People living with HIV often worry about how the virus affects their brain function. In the early days of the epidemic, as researchers learned that HIV itself can damage the brain, we feared AIDS dementia complex (ADC). Even today, milder cognitive decline is common among people living with HIV—about 53 percent, according to one U.S. study published in July. But some recent news is more reassuring. Below, four recent research brainstorms.

It's immune health, not your viral load that counts
This might encourage those who have trouble keeping their viral loads undetectable: A study from Argentina suggests that immune health might protect against cognitive decline, even when HIV isn't fully suppressed. Among 260 positive people in the study—all with CD4 counts above 350 but not necessarily with undetectable viral loads—scores on tests of brain function were the same for those with undetectable viral loads on meds as for those who hadn't yet started treatment (average viral load: 21,000). Only age made a difference—younger participants did better.

HIV treatment might produce protective immunity in the brain
This was documented in monkeys dosed with HIV meds, compared with an untreated control group. (All the animals had simian HIV.) The drugs used in this study (from the Scripps Research Institute in La Jolla, California) weren't even among those that penetrate the central nervous system (CNS)—the ones some researchers believe should help prevent HIV from damaging the brain. A possible reason for this? HIV meds calm the immune system and prevent it from producing a substance that's potentially toxic to our gray matter: interferon-alfa. (Sound familiar? A manufactured version is used to treat hepatitis B and C.)

An HIV subtype that seems most likely to cause dementia is rare in the United States
In the first research to suggest that some subtypes of the virus might be more likely than others to lead to dementia, Johns Hopkins researchers concluded that the HIV subtype D is linked to more cases of dementia than other HIV types. Subtype D is rare in this country; it's prevalent in Eastern and Central Africa.

You can control your brain health
In many studies (some involving HIV, some not), brain health appears connected to matters within our control. For instance, sedentary lifestyle was associated with worse cognitive functioning in a large study reported this past May. Here are ways to stay in shape and possibly keep your brain ticking along:

  • Exercise (and keep on doing it).
  • Maintain a normal weight for your height and age.
  • Preserve the health of your immune system, heart and kidneys.
  • Keep your blood pressure in check.
  • Get help if you are depressed.
  • Nourish a strong network of friends and family.