and sleeping problems. After two weeks, the researchers noted improvements including a “normal sleep cycle, with a marked decrease in paranoia, auditory hallucinations, agitation and aggression.”

If low-dose lithium can treat mild cognitive impairment and Alzheimer’s, it’s likely that it can prevent it.

My advice: If you are over age 50, talk to your doctor about taking 10 mg of lithium orotate daily. If you are under age 50, ask about taking 5 mg. Brands of lithium orotate include Pure Encapsulations, Swanson, KAL and many others.

Vitamin D

Vitamin D influences more than 200 genes including many that play a role in maintaining a healthy brain. It also reduces neuroinflammation—a chronic inflammation of the central nervous system and a key driver of ­Alzheimer’s disease. And vitamin D is a must for the manufacture of serotonin, the ­neurotransmitter that regulates memory and mood. Not surprisingly, vitamin D plays a key role in preventing Alzheimer’s.

New scientific evidence: A 12-year study of 916 seniors, published in ­Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, found a link between low vitamin D levels and cognitive decline. Seniors with low blood levels of vitamin D had faster cognitive decline and were nearly three times more likely to develop Alzheimer’s, compared with people with normal blood levels of vitamin D. The only way to determine if your blood levels of vitamin D are normal is a vitamin D blood test. You can have your physician order the test.

My advice: Maintaining a blood level of 50 nanograms per milliliter (ng/ml) is best for preventing Alzheimer’s. If your blood level is lower, talk to your doctor about taking 5,000 IU of vitamin D-3 daily for three months. If levels still are lower than 50 ng/ml, continue this dose and check again in three months. Once you have achieved 50 ng/ml, take a maintenance dose of 2,000 IU daily. Have blood levels checked yearly.

Vitamin B-12

Vitamin B-12 plays a key role in the synthesis of every neurotransmitter—the chemicals that relay messages from neuron to neuron. It also is a must for the health of the myelin sheath, which protects neurons. B-12 also helps lower levels of homocysteine, an amino acid that is toxic to brain cells. But as you age, your ability to absorb vitamin B-12 decreases—and if blood levels are low, you’re more likely to get Alzheimer’s.

Standout scientific research: A study published in Current Alzheimer ­Research found a link between B-12 and ­Alzheimer’s—people with low blood levels of B-12 were about four times more likely to have Alzheimer’s disease. (People with low levels of B-12 and high levels of homocysteine were about 30 times more likely to have Alzheimer’s.)

And in an eight-year study of 501 people age 60 and older, published in JAMA Psychiatry, those with the highest blood levels of vitamin B-12 had the slowest rate of brain atrophy—that is, the higher the B-12 level, the less the brain shrank with age. That’s an important finding because brain atrophy is another hallmark of Alzheimer’s disease.

My advice: Anyone who wants to prevent Alzheimer’s should take at least 1,000 micrograms (mcg) of vitamin B-12 daily—for maximum absorption, take a sublingual form. (A sublingual capsule or liquid supplement is put ­under the tongue.) Brands include Pure Encapsulations, Nature Made and more.

Beware: In the US, B-12 levels are considered “normal” as long as they are above 200 picograms per milliliter (pg/ml). In Europe and Japan, normal levels are at 500 pg/ml and above. I consider the US “normal” range one of the tragedies of American medicine, dooming many people to cognitive decline. If your physician tells you that your B-12 levels are “normal,” ask what your levels are.

Curcumin

Curcumin is the principle component of turmeric, the spice that flavors curries. Research shows curcumin is ­neuroprotective in many ways, including stopping the formation of beta-amyloid.

Standout research: People age 40 to 60 who took a daily curcumin supplement had lower blood levels of beta-­amyloid, according to a study conducted by researchers at The Ohio State University and published in Nutrition Journal. 

My advice: Take 500 mg of curcumin twice daily with meals. Good brands include Doctor’s Best, Jarrow Formulas, Now, Source Naturals, Thorne Research and many others.

My favorite brain-protecting ­curcumin supplement is one I formulated myself—Curcumasorb Mind from Pure Encapsulations. It contains Meriva, a highly absorbable form of curcumin, as well as many other plant extracts shown to be neuroprotective.