Many investors rely on dividend stocks to pay them regular income and provide solid growth over time. Given how many stocks don't pay a dividend at all, it's impressive for a company to be able to maintain and increase their dividend payments over time. Being able to grow steadily through good times and bad is truly a mark of success, and it takes that kind of growth to support dividend payments even during recessions and slowdowns.

In that light, one of the hallmark achievements a company can attain is to become a Dividend Aristocrat. Maintained by Standard and Poor's, the list of Dividend Aristocrats includes members of the S&P 500 that have increased their annual dividends every year for at least 25 years. In order to qualify, a stock has to meet a number of other factors as well, including minimum market cap and daily trading volume requirements. S&P recently announced its annual rebalancing of the index, so let's take a look at who's in and who's out among the dividend elite.

New kids on the block
Three companies have reached the 25-year mark for dividend increases and will therefore join the Dividend Aristocrats after the market's close on Friday. They include McCormick (NYSE: MKC), Hormel Foods (NYSE: HRL), and Ecolab (NYSE: ECL).

It's interesting that all three of the new companies are consumer goods stocks. Already, consumer stocks currently make up more than 40% of the index. But as a defensive sector, consumer stocks are less prone to big downswings during economic slowdowns. McCormick dominates the spice aisle at your grocery store, yet is value-priced and has returns on equity exceeding 26%. Hormel's Spam may not be your favorite food, but the company has successfully navigated international trade tensions and commodity price hikes to stay profitable. And Ecolab has turned home cleaning products into a $6 billion business that's a necessity for many consumers.

Coming to an end
On the other hand, three stocks lost their status as Dividend Aristocrats this year. Eli Lilly (NYSE: LLY), Supervalu (NYSE: SVU), and Integrys Energy (NYSE: TEG) all failed to increase their dividends for the first time in a quarter century or more.

For Lilly and Integrys, the news wasn't disastrous for shareholders, as neither one actually cut their dividend. But for big pharma Lilly, the need to conserve cash in hopes of making acquisitions that can bolster its drug pipeline outweighed the value of making a token dividend increase. And for Integrys, its current dividend represents a payout ratio of well over 100%, meaning that it isn't earning enough to cover its payouts.

Supervalu, on the other hand, cut its dividend early this year, so falling off the list came as no surprise at all. Ultra-thin margins in the supermarket industry have many investors looking for consolidation, and Supervalu is a possible acquirer for Winn-Dixie and its 500 stores.

Tough times for the Aristocrats
Overall, the list of the strongest dividend stocks has seen better days. Since 2007, the number of Dividend Aristocrats has fallen from 60 to 43, and that number will stay constant this year. The damage to financial stocks in particular was a major cause of the reduction, and the market meltdown in late 2008 and early 2009 did more damage beyond the financial sector.

Now, some of those fallen Aristocrats are raising dividends or contemplating future dividend increases. Yet even as they do, it'll take until 2035 for them to reappear on the list -- assuming all goes well.

Surprisingly, there's no ETF covering solely this list of stocks. But the SPDR S&P Dividend ETF (NYSE: SDY) tracks the related High-Yield Dividend Aristocrats index, holding around 60 stocks that include some fallen past Aristocrat stocks.

Stay smart
Being included on the Dividend Aristocrats list is no guarantee of future success. But as a symbol of strong past performance, making the list is the pinnacle of achievement for a dividend stock. If you like dividend stocks, Aristocrats -- including their newest members -- should be at the top of your research list.

For more great dividend stock ideas, click here for 13 strong candidates for your equity income portfolio.